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Hiraba H, Nishio K, Takeuchi Y, Ito T, Yamamori T, Kamimoto A. Application of one-piece endodontic crowns fabricated with CAD-CAM system to molars. JAPANESE DENTAL SCIENCE REVIEW 2024; 60:81-94. [PMID: 38303746 PMCID: PMC10830429 DOI: 10.1016/j.jdsr.2023.12.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2023] [Revised: 12/04/2023] [Accepted: 12/26/2023] [Indexed: 02/03/2024] Open
Abstract
Computer-aided design-computer-aided manufacturing (CAD-CAM) systems have been widely used as a fabrication method for restorations because of their high efficiency and accuracy, which significantly reduces fabrication time. However, molars with insufficient clearance or short clinical crown lengths require retention holes or grooves on the preparation, making it difficult to replicate the shapes with the CAM milling system. In these cases, restorations using the lost-wax method are selected. This article focuses on one-piece endodontic crowns (endocrowns) fabricated with a CAD-CAM system (CAD-CAM endocrowns), in which their posts and crowns are integrated. Articles from July 2012 to August 2023 were searched in PubMed with the keyword "endocrown". This review discusses the application of CAD-CAM endocrowns to molars from the viewpoint of model experiment (fracture resistance, adaptation) and clinical research. This technique, which allows margins and internal gaps to be set within the clinically acceptable range, is reported to be an effective way of restoring molars with high survival rates in clinical research.
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Affiliation(s)
- Haruto Hiraba
- Department of Dental Materials, Nihon University School of Dentistry, 1-8-13, Kanda-Surugadai, Chiyoda-ku, Tokyo 101-8310, Japan
- Division of Biomaterials Science, Dental Research Center, Nihon University School of Dentistry, 1-8-13 Kanda-Surugadai, Chiyoda-ku, Tokyo 101-8310, Japan
| | - Kensuke Nishio
- Department of Complete Denture Prosthodontics, Nihon University School of Dentistry, 1-8-13 Kanda-Surugadai, Chiyoda-ku, Tokyo 101-8310, Japan
| | - Yoshimasa Takeuchi
- Department of Comprehensive Dentistry and Clinical Education, Nihon University School of Dentistry, 1-8-13, Kanda-Surugadai, Chiyoda-ku, Tokyo 101-8310, Japan
| | - Takashi Ito
- Center of Innovative Clinical Medicine, Okayama University Hospital, 2-5-1 Shikata-cho, Kita-ku, Okayama 700-8525, Japan
| | - Tetsuo Yamamori
- Department of Prosthetic Dentistry, School of Dentistry, Ohu University School of Dentistry, 31-1 Misumido, Tomita, Koriyama, Fukushima 963-8611, Japan
| | - Atsushi Kamimoto
- Department of Comprehensive Dentistry and Clinical Education, Nihon University School of Dentistry, 1-8-13, Kanda-Surugadai, Chiyoda-ku, Tokyo 101-8310, Japan
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Luo Y, Li J, Liu L, Ye L, Song D, Huang D. Comparison of the Outcome of Intentional Replantation in Teeth with or without Periodontal Involvement: A Retrospective Study. J Endod 2024; 50:944-953. [PMID: 38588976 DOI: 10.1016/j.joen.2024.03.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2024] [Revised: 03/25/2024] [Accepted: 03/31/2024] [Indexed: 04/10/2024]
Abstract
OBJECTIVE Intentional replantation (IR) is considered as a viable treatment option to preserve the teeth with apical periodontitis. This study aimed to compare the treatment outcomes of IR in teeth with or without periodontal involvement, and to investigate the influence of related factors. METHODS A total of 157 teeth with a documented history of IR between September 2012 and November 2022 and a follow-up duration of more than 1 year were included. The samples included 100 teeth with simple apical periodontitis and 57 teeth with combined periodontal-endodontic lesions (CPEL). Clinical and radiographic criteria were used to evaluate treatment outcomes including functional retention and extraction. Chi-square analyses and Fisher's exact tests were used to compare bivariate associations between outcomes and clinical or demographic variables. Kaplan-Meier analyses were used to evaluate the cumulative survival rate of the intentionally replanted teeth. RESULTS The overall cumulative survival rates were 93.0% at 1 year, 76.7% at 5 years, and 56.2% at 10 years. Among the 100 teeth with simple apical periodontitis, the survival rates were 93.0%, 86.7%, and 78.8% at the same time points. In contrast, 57 teeth with CPEL exhibited survival rates of 93.0%, 65.0%, and 36.9%, respectively. The primary postoperative complications that led to extraction were periodontal involvement (51.9%), tooth fracture (18.5%), external root resorption (18.5%), and persistent apical periodontitis (11.1%). The outcomes of teeth with CPEL were significantly affected by the presence of a sinus tract and crown restoration. In contrast, no significant prognostic factors were identified for teeth without periodontal involvement. CONCLUSION The long-term prognosis of teeth with CPEL is significantly worse than those with simple apical periodontitis. The main reason of extraction was periodontal involvement. Regular periodontal maintenance and appropriate crown restoration may help to improve the prognosis for teeth with CPEL.
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Affiliation(s)
- Yu Luo
- State Key Laboratory of Oral Diseases & National Center for Stomatology & National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, Sichuan, China; Department of Conservative Dentistry and Endodontics, West China Hospital of Stomatology, Sichuan University, Chengdu, Sichuan, China
| | - Jiatong Li
- State Key Laboratory of Oral Diseases & National Center for Stomatology & National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, Sichuan, China; Department of Conservative Dentistry and Endodontics, West China Hospital of Stomatology, Sichuan University, Chengdu, Sichuan, China
| | - Liu Liu
- State Key Laboratory of Oral Diseases & National Center for Stomatology & National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, Sichuan, China; Department of Conservative Dentistry and Endodontics, West China Hospital of Stomatology, Sichuan University, Chengdu, Sichuan, China
| | - Ling Ye
- State Key Laboratory of Oral Diseases & National Center for Stomatology & National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, Sichuan, China; Department of Conservative Dentistry and Endodontics, West China Hospital of Stomatology, Sichuan University, Chengdu, Sichuan, China
| | - Dongzhe Song
- State Key Laboratory of Oral Diseases & National Center for Stomatology & National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, Sichuan, China; Department of Conservative Dentistry and Endodontics, West China Hospital of Stomatology, Sichuan University, Chengdu, Sichuan, China.
| | - Dingming Huang
- State Key Laboratory of Oral Diseases & National Center for Stomatology & National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, Sichuan, China; Department of Conservative Dentistry and Endodontics, West China Hospital of Stomatology, Sichuan University, Chengdu, Sichuan, China.
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Sang Z, Ren Z, Yu J, Wang Y, Liao H. Biomechanical analysis of fixation methods for bone flap repositioning after lateral orbitotomy approach: A finite element analysis. JOURNAL OF STOMATOLOGY, ORAL AND MAXILLOFACIAL SURGERY 2024:101938. [PMID: 38851586 DOI: 10.1016/j.jormas.2024.101938] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/14/2024] [Revised: 05/28/2024] [Accepted: 06/05/2024] [Indexed: 06/10/2024]
Abstract
OBJECTIVE In ophthalmic surgery, different materials and fixation methods are employed for bone flap repositioning after lateral orbitotomy approach (LOA), yet there is no unified standard. This study aims to investigate the impact of different fixation strategies on orbital stability through Finite Element Analysis (FEA) simulations of the biomechanical environment for orbital rim fixation in LOA. METHODS A Finite Element Model (FEM) was established and validated to simulate the mechanical responses under various loads in conventional lateral orbitotomy approach (CLOA) and deep lateral orbital decompression (DLOD) using single titanium plate, double titanium plates, and double absorbable plates fixation methods. The simulations were then validated against clinical cases. RESULTS Under similar conditions, the maximum equivalent stress (MES) on titanium alloy fixations was greater than that on absorbable plate materials. Both under static and physiological conditions, all FEM groups ensured structural stability of the system, with material stresses remaining within safe ranges. Compared to CLOA, DLOD, which involves the removal of the lateral orbital wall, altered stress conduction, resulting in an increase of MES and maximum total deformation (MTD) by 1.96 and 2.62 times, respectively. Under a horizontal load of 50 N, the MES in FEM/DLOD exceeded the material's own strength, with an increase in MES and MTD by 3.18 and 6.64 times, respectively, compared to FEM/CLOA. Under a vertical force of 50 N, the MES sustained by each FEM was within safe limits. Bone flap rotation angles remained minimally varied across scenarios. During follow-up, the 12 patients validated in this study did not experience complications related to the internal fixation devices. CONCLUSION Under static or physiological conditions, various fixation methods can effectively maintain stability at the orbitotomy site, and absorbable materials, with their smoother stress transmission properties, are more suited for application in CLOA. Among titanium plate fixations, single titanium plates can better withstand vertical stress, while double titanium plates are more capable of handling horizontal stress. Given the change in the orbital mechanical behavior due to DLOD, enhanced fixation strength should be considered for bone flap repositioning.
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Affiliation(s)
- Zexi Sang
- School of Optometry, Jiangxi Medical College, Nanchang University, China; Jiangxi Research Institute of Ophthalmology and Visual Science, China; Jiangxi Provincial Key Laboratory for Ophthalmology, China
| | - Zhangjun Ren
- School of Optometry, Jiangxi Medical College, Nanchang University, China; Jiangxi Research Institute of Ophthalmology and Visual Science, China; Jiangxi Provincial Key Laboratory for Ophthalmology, China
| | - Jinhai Yu
- School of Optometry, Jiangxi Medical College, Nanchang University, China; Jiangxi Research Institute of Ophthalmology and Visual Science, China; Jiangxi Provincial Key Laboratory for Ophthalmology, China
| | - Yaohua Wang
- The Affiliated Eye Hospital, Jiangxi Medical College, Nanchang University, China; Jiangxi Clinical Research Center for Ophthalmic Disease, China
| | - Hongfei Liao
- The Affiliated Eye Hospital, Jiangxi Medical College, Nanchang University, China; Jiangxi Clinical Research Center for Ophthalmic Disease, China.
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Hofsteenge JW, Carvalho MA, Botenga ELF, Cune MS, Özcan M, Magne P, Gresnigt MMM. Effect of preparation design on fracture strength of compromised molars restored with direct composite resin restorations: An in vitro and finite element analysis study. J Prosthet Dent 2024; 131:1150-1158. [PMID: 38670907 DOI: 10.1016/j.prosdent.2024.03.039] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2023] [Revised: 03/27/2024] [Accepted: 03/29/2024] [Indexed: 04/28/2024]
Abstract
STATEMENT OF PROBLEM More data are needed on the influence of preparation design on the fracture strength, failure type, repairability, and polymerization-induced cracks of molar teeth restored with direct composite resin restorations. PURPOSE This in vitro and finite element analysis study investigated the effect of different preparation designs on fracture strength, failure type, repairability, tooth deformation, and the formation of polymerization-induced cracks of compromised molars restored with direct composite resin restorations. MATERIAL AND METHODS Human molars (n=64) were randomly assigned to 4 different preparation designs: undermined inlay (UI), extended inlay (EI), restricted overlay (RO), and extended overlay (EO). The teeth were restored using direct composite resin and subjected to artificial thermomechanical aging in a mastication simulator, followed by load-to-failure testing. Three-dimensional (3D) finite element analysis was conducted to assess tooth deformation. Polymerization-induced cracks were evaluated using optical microscopy and transillumination. The fracture strength data were analyzed using a Kruskal-Wallis test, while the failure mode, repairability, and polymerization cracks were analyzed using the Fisher exact test (α=.05). RESULTS All specimens withstood thermomechanical aging, and no statistically significant difference in fracture strength was observed among the 4 preparation designs (P>.05). The finite element analysis showed differences in tooth deformation, but no correlation was observed with in vitro fracture resistance. The RO and EO groups presented significantly more destructive failures compared with the UI and EI groups (P<.01). The RO group had significantly fewer repairable failures than the UI and EI groups (P=.024). A correlation was found between higher frequencies of repairability and higher tooth deformation. A significant correlation between the increase in microfractures and preparation design was observed (P<.01), with the UI group exhibiting a higher increase in microfracture size compared with the EO group (P<.05). CONCLUSIONS No influence of preparation design on the fracture strength of compromised molars restored with direct composite resin restorations was evident in this study, but the failure mode of cusp coverage restorations was more destructive and often less repairable. The finite element analysis showed more tooth deformation in inlay preparations, with lower stresses within the root, leading to more reparable fractures. Since cusp coverage direct composite resin restorations fractured in a more destructive manner, this study suggests that even a tooth with undermined cusps should be restored without cusp coverage.
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Affiliation(s)
- Jelte W Hofsteenge
- Postgraduate student, Department of Restorative Dentistry, Center for Dentistry and Oral Hygiene, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands.
| | - Marco Aurelio Carvalho
- Associate Professor, School of Dentistry, Evangelical University of Goias (UniEVANGÉLICA), Anapolis, Brazil
| | - Elenoor L F Botenga
- Graduate student, Department of Restorative Dentistry, Center for Dentistry and Oral Hygiene, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands
| | - Marco S Cune
- Professor, Department of Restorative Dentistry, Center for Dentistry and Oral Hygiene, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands
| | - Mutlu Özcan
- Professor, Division of Dental Biomaterials, Clinic for Reconstructive Dentistry, Center of Dental Medicine, University of Zurich, Zurich, Switzerland
| | - Pascal Magne
- Director, Center for Education and Research in Biomimetic Restorative Dentistry (CER BRD), Beverly Hills, Calif
| | - Marco M M Gresnigt
- Associate Professor, Department of Restorative Dentistry, Center for Dentistry and Oral Hygiene, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands
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Kaenploy J, Li R, Makowka S, Sadid-Zadeh R. Fracture resistance of cement-retained lithium disilicate implant-supported crowns: Effect of material used for two-piece abutments. J Prosthodont 2024. [PMID: 38807201 DOI: 10.1111/jopr.13871] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2023] [Revised: 03/14/2024] [Accepted: 05/13/2024] [Indexed: 05/30/2024] Open
Abstract
PURPOSE This study compared the fracture strength of single lithium disilicate implant-supported crowns fabricated on two-piece abutments with various materials: ceramic-reinforced PEEK, zirconia, and lithium disilicate. MATERIALS AND METHODS Thirty-six implants were embedded in acrylic cylinders. A two-piece abutment and a crown were designed following a pre-operation scan for a maxillary left central incisor. The designed crown was used to fabricate 36 lithium disilicate crowns. The designed abutment was used to manufacture 36 abutments from 3 materials, 12 each: (A) zirconia; (B) lithium disilicate; and (C) ceramic-reinforced PEEK. Abutments were surface treated and bonded on the titanium base abutments with resin cement. Then, lithium disilicate crowns were bonded on the assigned abutments. Specimens were then subjected to dynamic loading for 1,200,000 cycles. The fracture strength (N) of the assembly was assessed using a universal testing machine. One-way ANOVA followed by multiple comparison tests was used to evaluate the effect of abutment material on the fracture strength of single implant-supported restorations at a significance of .05. RESULTS The average fracture strength for the groups with zirconia, PEEK, and lithium disilicate two-piece abutments were 1362N ± 218N, 1235N ± 115N, and 1472N ± 171N, respectively. There was a significant (p < 0.05) difference in fracture strength among the groups. The lithium disilicate group had significantly higher fracture strength (p = 0.0058) than the group with PEEK; however, there was no significant (p > 0.05) difference between the other groups. CONCLUSIONS Two-piece abutments restored with lithium disilicate crowns investigated in the study have the potential to withstand the average physiological occlusal forces in the anterior region.
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Affiliation(s)
- Jekita Kaenploy
- Department of Restorative Sciences, College of Dentistry, University of Oklahoma, Oklahoma City, Oklahoma, USA
| | - Rui Li
- Department of Restorative Dentistry, School of Dental Medicine, University at Buffalo, Buffalo, New York, USA
| | - Steven Makowka
- School of Dental Medicine, University at Buffalo, Buffalo, New York, USA
| | - Ramtin Sadid-Zadeh
- Department of Restorative Sciences, School of Dentistry, University of Alabama at Birmingham, Birmingham, Alabama, USA
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Mitchell A, Heales L, Treleaven J, Too B, Tyrrell R, Dinsdale A. Pain-free bite force in a healthy population: Within-session test-retest reliability in different sitting positions. J Oral Rehabil 2024. [PMID: 38685714 DOI: 10.1111/joor.13720] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2023] [Revised: 03/20/2024] [Accepted: 04/18/2024] [Indexed: 05/02/2024]
Abstract
BACKGROUND Pain-free bite force (PFBF) is a promising measure to evaluate bite function in temporomandibular disorders (TMDs), yet the reliability of the measure is unknown. OBJECTIVES Establish the (1) within-session test-retest reliability of PFBF in a healthy population for a single and mean of three trials in supported and unsupported sitting; (2) standard error of measurement (SEM) and minimal detectable change (MDC). METHODS Thirty healthy participants (n = 15 female, mean [SD] age = 34.4 [11.0] years) completed two sessions (30-60 min apart) comprising three PFBF trials on each side, in both supported and unsupported sitting, to provide data for 60 (30 participants × two sides) test-retest assessments. Test-retest reliability for the first trial and mean of three trials in each position were determined using intraclass correlation coefficients (ICCs), before calculating the corresponding SEM and MDC for males (M) and females (F) respectively. RESULTS Within-session reliability was considered excellent for a single trial in supported sitting (ICC = 0.85; SEM M/F = 99/84 N; MDC M/F = 275/232 N) and unsupported sitting (ICC = 0.91; SEM M/F = 72/59 N, MDC M/F = 200/163 N), and for a mean of three trials in supported sitting (ICC = 0.89; SEM M/F = 66/79 N, MDC M/F = 182/220 N) and unsupported sitting (ICC = 0.92; SEM M/F = 64/59 N, MDC M/F = 177/164 N). CONCLUSION Single and a mean of three trials in supported and unsupported sitting appear reliable methods to measure PFBF in a healthy population. Testing PFBF using a mean of three trials in unsupported sitting appears superior over other methods though due to higher test-retest reliability, and lower SEM and MDC. Future studies should examine the reliability of PFBF in TMD populations.
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Affiliation(s)
- Andrew Mitchell
- School of Health and Rehabilitation Sciences, The University of Queensland, St Lucia, Queensland, Australia
- Physiotherapy Department, The Prince Charles Hospital, Chermside, Queensland, Australia
| | - Luke Heales
- School of Health, Medical and Applied Sciences, Central Queensland University, Rockhampton, Queensland, Australia
| | - Julia Treleaven
- School of Health and Rehabilitation Sciences, The University of Queensland, St Lucia, Queensland, Australia
| | - Brendan Too
- School of Health and Rehabilitation Sciences, The University of Queensland, St Lucia, Queensland, Australia
- Joint Health Command, Serco, RAAF Base, Williamtown, New South Wales, Australia
| | - Ryan Tyrrell
- School of Health and Rehabilitation Sciences, The University of Queensland, St Lucia, Queensland, Australia
- Physiotherapy Department, Queen Elizabeth II Jubilee Hospital, Coopers Plains, Queensland, Australia
| | - Alana Dinsdale
- School of Health and Rehabilitation Sciences, The University of Queensland, St Lucia, Queensland, Australia
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Bresser RA, Hofsteenge JW, Buijs GJ, van den Breemer CRG, Özcan M, Cune MS, Gresnigt MMM. Partial glass-ceramic posterior restorations with margins beyond or above the cemento-enamel junction: An observational retrospective clinical study. J Prosthodont Res 2024:JPR_D_23_00219. [PMID: 38684406 DOI: 10.2186/jpr.jpr_d_23_00219] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/02/2024]
Abstract
PURPOSE This observational retrospective clinical study aimed to investigate the survival and success rates of partial indirect lithium disilicate restorations with margins extending above or beyond the cementoenamel junction (CEJ). METHODS The study included patients who underwent partial indirect lithium disilicate restorations with immediate dentin sealing (IDS) between January 2008 and October 2018. All the restorations were placed in a single general dental practice following a standardized protocol. The impact of various predictive variables on the survival rates was assessed. Moreover, modified United States Public Health Service (USPHS) criteria were used to evaluate the survival quality. RESULTS Totally 1146 partial indirect lithium disilicate restorations in 260 patients were evaluated over an average period of 7.5 years. The cumulative survival and success rates were 97.3% and 95.3%, respectively. Margins extending beyond the cemento-enamel junction did not increase the risk of success or survival failure (P > 0.05). Patients with a high risk of caries, male sex, or non-vital teeth had a significantly higher risk of restoration failure (P < 0.05). Restorations with longer clinical service times exhibited marginally lower clinical quality (P < 0.001). CONCLUSIONS Partial indirect glass-ceramic restorations demonstrated survival and success rates of 97.3% and 95.3%, respectively, over an extended period. However, a higher risk of restoration failure existed in patients with a high caries risk for (pre)molars that had undergone endodontic treatment and in males. In terms of the risk of success or survival failure, comparable results were obtained for the positions of the restoration margin in relation to the cemento-enamel junction.
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Affiliation(s)
- Rijkje A Bresser
- University of Groningen, University Medical Center Groningen, Center for Dentistry and Oral Hygiene, Department of Restorative Dentistry, Groningen, The Netherlands
| | - Jelte W Hofsteenge
- University of Groningen, University Medical Center Groningen, Center for Dentistry and Oral Hygiene, Department of Restorative Dentistry, Groningen, The Netherlands
| | - Gerrit J Buijs
- Buijs Tandartsen, Clinic for General Dentistry, Groningen, The Netherlands
| | - Carline R G van den Breemer
- University of Groningen, University Medical Center Groningen, Center for Dentistry and Oral Hygiene, Department of Restorative Dentistry, Groningen, The Netherlands
| | - Mutlu Özcan
- University of Groningen, University Medical Center Groningen, Center for Dentistry and Oral Hygiene, Department of Restorative Dentistry, Groningen, The Netherlands
- University of Zurich, Center of Dental Medicine, Division of Dental Biomaterials, Clinic for Reconstructive Dentistry, Zurich, Switzerland
| | - Marco S Cune
- University of Groningen, University Medical Center Groningen, Center for Dentistry and Oral Hygiene, Department of Restorative Dentistry, Groningen, The Netherlands
- St. Antonius Hospital, Department of Oral Maxillofacial Surgery, Prosthodontics and Special Dental Care, Nieuwegein, The Netherlands
| | - Marco M M Gresnigt
- University of Groningen, University Medical Center Groningen, Center for Dentistry and Oral Hygiene, Department of Restorative Dentistry, Groningen, The Netherlands
- Martini Hospital, Department of Special Dental Care, Groningen, The Netherlands
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Su JN, Pan YH, Dorj O, Lin JCY, Salamanca E, Chen IW, Wu YF, Chang WJ. Association between oral health status and occlusal bite force in young adults. J Dent Sci 2024; 19:1182-1189. [PMID: 38618102 PMCID: PMC11010718 DOI: 10.1016/j.jds.2023.11.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2023] [Revised: 11/13/2023] [Indexed: 04/16/2024] Open
Abstract
Background/purpose Oral health is related to general health and a person's overall well-being. The aim of the present study was to explore the association between oral health status and bite force among young adults. Materials and methods Maximum bite force (MBF) was measured using Dental Prescale II in conjunction with a pressure-sensitive film and bite force analyzer in 40 young adults aged 20 to 40. Supragingival dental plaque was collected and cultured. Plaque weight, pH, and colony counts were assessed. The decayed, missing, and filled teeth index (DMFT) and body mass index (BMI) were recorded. Results Bite force was negatively correlated with the number of missing teeth and the sum of missing and filled teeth. When the filled-to-remaining-teeth ratio (F/R ratio) was less than 8%, the bite force was significantly higher compared to an F/R ratio of 8-25%. Additionally, the amount of total bacteria was positively correlated with total bite force, and the quantity of Streptococcus mutans (S. mutans) along with total bacteria was positively correlated with bite force in the molar region (∗P < 0.05). The molar region predominantly contributed to bite force. Conclusion Elevated levels of cariogenic bacteria may increase the risk of tooth loss, subsequently leading to reduced bite force. This reduction in bite force can further impact the efficiency of chewing function and, consequently, the quality of life. An F/R ratio above 8% could be easily calculated clinically and could serve as a guide to identify patients, particularly young adults, at risk of reduced bite force.
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Affiliation(s)
- Jo-Ning Su
- School of Dentistry, College of Oral Medicine, Taipei Medical University, Taipei, Taiwan
| | - Yu-Hwa Pan
- School of Dentistry, College of Oral Medicine, Taipei Medical University, Taipei, Taiwan
- Department of Dentistry, Chang Gung Memorial Hospital, Taipei, Taiwan
- Graduate Institute of Dental and Craniofacial Science, Chang Gung University, Taoyuan, Taiwan
- School of Dentistry, College of Medicine, China Medical University, Taichung, Taiwan
| | - Odontuya Dorj
- School of Dentistry, College of Oral Medicine, Taipei Medical University, Taipei, Taiwan
- Department of Dental Technology and Dental Hygiene, School of Dentistry, Mongolian National University of Medical Sciences, Ulaanbaatar, Mongolia
| | - Jerry Chin-Yi Lin
- School of Dentistry, College of Oral Medicine, Taipei Medical University, Taipei, Taiwan
- Department of Oral Medicine, Infection and Immunity, Harvard School of Dental Medicine, Boston, MA, USA
| | - Eisner Salamanca
- School of Dentistry, College of Oral Medicine, Taipei Medical University, Taipei, Taiwan
| | - I-Wen Chen
- School of Dentistry, College of Oral Medicine, Taipei Medical University, Taipei, Taiwan
| | - Yi-Fan Wu
- School of Dentistry, College of Oral Medicine, Taipei Medical University, Taipei, Taiwan
| | - Wei-Jen Chang
- School of Dentistry, College of Oral Medicine, Taipei Medical University, Taipei, Taiwan
- Dental Department, Taipei Medical University, Shuang-Ho Hospital, New Taipei City, Taiwan
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9
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Yousry M, Hammad I, El Halawani M, Aboushelib M. Preparation of ultrathin translucent zirconia laminate veneers using 3D printing reduction guides. J Prosthet Dent 2024; 131:548-553. [PMID: 38480012 DOI: 10.1016/j.prosdent.2024.01.040] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2023] [Revised: 01/25/2024] [Accepted: 01/26/2024] [Indexed: 04/05/2024]
Abstract
Minimizing and controlling the amount of tooth reduction during the preparation of ultrathin laminate veneers is a challenge for minimally invasive dentistry. The use of reduction guides is advised to reach the optimal space required for the definitive restoration without excessive reduction. The digital production of a reduction guide used to control tooth preparation for ultrathin laminate veneers is described.
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Affiliation(s)
- Mahinour Yousry
- PhD Researcher, Division of Fixed Prosthodontics, Department of Conservative Dentistry, Faculty of Dentistry, Alexandria University, Alexandria, Egypt.
| | - Ihab Hammad
- Professor, Division of Fixed Prosthodontics, Department of Conservative Dentistry, Faculty of Dentistry, Alexandria University, Alexandria, Egypt
| | - Mohamed El Halawani
- Lecturer, Division of Fixed Prosthodontics, Department of Conservative Dentistry, Faculty of Dentistry, Alexandria University, Alexandria, Egypt
| | - Moustafa Aboushelib
- Professor, Department of Dental Materials Science, Faculty of Dentistry, Alexandria University, Alexandria, Egypt
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Bresser RA, Carvalho MA, Naves LZ, Melma H, Cune MS, Gresnigt MMM. Biomechanical behavior of molars restored with direct and indirect restorations in combination with deep margin elevation. J Mech Behav Biomed Mater 2024; 152:106459. [PMID: 38394767 DOI: 10.1016/j.jmbbm.2024.106459] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2023] [Revised: 01/30/2024] [Accepted: 02/05/2024] [Indexed: 02/25/2024]
Abstract
STATEMENT OF PROBLEM The existing knowledge is insufficient for comprehending the fatigue survival and fracture resistance of molars that have deep approximal direct and indirect restorations, whether with or without deep margin elevation (DME). PURPOSE The aim of this laboratory and in silico study is to investigate the fatigue survival, fracture strength, failure pattern and tooth deformation of molars restored with DME in combination with a direct or indirect restoration. MATERIAL AND METHODS This study utilized 45 extracted sound human molars, divided into three groups (n = 15). Standardized 100% inter-cuspal inlay preparations were performed, extending 2 mm below the CEJ and immediate dentin sealing (IDS) was applied. Group 1 (Co_1) was restored with direct composite; Group 2 (Hyb_2) with a 2 mm DME of direct composite and a glass-ceramic lithium disilicate restoration; Group 3 (Cer_3) a glass-ceramic lithium disilicate restoration. All specimens were exposed to a fatigue process involving thermal-cyclic loading (50N for 1.2 × 106 cycles at 1.7 Hz, between 5 and 55 °C), if teeth survived, they were fractured using a load-to-failure test and failure types were analyzed. Finite element analysis (FEA) was conducted to assess tooth deformation and tensile stress in the restorations. Statistical evaluation of fracture strength was conducted using the Kruskal-Wallis test. Fisher's exact test was utilized to analyze the fracture types and repairability. A statistical significance level of α < 0.05 was set for all analyses. RESULTS All specimens successfully withstood the fatigue testing procedure, and no statistically significant differences in fracture strength were observed among the three groups (P > 0.05). The Fisher's exact test indicated a significant association between the restorative material and fracture type (F2 = 18.315, df = 2, P = 0.004), but also for repairability (F2 = 13.725, df = 2, P = 0.001). Crown-root fractures were significantly more common in the Cer_3 group compared to the Co_1 group (P = 0.001) and the Co_1 group had significantly more repairable fractures (F2 = 13.197, df = 2, P = 0.001). FEA revealed comparable outcomes of deformation among models and higher maximum tensile stress on models with higher frequency of catastrophic failures. CONCLUSIONS All tested restoration materials exhibited comparable fatigue survival and fracture strength in this laboratory and in silico study. However, it is important to recognize the potential for more severe and irreparable fractures when opting for deeply luted glass-ceramic inlay restorations in clinical practice. In such cases, it would be prudent to consider the alternative option being a direct composite approach, because of its more forgiving fracture types and repairability. CLINICAL IMPLICATIONS Molars with deep approximal direct and indirect restorations, whether with or without DME, are comparable in their fatigue survival and fracture resistance to withstand intra-oral forces. Deep direct restorations exhibit more repairable fractures compared to deeply luted glass-ceramics.
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Affiliation(s)
- Rijkje A Bresser
- University of Groningen, University Medical Center Groningen, Center for Dentistry and Oral Hygiene, Department of Restorative Dentistry, Groningen, the Netherlands.
| | - Marco A Carvalho
- Dental School, Evangelical University of Goias, Anapolis, Brazil
| | - Lucas Z Naves
- University of Groningen, University Medical Center Groningen, Center for Dentistry and Oral Hygiene, Department of Restorative Dentistry, Groningen, the Netherlands
| | - H Melma
- University of Groningen, University Medical Center Groningen, Center for Dentistry and Oral Hygiene, Department of Restorative Dentistry, Groningen, the Netherlands
| | - Marco S Cune
- University of Groningen, University Medical Center Groningen, Center for Dentistry and Oral Hygiene, Department of Restorative Dentistry, Groningen, the Netherlands; St. Antonius Hospital Nieuwegein, Department of Oral Maxillofacial Surgery, Prosthodontics and Special Dental Care, Nieuwegein, the Netherlands
| | - Marco M M Gresnigt
- University of Groningen, University Medical Center Groningen, Center for Dentistry and Oral Hygiene, Department of Restorative Dentistry, Groningen, the Netherlands; Martini Hospital, Department of Special Dental Care, Groningen, the Netherlands
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Molinero-Mourelle P, Abou-Ayash S, Brägger U, Schimmel M, Özcan M, Yilmaz B, Buser R, Al-Haj Husain N. Load bearing capacity of 3-unit screw-retained implant-supported fixed dental prostheses with a mesial and distal cantilever on a single implant: A comparative in vitro study. J Mech Behav Biomed Mater 2024; 151:106395. [PMID: 38244420 DOI: 10.1016/j.jmbbm.2024.106395] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2023] [Revised: 01/08/2024] [Accepted: 01/08/2024] [Indexed: 01/22/2024]
Abstract
OBJECTIVES To assess the mechanical durability of monolithic zirconia implant-supported fixed dental prostheses (iFDP) design on one implant, with a distal and a mesial extension cantilever bonded to a titanium base compared to established designs on two implants. MATERIALS AND METHODS Roxolid Tissue level (TL), and tissue level x (TLX) implants were used to manufacture screw-retained 3-unit iFDPs (n = 60, n = 10 per group), with following configurations (X: Cantilever; I: Implant, T: Test group, C: Control group): T1: X-I-X (TL); T2: X-I-X (TLX); T3: I-I-X (TL); T4: I-I-X (TLX); C1: I-X-I (TL); C2: I-X-I (TLX). The iFDPs were thermomechanically aged and subsequently loaded until fracture using a universal testing machine. The failure load at first crack (Finitial) and at catastrophic fracture (Fmax) were measured and statistical evaluation was performed using two-way ANOVA and Tukey's post-hoc tests. RESULTS The mean values ranged between 190 ± 73 and 510 ± 459 N for Finitial groups, and between 468 ± 76 and 1579 ± 249 N for Fmax, respectively. Regarding Finitial, neither the implant type, nor the iFDP configuration significantly influenced measured failure loads (all p > 0.05). The choice of implant type did not show any significant effect (p > 0.05), while reconstruction design significantly affected Fmax data (I-I-Xa < X-I-Xb < I-X-Ic) (p < 0.05). The mesial and distal extension groups (X-I-X) showed fractures only at the cantilever extension site, while the distal extension group (I-I-X) showed one abutment and one connector fracture at the implant/reconstruction interface. CONCLUSION Results suggest that iFDPs with I-X-I design can be recommended regardless of tested implant type followed by the mesial and distal extension design on one implant abutment (X-I-X).
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Affiliation(s)
- Pedro Molinero-Mourelle
- Department of Reconstructive Dentistry and Gerodontology, School of Dental Medicine, University of Bern, Switzerland
| | - Samir Abou-Ayash
- Department of Reconstructive Dentistry and Gerodontology, School of Dental Medicine, University of Bern, Switzerland
| | - Urs Brägger
- Department of Reconstructive Dentistry and Gerodontology, School of Dental Medicine, University of Bern, Switzerland
| | - Martin Schimmel
- Department of Reconstructive Dentistry and Gerodontology, School of Dental Medicine, University of Bern, Switzerland; Division of Gerodontology and Removable Prosthodontics, University Clinics of Dental Medicine, University of Geneva, Switzerland
| | - Mutlu Özcan
- Clinic of Masticatory Disorders and Dental Biomaterials, Center of Dental Medicine, University of Zurich, Zurich, Switzerland
| | - Burak Yilmaz
- Department of Reconstructive Dentistry and Gerodontology, School of Dental Medicine, University of Bern, Switzerland; Department of Restorative, Preventive and Pediatric Dentistry, School of Dental Medicine, University of Bern, Bern, Switzerland; Division of Restorative and Prosthetic Dentistry, The Ohio State University College of Dentistry, Columbus, OH, USA
| | - Ramona Buser
- Department of Reconstructive Dentistry and Gerodontology, School of Dental Medicine, University of Bern, Switzerland
| | - Nadin Al-Haj Husain
- Department of Reconstructive Dentistry and Gerodontology, School of Dental Medicine, University of Bern, Switzerland; Clinic of Masticatory Disorders and Dental Biomaterials, Center of Dental Medicine, University of Zurich, Zurich, Switzerland.
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Ben Achour A, Apfeld F, Lauer G, Bräuer C, Leonhardt H, Franke A, Lipphaus A, Teicher U, Witzel U, Schröder TA. Development of a test bench for biomechanical simulation-a preliminary study of mandibular forces. Front Bioeng Biotechnol 2024; 12:1335159. [PMID: 38468690 PMCID: PMC10925755 DOI: 10.3389/fbioe.2024.1335159] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2023] [Accepted: 02/07/2024] [Indexed: 03/13/2024] Open
Abstract
Purpose: The aim of this study is to develop a test bench, which integrates different complexity levels and enables in that way a flexible and dynamic testing for mid and long term intervals as well as testing of maximum loads till implant failure of different osteosynthesis systems on the mandible. Material and Methods: For this purpose, an analysis of the state of the art regarding existing test benches was combined with interviews of clinical experts to acquire a list of requirements. Based on these requirements a design for a modular test bench was developed. During the implementation of the test stand, functional tests were continuously carried out and improvements made. Depending on the level of complexity, the test bench can be used either as an incorporated variant or as a standalone solution. In order to verify the performance and the degree of fulfilment of the requirements of these two variants of the test bench, preliminary studies were carried out for all levels of complexity. In these preliminary studies, commercially available osteosynthesis and reconstruction plates were investigated for their biomechanical behaviour and compared with data from the literature. Results: In total, fourteen test runs were performed for the different levels of complexity. Firstly, five test runs were executed to test the simplified load scenario in the incorporated variant of the test bench. High forces could be transmitted without failure of the miniplates. Secondly a quasi-static test scenario was examined using the incorporated variant with simplified load insertion. Five experiments with a number of cycles between 40,896 and 100,000 cycles were carried out. In one case the quasi-static testing resulted in a fracture of the tested reconstruction plate with a failure mode similar to the clinical observations of failure. The last four test runs were carried out using the standalone variant of the test bench simulating complex load patterns via the insertion of forces through imitated muscles. During the test runs joint forces were measured and the amplitude and vector of the resulting joint forces were calculated for both temporomandibular joints. Differences in the force transmission depending on the implant system in comparison to the zero sample could be observed. Conclusion: The presented modular test bench showed to be applicable for examination of the biomechanical behavior of the mandible. It is characterized by the adjustability of the complexity regarding the load patterns and enables the subsequent integration of further sensor technologies. Follow-up studies are necessary to further qualify and optimize the test bench.
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Affiliation(s)
- Anas Ben Achour
- Fraunhofer Institute for Machine Tools and Forming Technology IWU, Dresden, Germany
| | - Florian Apfeld
- Fraunhofer Institute for Machine Tools and Forming Technology IWU, Dresden, Germany
- Biomechanics Research Group, Chair of Product Development, Faculty of Mechanical Engineering, Ruhr University Bochum, Bochum, Germany
| | - Günter Lauer
- Department of Oral and Maxillofacial Surgery, University Hospital Carl Gustav Carus Dresden, Technische Universität Dresden, Dresden, Germany
| | - Christian Bräuer
- Department of Oral and Maxillofacial Surgery, Facial Plastic Surgery, University of Rostock, Rostock, Germany
| | - Henry Leonhardt
- Department of Oral and Maxillofacial Surgery, University Hospital Carl Gustav Carus Dresden, Technische Universität Dresden, Dresden, Germany
| | - Adrian Franke
- Department of Oral and Maxillofacial Surgery, University Hospital Carl Gustav Carus Dresden, Technische Universität Dresden, Dresden, Germany
| | - Andreas Lipphaus
- Biomechanics Research Group, Chair of Product Development, Faculty of Mechanical Engineering, Ruhr University Bochum, Bochum, Germany
| | - Uwe Teicher
- Fraunhofer Institute for Machine Tools and Forming Technology IWU, Dresden, Germany
| | - Ulrich Witzel
- Biomechanics Research Group, Chair of Product Development, Faculty of Mechanical Engineering, Ruhr University Bochum, Bochum, Germany
| | - Tom Alexander Schröder
- Department of Oral and Maxillofacial Surgery, University Hospital Carl Gustav Carus Dresden, Technische Universität Dresden, Dresden, Germany
- Else Kröner Fresenius Center for Digital Health, Technische Universität Dresden, Dresden, Germany
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Jurado CA, Lee D, Ramirez P, Cortes-Treviño DA, Tsujimoto A. Fracture Resistance of Chairside CAD/CAM Lithium Disilicate-reinforced Ceramic Occlusal Veneers With and Without Margin and Full Coverage Crowns. Oper Dent 2024; 49:84-90. [PMID: 38058016 DOI: 10.2341/23-043-l] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/31/2023] [Indexed: 12/08/2023]
Abstract
OBJECTIVE The aim of this investigation was to compare the fracture resistance of chairside computer-aided design and computer-aided manufacturing (CAD/CAM) lithium disilicate-reinforced ceramic occlusal veneers with and without margin and traditional full coverage premolar crowns. METHODS AND MATERIALS A total of 60 chairside CAD/CAM lithium disilicate-reinforced ceramic (Amber Mill, Hass Bio) restorations were designed and fabricated with a chairside CAD/CAM system (CEREC Dentsply Sirona). The restorations were divided into three groups (n=20): 1) occlusal veneer with 1.0-mm uniform occlusal thickness and with chamfer margin; 2) occlusal veneer with 1.0-mm uniform occlusal thickness and without margin; and 3) full coverage crown with uniform occlusal thickness and gingival margin. Occlusal veneers and crowns were cemented with dual cured resin luting cement (Multilink, Ivoclar Vivadent) to printed resin dies, load cycled (5 million load cycles at 1 Hz with 275 N force), and then loaded until fracture. Load at break (LB) and peak load (PL) until fracture were recorded. Scanning electron microscope images of the tested restorations on the abutments were obtained. RESULTS Fracture strengths were different depending on the design of the restoration. There was no significant difference in fracture strength between the two types of occlusal veneer (LB: 1132.45 N; PL: 1143.30 N for veneers with margin; LB: 1149.25 N; PL: 1219.05 N for veneers without margin). Full coverage crowns showed the lowest fracture resistance (LB: 936.26 N, PL: 976.42 N), which was significantly lower than both designs of occlusal veneer. CONCLUSIONS The fracture resistance of the CAD/CAM lithium disilicate-reinforced ceramic restorations was influenced by the design. Occlusal veneers with and without margin displayed higher fracture resistance than traditional crowns.
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Affiliation(s)
- C A Jurado
- Carlos Alberto Jurado, DDS, MS, clinical associate professor, University of Iowa College of Dentistry and Dental Clinics, Iowa City, IA, USA
| | - D Lee
- Damian Lee, DDS, MS, associate professor and chair, Department of Prosthodontics, Tufts University School of Dental Medicine, Boston, MA, USA
| | - P Ramirez
- Paulette Ramirez, BS, dental student, Texas Tech University Health Sciences Center El Paso, Woody L. Hunt School of Dental Medicine, El Paso, TX, USA
| | - D A Cortes-Treviño
- Daniel Alberto Cortes-Treviño, DDS, MS, private practice, Dallas, TX, USA
| | - A Tsujimoto
- *Akimasa Tsujimoto, DDS, PhD, professor and chair, Department of Operative Dentistry, Aichi Gakuin University School of Dentistry, Nagoya, Aichi, Japan; adjunct associate professor, Department of Operative Dentistry, University of Iowa College of Dentistry, Iowa City, Iowa, USA; visiting associate professor, Department of General Dentistry, Creighton University School of Dentistry, Omaha, NE, USA
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14
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Garoushi S, Barlas D, Vallittu PK, Uctasli MB, Lassila L. Fracture behavior of short fiber-reinforced CAD/CAM inlay restorations after cyclic fatigue aging. Odontology 2024; 112:138-147. [PMID: 37097420 PMCID: PMC10776750 DOI: 10.1007/s10266-023-00815-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2023] [Accepted: 04/17/2023] [Indexed: 04/26/2023]
Abstract
The aim of this study was to assess the fracture behavior of molar teeth restored with MOD inlays made of experimental short fiber-reinforced CAD/CAM composite block (SFRC CAD) before and after cyclic fatigue aging. Standardized MOD cavities were prepared on 60 intact mandibular molars. Three groups of CAD/CAM made inlay restorations (Cerasmart 270, Enamic, and SFRC CAD) were fabricated (n = 20/group). All restorations were luted with self-adhesive dual-cure resin cement (G-Cem One). Half of restored teeth per each group (n = 10) were quasi-statically loaded until fracture without aging. The other half underwent cyclic fatigue aging for 500,000 cycles (Fmax = 150 N) before being loaded quasi-statically until fracture. Then, the fracture type was visually inspected. The microstructure and elemental content of CAD/CAM materials were assessed using SEM and EDS. Two-way analysis of variance (ANOVA) was used to statistically examine the data, and it was followed by the Tukey HSD test (α = 0.05). ANOVA demonstrated that both material type and aging had a significant effect (p < 0.05) on the load-bearing capacity values of the restorations. Teeth restored with SFRC CAD showed significantly the highest (p < 0.05) load-bearing capacity (2535 ± 830 N) after fatigue aging among all groups. SEM images showed the ability of short fibers in SFRC CAD composite to redirect and hinder crack propagation. With regard to fracture mode, Enamic group revealed 85% of catastrophic failure (vs. 45% and 10% for Cerasmart 270 and SFRC CAD, respectively). Large MOD cavities on molar teeth were most favorably restored with SFRC CAD inlays, yielding the highest load-bearing capacity and more restorable failures.
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Affiliation(s)
- S Garoushi
- Department of Biomaterials Science and Turku Clinical Biomaterial Center-TCBC, Institute of Dentistry, University of Turku, Turku, Finland.
| | - D Barlas
- Department of Restorative Dentistry, Faculty of Dentistry, University of Gazi, Ankara, Turkey
| | - P K Vallittu
- Department of Biomaterials Science and Turku Clinical Biomaterial Center-TCBC, Institute of Dentistry, University of Turku, Turku, Finland
- Wellbeing Services County of South-West Finland, Turku, Finland
| | - M B Uctasli
- Department of Restorative Dentistry, Faculty of Dentistry, University of Gazi, Ankara, Turkey
| | - L Lassila
- Department of Biomaterials Science and Turku Clinical Biomaterial Center-TCBC, Institute of Dentistry, University of Turku, Turku, Finland
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15
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Alsarani MM. Influence of aging process and restoration thickness on the fracture resistance of provisional crowns: A comparative study. Saudi Dent J 2023; 35:939-945. [PMID: 38107052 PMCID: PMC10724475 DOI: 10.1016/j.sdentj.2023.07.017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2023] [Revised: 07/12/2023] [Accepted: 07/18/2023] [Indexed: 12/19/2023] Open
Abstract
Background The advancement of digital dentistry enhanced the fabrication of indirect provisional restorations utilizing durable materials, yet the performance of provisional crowns fabricated with various techniques, and different thickness remains unknown. Thus, this in-vitro study aimed to evaluate the influence of restoration thickness and aging on the fracture behavior of provisional crowns fabricated using different techniques. Methods A dentiform maxillary first molar was prepared using a highly filled epoxy resin material to construct identical die replicas. Four groups of provisional crowns were fabricated: Group 1 was milled at 1.5 mm occlusal thickness; Group 2 was milled at 0.9 mm thickness; Group 3 was 3D-printed at 1.5 mm occlusal thickness; and Group 4 was 3D-printed at 0.9 mm occlusal thickness. Eight crowns from each group were subjected to a thermocycling process for 5000 cycles between baths held at 5 °C and 55 °C with a dwell time of 30 s and transfer time of 5 s. All crowns (aged and non-aged (control)) were loaded for fracturing using a universal testing machine at a 0.5 mm/min crosshead speed. Data were analyzed using a two-way analysis of variance and multiple comparisons at (α = 0.05). Results The maximum mean force load was found in the non-aged milled group (M1.5) at 1706.36 ± 124.07 N; the minimum mean force load was recorded for the aged 3D-printed group (3D0.9) at 552.49 ± 173.46 N. A significant difference was observed before and after thermocycling (p < 0.01). Conclusion Computer-aided design and manufacture of milled provisional crowns is superior to 3D-printed crowns for fracture resistance.
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Affiliation(s)
- Majed M. Alsarani
- Dental Health Department, College of Applied Medical Sciences, King Saud University, KSU, Building 24, Office: 2201, Riyadh 12372, Saudi Arabia
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Rahmatian M, Jafari Z, Moghaddam KN, Dianat O, Kazemi A. Finite Element Analysis of Fracture Resistance of Mandibular Molars with Different Access Cavity Designs. J Endod 2023; 49:1690-1697. [PMID: 37804945 DOI: 10.1016/j.joen.2023.09.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2023] [Revised: 09/28/2023] [Accepted: 09/29/2023] [Indexed: 10/09/2023]
Abstract
INTRODUCTION This study aimed to assess the fracture resistance of mandibular first molars after preparation with 3 different access cavity designs and 2 rotary systems using finite element analysis. METHODS Six 3-dimensionally printed mandibular first molars simulating natural teeth received traditional, conservative, and ultraconservative (truss) access cavity preparations. The root canals in each group were instrumented with either XP-Endo Shaper (FKG Dentaire, La Chaux-de-Fonds, Switzerland) or TruNatomy (Dentsply Sirona, Ballaigues, Switzerland) rotary files. The models were individually digitized, and micro-computed tomographic scans were transferred to Mimics software (Materialise NV, Leuven, Belgium) to create a geometric model of the tooth. The designed model was exported to 3-matic software (Materialise NV), and STL files were transferred to Geomagic Design X (3D Systems, Rock Hill, SC). Point cloud data were used for surfacing and transferred to ANSYS software (Ansys, Canonsburg, PA). A 200-N superficial force was applied vertically to the buccal cusps and central fossa, and the maximum and minimum equivalent von Mises stress values were calculated and reported. RESULTS The traditional and ultraconservative access cavity designs yielded the highest and the lowest von Mises stress values, respectively. In the ultraconservative cavity design, the stress values in pericervical dentin were lower in canal preparation with TruNatomy compared with XP-Endo Shaper. In the traditional and conservative cavity designs, stress was lower in the first 2 mm from the cementoenamel junction in the XP-Endo Shaper group and in the next 3 mm in the TruNatomy group. CONCLUSIONS Stress was lower in the ultraconservative and conservative cavity designs compared with the traditional design. Also, root canal preparation with TruNatomy yielded lower stress values in general compared with XP-Endo Shaper.
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Affiliation(s)
| | - Zahra Jafari
- Department of Endodontics, Dental School, Shahed University, Tehran, Iran
| | | | - Omid Dianat
- Endodontic Division, Department of Advanced Oral Sciences and Therapeutics, University of Maryland School of Dentistry, Baltimore, Maryland
| | - Ali Kazemi
- Department of Endodontics, Dental School, Shahed University, Tehran, Iran.
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Tribst JPM, Tach Q, de Kok P, Dal Piva AMDO, Kuijs RH, Kleverlaan CJ. Thickness and Substrate Effect on the Mechanical Behaviour of Direct Occlusal Veneers. Int Dent J 2023; 73:612-619. [PMID: 36509557 PMCID: PMC10509395 DOI: 10.1016/j.identj.2022.11.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2022] [Accepted: 11/09/2022] [Indexed: 12/13/2022] Open
Abstract
PURPOSE This study aimed to evaluate the fracture resistance and stress magnitude of occlusal veneers made of conventional or flowable resin composites at different minimal thicknesses bonded on enamel or dentin. MATERIAL AND METHODS A total of 120 sound bovine incisors were flattened and used as substrates (enamel or dentin) for the restorations. The teeth were embedded into polymethyl methacrylate and allocated into 4 groups according to the resin composite (Clearfil AP-X PLT and Clearfil Majesty Flow, Kuraray Dental) and substrate. Further, the substrates were randomly subdivided in 12 groups (N = 120, n = 10) according to the occlusal veneer minimal thickness: 0.5, 1.0, or 2.0 mm. The teeth were directly restored with a standardised procedure. Then, the specimens were loaded until fracture in a universal testing machine (Instron 6022, Instron Corp.). A 3-way and a 1-way analysis of variance were used to determine significant differences for each factor. Three-dimensional finite element analysis was carried out following the in vitro boundary conditions to assess the stress magnitude in the restoration during compressive loading. RESULTS The fracture loads were recorded into initial load to failure (ILF) and fatal load to failure (FLF). Differences were found in material for ILF and FLF, leading to an overall equal good performance in fracture load and stress distribution for both materials, regardless of the substrate. Differences in thickness were apparent in both ILF and FLF. CONCLUSIONS Direct conventional and flow resin composite occlusal veneers present a promising mechanical behaviour when bonded on enamel or dentin. However, caution is advised when preparing 0.5-mm minimal thickness restorations.
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Affiliation(s)
- João Paulo M Tribst
- Department of Oral Regenerative Medicine, Academic Centre for Dentistry Amsterdam (ACTA), Universiteit van Amsterdam and Vrije Universiteit, Amsterdam, The Netherlands
| | - Qais Tach
- Department of Dental Materials Science, Academic Centre for Dentistry Amsterdam (ACTA), Universiteit van Amsterdam and Vrije Universiteit, Amsterdam, The Netherlands; Private practice, Rotterdam, The Netherlands
| | - Paul de Kok
- Department of Dental Materials Science, Academic Centre for Dentistry Amsterdam (ACTA), Universiteit van Amsterdam and Vrije Universiteit, Amsterdam, The Netherlands
| | - Amanda Maria de O Dal Piva
- Department of Dental Materials Science, Academic Centre for Dentistry Amsterdam (ACTA), Universiteit van Amsterdam and Vrije Universiteit, Amsterdam, The Netherlands.
| | - Ruud H Kuijs
- Department of Oral Regenerative Medicine, Academic Centre for Dentistry Amsterdam (ACTA), Universiteit van Amsterdam and Vrije Universiteit, Amsterdam, The Netherlands
| | - Cornelis J Kleverlaan
- Department of Dental Materials Science, Academic Centre for Dentistry Amsterdam (ACTA), Universiteit van Amsterdam and Vrije Universiteit, Amsterdam, The Netherlands
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Mangoush E, Garoushi S, Vallittu P, Lassila L. Load-bearing capacity and wear characteristics of short fiber-reinforced composite and glass ceramic fixed partial dentures. Eur J Oral Sci 2023; 131:e12951. [PMID: 37641165 DOI: 10.1111/eos.12951] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2023] [Accepted: 08/15/2023] [Indexed: 08/31/2023]
Abstract
The aim of this study was to evaluate load-bearing capacity and wear performance of experimental short fiber-reinforced composite (SFRC) and conventional lithium-disilicate CAD/CAM fabricated fixed partial dentures (FPDs). Two groups (n = 12/group) of three-unit CAD/CAM fabricated posterior FPDs were made. The first group used experimental SFRC blocks, and the second group fabricated from lithium-disilicate (IPS e.max CAD). All FPDs were luted on a zirconia testing jig with dual-curing resin cement. Half of FPDs per group were quasi-statically loaded until fracture. The other half experienced cyclic fatigue aging (100.000 cycles, Fmax = 500 N) before loading quasi-statically until fracture. Fracture mode was examined using SEM. Wear test was performed using 15,000 loading cycles. Both material type and aging had a significant effect on the load-bearing capacity of FPDs. Experimental SFRC CAD without fatigue aging had significantly the highest load-bearing capacity (2096 ± 149N). Cyclic fatigue aging decreased the load-bearing capacity of the SFRC group (1709 ± 188N) but increased it for the lithium-disilicate group (1546 ± 155N). Wear depth values of SFRC CAD (29.3μm) were significantly lower compared to lithium-disilicate (54.2μm). Experimental SFRC CAD demonstrated the highest load-bearing capacity before and after cyclic fatigue aging, and superior wear behavior compared to the control material.
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Affiliation(s)
- Enas Mangoush
- Department of Biomaterials Science and Turku Clinical Biomaterial Center -TCBC, Institute of Dentistry, University of Turku, Turku, Finland
| | - Sufyan Garoushi
- Department of Biomaterials Science and Turku Clinical Biomaterial Center -TCBC, Institute of Dentistry, University of Turku, Turku, Finland
| | - Pekka Vallittu
- Department of Biomaterials Science and Turku Clinical Biomaterial Center -TCBC, Institute of Dentistry, University of Turku, Turku, Finland
- Wellbeing Services County of South-West Finland, Turku, Finland
| | - Lippo Lassila
- Department of Biomaterials Science and Turku Clinical Biomaterial Center -TCBC, Institute of Dentistry, University of Turku, Turku, Finland
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19
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Hofsteenge JW, Carvalho MA, Borghans PM, Cune MS, Özcan M, Magne P, Gresnigt MMM. Effect of preparation design on fracture strength of compromised molars restored with lithium disilicate inlay and overlay restorations: An in vitro and in silico study. J Mech Behav Biomed Mater 2023; 146:106096. [PMID: 37659167 DOI: 10.1016/j.jmbbm.2023.106096] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2023] [Revised: 08/24/2023] [Accepted: 08/28/2023] [Indexed: 09/04/2023]
Abstract
PURPOSE The objective of this study was to determine the influence of different preparation designs on the fracture strength, failure type, repairability, formation of polymerization-induced cracks, and tooth deformation of structurally compromised molars restored with lithium disilicate inlays and overlays in combination with Immediate Dentin Sealing (IDS). MATERIAL AND METHODS Human molars (N = 64) were randomly assigned to four different preparation designs: Undermined Inlay (UI), Extended Inlay (EI), Restricted Overlay (RO), and Extended Overlay (EO). The teeth were restored using lithium disilicate partial restorations and subjected to thermomechanical fatigue in a chewing simulator (1,2 × 10 (Mondelli et al., 2007) cycles on 50 N, 8000x 5-55 °C), followed by load to failure testing. In silico finite element analysis was conducted to assess tooth deformation. Polymerization-induced cracks were evaluated using optical microscopy and transillumination. Fracture strengths were statistically analyzed using a Kruskal-Wallis test, while the failure mode, repairability, and polymerization cracks were analyzed using Fisher exact test. RESULTS The propagation of polymerization-induced cracks did not significantly differ among preparation designs. All specimens withstood chewing simulator fatigue, with no visible cracks in teeth or restorations. Fracture strength was significantly influenced by preparation design, with restricted overlay (RO) showing higher fracture strength compared to extended inlay (EI) (p = .042). Tooth deformation and fracture resistance correlated between in vitro and in silico analyses). UI exhibited a statistically less destructive failure pattern than EO (p < .01) and RO (p = .036). No statistically significant influence of the preparation design on repairability was observed. Groups with higher repairability rates experienced increased tooth deformation, leading to less catastrophic failures. CONCLUSIONS The preparation design affected the fracture strength of compromised molars restored with lithium disilicate inlays and overlays, with significantly lower fracture strength for an extended inlay. The failure pattern of lithium disilicate overlays is significantly more destructive than that of undermined and extended inlays. The finite element analysis showed more tooth deformation in the inlay restorations, with lower forces in the roots, leading to less destructive fractures. Since cusp coverage restorations fracture in a more destructive manner, this study suggests the undermined inlay preparation design as a viable option for restoring weakened cusps.
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Affiliation(s)
- Jelte W Hofsteenge
- University of Groningen, University Medical Center Groningen, Center for Dentistry and Oral Hygiene, Department of Restorative Dentistry, Groningen, the Netherlands.
| | | | - Pauline M Borghans
- University of Groningen, University Medical Center Groningen, Center for Dentistry and Oral Hygiene, Department of Restorative Dentistry, Groningen, the Netherlands
| | - Marco S Cune
- University of Groningen, University Medical Center Groningen, Center for Dentistry and Oral Hygiene, Department of Restorative Dentistry, Groningen, the Netherlands; St. Antonius Hospital Nieuwegein, Department of Oral-Maxillofacial Surgery, Prosthodontics and Special Dental Care, Nieuwegein, the Netherlands
| | - Mutlu Özcan
- University of Groningen, University Medical Center Groningen, Center for Dentistry and Oral Hygiene, Department of Restorative Dentistry, Groningen, the Netherlands; University of Zurich, Center of Dental Medicine, Division of Dental Biomaterials, Clinic for Reconstructive Dentistry, Zurich, Switzerland
| | - Pascal Magne
- Center for Education and Research in Biomimetic Restorative Dentistry (CER BRD), Beverly Hills, CA, USA
| | - Marco M M Gresnigt
- University of Groningen, University Medical Center Groningen, Center for Dentistry and Oral Hygiene, Department of Restorative Dentistry, Groningen, the Netherlands; Martini Hospital, Department of Special Dental Care, Groningen, the Netherlands
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20
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Veselinova M, Diamantopoulou S, Paximada C, Papazoglou E. In-Vitro Comparison of Fracture Strength of Endocrowns and Overlays in Endodontically Treated Teeth Manufactured with Monolithic Lithium Disilicate and Zirconia. J Funct Biomater 2023; 14:422. [PMID: 37623666 PMCID: PMC10455451 DOI: 10.3390/jfb14080422] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2023] [Revised: 07/25/2023] [Accepted: 08/08/2023] [Indexed: 08/26/2023] Open
Abstract
To evaluate the fracture strength and the failure mode of endodontically treated molars restored with monolithic lithium disilicate and zirconia endocrowns and overlays. A total of 48 extracted mandibular molars were endodontically treated, decoronated 2 mm above the cementoenamel junction and divided into four 12-specimen groups. Group ELD: lithium disilicate endocrowns. Group EZ: monolithic zirconia endocrowns. Group OLD: lithium disilicate overlays. Group OZ: monolithic zirconia overlays. Overlays did not extend in the pulp chamber and endocrowns extended in the pulp chamber 2 mm. After adhesive bonding of the restorations, the specimens were subjected to thermocycling (×5000 cycles) and then to fracture resistance testing at lateral static loading (1 mm/min) at a universal testing machine. The failure mode of the specimens was qualitatively evaluated. Differences in means were compared using with t-tests for independent samples or Mann-Whitney test (p < 0.05). Weibull distribution analysis was also performed. Group ELD showed significantly higher fracture strength than all other groups (p = 0.001), and the highest Weibull modulus. Conclusions: Lithium disilicate endocrowns exhibit higher fracture strength and are more reliable compared to the other types of restorations examined. Endocrowns had more catastrophic failures compared to overlays.
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Affiliation(s)
| | | | | | - Efstratios Papazoglou
- Department of Operative Dentistry, National and Kapodistrian University of Athens, 11527 Athens, Greece; (M.V.); (S.D.); (C.P.)
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21
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Martins WF, Coelho CSS, Amaral FLBD, França FMG, Turssi CP, Cavalli V, Basting RT. Fracture load and failure mode of semi-direct resin composite occlusal veneers: Influence of design and mechanical cycling. J Mech Behav Biomed Mater 2023; 144:105961. [PMID: 37320893 DOI: 10.1016/j.jmbbm.2023.105961] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2023] [Revised: 06/05/2023] [Accepted: 06/06/2023] [Indexed: 06/17/2023]
Abstract
AIMS To evaluate the influence of the type of preparation and mechanical cycling on the fracture load and failure mode of semi-direct posterior resin composite restorations. METHODS In total, 70 healthy third molars were used; 10 belonging to the control group (C - unprepared teeth) and 60 teeth prepared and restored with nanoparticle resin composite, divided into 3 groups (n = 20): O - exclusively occlusal preparation (Table Top); OV - occlusal preparation with buccal extension (Veneerlay); OVP - Occlusal preparation with chamfer on the proximal and buccal-lingual/palatal surfaces (Overlay). The preparations were performed with diamond burs with a thickness of 1 mm. The restorations were made with nanoparticulate resin composite (Filtek Z350 XT) and subsequently received additional polymerization (thermoprocessing). Cementation was performed with the use of universal adhesive system (Single Bond Universal) on dental substrate and dual resin cement (RelyX ARC). Half of the teeth in each group (n = 10) were submitted to mechanical cycling, simulating 6 months of clinical service (5 × 105 fatigue cycles), under dynamic loading of 130 N, at a frequency of 2Hz. Fracture load tests were performed in a universal testing machine with a 200 kgf load cell. Failure mode was classified using scores. Generalized linear models and Fisher Exact tests were applied to the data (significance level of 5%). RESULTS There were no significant differences between the types of preparation (p = 0.9435), or relative to cycling (p = 0.3764). The Fisher Exact Test showed a significant association between the groups and the type of failure (p = 0.0006), with preparations O (with cycling) and OVP (with and without cycling) exhibiting most failures with restoration fractures without involvement of the dental remnant. CONCLUSIONS Semi-direct restorations showed resistance to fracture load similar to that of healthy teeth and were capable of withstanding functional masticatory loads. The type of preparation influenced the failure mode of teeth. The Table Top and Overlay types of preparations were those had fewer catastrophic failures, suggesting that since they are more conservative preparations, they made it possible for the tooth to receive a new restorative procedure in the future in cases of failures.
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Affiliation(s)
- Wellington Ferreira Martins
- Faculdade São Leopoldo Mandic, Rua José Rocha Junqueira 13, Bairro Swift, Campinas, CEP: 13045-755, São Paulo, Brazil.
| | - Camila Siqueira Silva Coelho
- Piracicaba Dental School, University of Campinas, 901 Limeira Avenue, Areião, 13414-903, Piracicaba, São Paulo, Brazil.
| | | | | | - Cecilia Pedroso Turssi
- Faculdade São Leopoldo Mandic, Rua José Rocha Junqueira 13, Bairro Swift, Campinas, CEP: 13045-755, São Paulo, Brazil.
| | - Vanessa Cavalli
- Piracicaba Dental School, University of Campinas, 901 Limeira Avenue, Areião, 13414-903, Piracicaba, São Paulo, Brazil.
| | - Roberta Tarkany Basting
- Faculdade São Leopoldo Mandic, Rua José Rocha Junqueira 13, Bairro Swift, Campinas, CEP: 13045-755, São Paulo, Brazil.
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22
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Teegen IS, Schadte P, Wille S, Adelung R, Siebert L, Kern M. Comparison of properties and cost efficiency of zirconia processed by DIW printing, casting and CAD/CAM-milling. Dent Mater 2023; 39:669-676. [PMID: 37230861 DOI: 10.1016/j.dental.2023.05.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2022] [Revised: 04/27/2023] [Accepted: 05/02/2023] [Indexed: 05/27/2023]
Abstract
OBJECTIVES The aim of this study was to evaluate the mechanical properties and cost efficiency of direct ink writing (DIW) printing of two different zirconia inks compared to casting and subtractive manufacturing. METHODS Zirconia disks were manufactured by DIW printing and the casting process and divided into six subgroups (n = 20) according to sintering temperatures (1350 °C, 1450 °C and 1550 °C) and two different ink compositions (Ink 1, Ink 2). A CAD/CAM-milled high strength zirconia (3Y-TZP) was added as reference group. The biaxial flexural strength (BFS) was measured using the piston-on-three-balls test. X-ray-diffraction (XRD) was used for microstructural analysis. The cost efficiency was compared for DIW printing and subtractive manufacturing by calculation of the manufacturing costs of one dental crown. RESULTS Using XRD, monoclinic and tetragonal phases were detected for Ink 1, for all other groups no monoclinic phase was detected. The CAD/CAM-milled ceramic showed a significantly higher BFS than all other groups. The BFS of Ink 2 was significantly higher than the BFS of Ink 1. At a sintering temperature of 1550 °C the mean BFS of the printed Ink 2 was 822 ± 174 MPa. The BFS of the cast materials did not show a significantly higher BFS than the corresponding printed group for any tested parameter-set. The manufacturing costs of DIW printed crowns are lower than the manufacturing costs of CAD/CAM-milled crowns. CONCLUSION DIW has a high potential to replace subtractive processes for dental applications, as it shows promising mechanical properties for appropriate ink compositions and facilitates a highly cost effective production.
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Affiliation(s)
- Isabell-Sophie Teegen
- Department of Prosthodontics, Propaedeutics and Dental Materials, School of Dentistry, Kiel University, Arnold-Heller-Straße 16, 24105 Kiel, Germany.
| | - Philipp Schadte
- Department of Material Science, Faculty of Engineering, Kiel University, Kaiserstr. 2, 24143 Kiel, Germany.
| | - Sebastian Wille
- Department of Prosthodontics, Propaedeutics and Dental Materials, School of Dentistry, Kiel University, Arnold-Heller-Straße 16, 24105 Kiel, Germany.
| | - Rainer Adelung
- Department of Material Science, Faculty of Engineering, Kiel University, Kaiserstr. 2, 24143 Kiel, Germany.
| | - Leonard Siebert
- Department of Material Science, Faculty of Engineering, Kiel University, Kaiserstr. 2, 24143 Kiel, Germany.
| | - Matthias Kern
- Department of Prosthodontics, Propaedeutics and Dental Materials, School of Dentistry, Kiel University, Arnold-Heller-Straße 16, 24105 Kiel, Germany.
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23
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Abad-Coronel C, Calle C, Abril G, Paltán CA, Fajardo JI. Fracture Resistance Analysis of CAD/CAM Interim Fixed Prosthodontic Materials: PMMA, Graphene, Acetal Resin and Polysulfone. Polymers (Basel) 2023; 15:polym15071761. [PMID: 37050375 PMCID: PMC10097223 DOI: 10.3390/polym15071761] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2023] [Revised: 03/20/2023] [Accepted: 03/21/2023] [Indexed: 04/05/2023] Open
Abstract
The aim of this study was to evaluate and compare the fracture resistance of temporary restorations made of polymethylmethacrylate (PMMA), graphene-modified PMMA (GRA), acetal resin (AR) and polysulfone (PS) obtained by a subtractive technique (milling) using a computer-aided design and manufacturing (CAD/CAM) system of a three-unit fixed dental prosthesis (FDP). Methods: Four groups of ten samples were fabricated for each material. Each specimen was characterized by a compression test on a universal testing machine, all specimens were loaded to fracture and the value in Newtons (N) was recorded by software connected to the testing machine. The fracture mode was evaluated on all samples using a stereomicroscope. Results: There were statistically significant differences (p value < 0.005) between PMMA and the other three materials (PMMA: 1302.71 N; GRA: 1990.02 N; RA: 1796.20 N; PS: 2234.97). PMMA presented a significantly lower value than the other materials, and PS showed the highest value. GRA and RA presented a similar range of values but they were still higher than those of PMMA. Conclusions: GRA, RA and PS are presented as valid options within the range of interim milled restorative materials and as alternatives to PMMA.
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Affiliation(s)
- Cristian Abad-Coronel
- CAD/CAM Materials and Digital Dentistry Research Group, Faculty of Dentistry, Universidad de Cuenca, Cuenca 010107, Ecuador
| | - Carolina Calle
- Faculty of Dentistry, Universidad de Cuenca, Cuenca 010101, Ecuador
| | - Gabriela Abril
- Faculty of Dentistry, Universidad de Cuenca, Cuenca 010101, Ecuador
| | - César A. Paltán
- New Materials and Transformation Processes Research Group GiMaT, Universidad Politécnica Salesiana, Cuenca 170517, Ecuador
| | - Jorge I. Fajardo
- Mechanical Enginnering Faculty, Universidad Politécnica Salesiana, Cuenca 170517, Ecuador
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24
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Ille C, Moacă EA, Pop D, Goguță L, Opriș C, Pîrvulescu IL, Avram L, Faur A, Jivănescu A. Compressive strength evaluation of thin occlusal veneers from different CAD/CAM materials, before and after acidic saliva exposure. Odontology 2023; 111:360-374. [PMID: 36097129 PMCID: PMC10020293 DOI: 10.1007/s10266-022-00741-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2022] [Accepted: 09/02/2022] [Indexed: 01/09/2023]
Abstract
In the present study are depicted valuable observations for practitioners, obtained from an in vitro study which aims to evaluate the compressive strength of occlusal veneers fabricated from 3 type of restorative materials, before and after 1 month of acidic artificial saliva exposure (pH = 2.939). In this context, 90 extracted human molars were prepared to receive computer-aided design/computer-aided manufacturing (CAD/CAM) occlusal veneers. The restorative materials considered in this study were: Cerasmart; Straumann Nice and Tetric CAD. The occlusal veneers were designed, milled and cemented with an adhesive dual-cure resin cement. From all the extracted human molars, only sixty specimens were immersed in acidic artificial saliva, for 1 month, at 37 °C ± 1 °C and part of this specimens were also thermo-cycled, between 5 and 55 °C ± 2 °C, before compressive strength test. The results showed a lower compressive strength for both the samples exposed to acidic artificial saliva as well as for the samples exposed to acidic artificial saliva and thermo-cycled. Scanning electron microscopy (SEM) showed that after compressive strength, all the specimens non-exposed to acidic artificial saliva, present extensive cracks formation at the surface of the restorations, and after exposure to acidic artificial saliva for 1 month, the surface damage was characterized by longitudinal and profound fractures of the restoration, as well as the fracture of the tooth structure. Between CAD/CAM materials tested, nanoceramic resin shows more favorable fracture patterns, both before and after acidic artificial saliva exposure.
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Affiliation(s)
- Codruța Ille
- Department of Prosthodontics, Faculty of Dental Medicine, “Victor Babes” University of Medicine and Pharmacy, Revolutiei Ave. 1989, No. 9, 300580 Timișoara, Romania
- TADERP Research Center—Advanced and Digital Techniques for Endodontic, Restorative and Prosthetic Treatment, “Victor Babeș” University of Medicine and Pharmacy, Revolutiei Ave. 1989, No. 9, 300041 Timişoara, Romania
| | - Elena-Alina Moacă
- Department of Toxicology and Drug Industry, Faculty of Pharmacy, “Victor Babeș” University of Medicine and Pharmacy Timisoara, 2nd Eftimie Murgu Square, 300041 Timisoara, Romania
- Research Centre for Pharmaco-Toxicological Evaluation, “Victor Babeș” University of Medicine and Pharmacy, 2nd Eftimie Murgu Square, 300041 Timișoara, Romania
| | - Daniel Pop
- Department of Prosthodontics, Faculty of Dental Medicine, “Victor Babes” University of Medicine and Pharmacy, Revolutiei Ave. 1989, No. 9, 300580 Timișoara, Romania
- TADERP Research Center—Advanced and Digital Techniques for Endodontic, Restorative and Prosthetic Treatment, “Victor Babeș” University of Medicine and Pharmacy, Revolutiei Ave. 1989, No. 9, 300041 Timişoara, Romania
| | - Luciana Goguță
- Department of Prosthodontics, Faculty of Dental Medicine, “Victor Babes” University of Medicine and Pharmacy, Revolutiei Ave. 1989, No. 9, 300580 Timișoara, Romania
| | - Carmen Opriș
- Department for Materials and Manufacturing Engineering, Faculty of Mechanics, Politechnic University of Timisoara, Mihai Viteazu Ave., No. 1, 300222 Timisoara, Romania
| | - Ioana Ligia Pîrvulescu
- Department of Prosthodontics, Faculty of Dental Medicine, “Victor Babes” University of Medicine and Pharmacy, Revolutiei Ave. 1989, No. 9, 300580 Timișoara, Romania
| | - Liane Avram
- Department of Prosthodontics, Faculty of Dental Medicine, “Victor Babes” University of Medicine and Pharmacy, Revolutiei Ave. 1989, No. 9, 300580 Timișoara, Romania
| | - Andrei Faur
- Department of Prosthodontics, Faculty of Dental Medicine, “Victor Babes” University of Medicine and Pharmacy, Revolutiei Ave. 1989, No. 9, 300580 Timișoara, Romania
| | - Anca Jivănescu
- Department of Prosthodontics, Faculty of Dental Medicine, “Victor Babes” University of Medicine and Pharmacy, Revolutiei Ave. 1989, No. 9, 300580 Timișoara, Romania
- TADERP Research Center—Advanced and Digital Techniques for Endodontic, Restorative and Prosthetic Treatment, “Victor Babeș” University of Medicine and Pharmacy, Revolutiei Ave. 1989, No. 9, 300041 Timişoara, Romania
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25
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Alhamoudi FH, Aldosari LIN, Alshadidi AAF, Hassan SAB, Alwadi MAM, Vaddamanu SK, Cicciù M, Minervini G. An Investigation of the Fracture Loads Involved in the Framework of Removable Partial Dentures Using Two Types of All-Ceramic Restorations. Biomimetics (Basel) 2023; 8:biomimetics8010113. [PMID: 36975343 PMCID: PMC10046878 DOI: 10.3390/biomimetics8010113] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2023] [Revised: 02/21/2023] [Accepted: 03/06/2023] [Indexed: 03/12/2023] Open
Abstract
Retention and support are needed for removable partial denture stability. The stability can be achieved by clasps, occlusal and cingulum rests on healthy abutment teeth. However, implants or crowns can be used to support the removable partial denture instated on unhealthy abutment teeth. This study was conducted to investigate the fracture strength of two types of all-ceramic restorations used as abutments for the removable partial denture framework. The crowns were manufactured with two types of ceramic materials: zirconia and IPS e.max Press ceramics. The metal alloy (cobalt-chrome) was cast to form the removable partial denture framework. A universal testing machine was used to evaluate the fracture strength of both ceramic crown materials. The results presented no fractures in all-ceramic crowns, but deformation of the partial denture frameworks occurred. With the limitation of this study, it can be concluded that zirconia and IPS e.max Press ceramic can be used as abutments to provide adequate support to the removable partial denture.
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Affiliation(s)
- Fahad Hussain Alhamoudi
- Dental Technology Department, College of Applied Medical Science, King Khalid University, Abha 61421, Saudi Arabia
- Correspondence: (F.H.A.); (S.K.V.); (G.M.)
| | - Lujain Ibrahim N. Aldosari
- Department of Prosthetic Dentistry, College of Dentistry, King Khalid University, Abha 61421, Saudi Arabia
| | - Abdulkhaliq Ali F. Alshadidi
- Dental Technology Department, College of Applied Medical Science, King Khalid University, Abha 61421, Saudi Arabia
| | - Saeed Awod Bin Hassan
- Department of Restorative Dental Sciences, College of Dentistry, King Khalid University, Abha 61421, Saudi Arabia
| | - Maram Ali M. Alwadi
- Dental Health Department, College of Applied Medical Science, King Saud University, Riyadh 11451, Saudi Arabia
| | - Sunil Kumar Vaddamanu
- Dental Technology Department, College of Applied Medical Science, King Khalid University, Abha 61421, Saudi Arabia
- Correspondence: (F.H.A.); (S.K.V.); (G.M.)
| | - Marco Cicciù
- Department of General Surgery and Medical-Surgical Specialties, School of Dentistry, University of Catania, 95124 Catania, Italy
| | - Giuseppe Minervini
- Multidisciplinary Department of Medical-Surgical and Odontostomatological Specialties, University of Campania “Luigi Vanvitelli”, 80121 Naples, Italy
- Correspondence: (F.H.A.); (S.K.V.); (G.M.)
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26
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Influence of thermo-mechanical aging on fracture resistance and wear of digitally standardized chairside computer-aided-designed/computer-assisted-manufactured restorations. J Dent 2023; 130:104450. [PMID: 36773741 DOI: 10.1016/j.jdent.2023.104450] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2022] [Revised: 01/24/2023] [Accepted: 02/08/2023] [Indexed: 02/11/2023] Open
Abstract
OBJECTIVES To investigate the influence of thermal cycling and mechanical loading (TCML) aging on fracture resistance and wear behavior of various chairside computer-aided-designed/computer-assisted-manufactured (CAD/CAM) premolar crowns cemented on standardized tooth abutments. METHODS Eighty chairside CAD/CAM crowns were prepared using lithium disilicate (IPS e.max CAD; EM), zirconia-infiltrated lithium silicate (Celtra Duo; CD), polymer-infiltrated ceramic network (Vita Enamic; VE), and resin nanoceramics (Cerasmart; CS) (n = 20). The specimens were divided into two groups (n = 10). In one group, they were subjected to TCML: thermocycling (6000 cycles in distilled water at 5-55 °C) and mechanical loading (50 N for 1.2 × 106 cycles), while in control group they were stored in distilled water (37 °C for 24 h). The fracture load, height loss, and volume wear of the crowns were measured after TCML. Fractography was performed on fractured specimens. Data were analyzed using analysis of variance and multiple comparison tests (α=0.05). RESULTS The mean fracture loads of EM and CD were significantly higher than those of EC and CS (p<0.05). There was no significant change in the fracture load of any CAD/CAM crowns after TCML (p>0.05). CS exhibited a significantly higher volume wear than the other materials investigated. The wear tracts of all TCML crowns acted as failure origins during the fracture test. CONCLUSIONS The fracture resistance of glass-ceramic CAD/CAM crowns was significantly higher than that of resin composite crowns. A 5-year TCML aging did not affect the fracture resistance of CAD/CAM crowns investigated. However, TCML treatment produces a larger wear track in CS than in other materials. CLINICAL SIGNIFICANCE Appropriate chairside CAD/CAM restorative material should be selected for successful clinical practice after considering the fracture and wear resistance of the crowns.
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27
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Lan TH, Fok ASL, Hung CC, Du JK, Liu CT, Chen JH. Stress analysis and risk of failure during clenching in ceramic assembly models: 3-dimensional finite element analysis. J Dent Sci 2023; 18:791-800. [PMID: 37021211 PMCID: PMC10068548 DOI: 10.1016/j.jds.2023.01.015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2022] [Revised: 01/18/2023] [Indexed: 02/04/2023] Open
Abstract
Background/purpose Clenching is a dental parafunctional disorder that jeopardizes the life of teeth and/or dental prostheses. Computer-aided design and computer-aided manufacturing (CAD/CAM)-fabricated or 3-dimensional-printed dental prostheses are aesthetic, strong, and of good quality, but noticeable damage can still be observed after clenching. Stress analysis of synthetic ceramic assemblies with various parameters was conducted to provide data that may be used to improve the fabrication of CAD/CAM-fabricated dental prostheses. Materials and methods Abaqus software was used to run the simulations. A total of 96 axisymmetric finite element ceramic assembly models were simulated under 800 N vertical loading and different contact radii (0.25, 0.5, 0.75, 1.0 mm), materials (IPS e.max CAD and Vita Enamic), layer thicknesses and combinations. Results Four-layered ceramic assembly models produced promising results with the following parameters: contact radius of at least 0.5 mm, total thickness of at least 0.5 mm, and use of IPS e.max CAD as the first layer and Vita Enamic as the second layer without cement. Conclusion The ideal four-layered assembly model design uses 0.25-mm-thick IPS e.max CAD as its outer layer to simulate enamel binding and 0.25-mm-thick Vita Enamic as its inner layer to imitate the natural tooth. This design may be used as reference for prosthodontic treatment.
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Affiliation(s)
- Ting-Hsun Lan
- Division of Prosthodontics, Department of Dentistry, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan
- School of Dentistry, College of Dental Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan
- Corresponding author. School of Dentistry, College of Dental Medicine, Kaohsiung Medical University, 100 Shin-Chuan 1st Road, Sanmin District, Kaohsiung 807378, Taiwan.
| | - Alex Siu Lun Fok
- Minnesota Dental Research Center for Biomaterials and Biomechanics, University of Minnesota, Minneapolis, MN, USA
- Corresponding author. Minnesota Dental Research Center for Biomaterials and Biomechanics, University of Minnesota, Minneapolis, 16-212 Moos Tower 515 Delaware St. SE Minneapolis, MN, 55455, USA.
| | - Chun-Cheng Hung
- Division of Prosthodontics, Department of Dentistry, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan
- School of Dentistry, College of Dental Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Je-Kang Du
- Division of Prosthodontics, Department of Dentistry, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan
- School of Dentistry, College of Dental Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Chih-Te Liu
- Division of Prosthodontics, Department of Dentistry, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan
| | - Jeh-Hao Chen
- Division of Prosthodontics, Department of Dentistry, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan
- School of Dentistry, College of Dental Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan
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Zhou T, Mirchandani B, Li XX, Mekcha P, Buranawat B. Quantitative parameters of digital occlusal analysis in dental implant supported restorative reconstruction recent 5 years: a systematic review. Acta Odontol Scand 2023; 81:1-17. [PMID: 35617455 DOI: 10.1080/00016357.2022.2077980] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
OBJECTIVE The aims of this systematic review were to evaluate the clinical masticatory performance of implant-supported restorations, observe the occlusal force changes in the distribution of the implant restoration and reveal the positive and negative contributing factors of implant design and components based on the outcomes of digital occlusal measurement. MATERIAL AND METHODS An extensive search was conducted through PubMed and CENTRAL to identify clinical trials on implant-retained restorations using digital occlusal analysis methods. Two researchers assessed the identified studies and data extraction independently, and the data synthesis strategies without meta-analysis that summarizes the effect estimates were adopted. RESULTS The search screened 3821 titles and abstracts, then full-text analysis for 26 articles was performed, and 14 studies were included in the quantitative synthesis. Four of six studies for implant-retained overdenture showed statistically significant improved bite force when immediate loading (p = .00045, .00005, .00055, and .00005, respectively), and no statistically significant results in the other two studies (p = .225, .371, respectively.) However, the results of the favoured intervention were not statistically significant (p = .104, .166, respectively) in two studies of single posterior implant restorations. In all three studies, the bite force distributed on the implant prostheses of partially fixed implant-retained restoration increased statistically significantly (p = .013, .001, .05, respectively). CONCLUSIONS The edentulous restoration supported by implants seems to significantly improves bite force and chewing efficiency compared with conventional dentures. Regular quantitative occlusal measurement is recommended to avoid the possible risk of overload. Smaller implants size and relatively small and flexible attachment designs may be more conducive to the stability and retention of the restoration of atrophy of alveolar bone.
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Affiliation(s)
- Ting Zhou
- Department of Orthodontics, School of Stomatology, Kunming Medical University, Yunnan, PR China.,Department of Periodontics and Implant Dentistry, Faculty of Dentistry, Thammasat University, Phatum Thani, Thailand
| | - Bharat Mirchandani
- Department of Periodontics and Implant Dentistry, Faculty of Dentistry, Thammasat University, Phatum Thani, Thailand
| | - Xing-Xing Li
- Department of Prosthodontics, School of Stomatology, Kunming Medical University, Yunnan, PR China
| | - Pichaya Mekcha
- Department of Periodontics and Implant Dentistry, Faculty of Dentistry, Thammasat University, Phatum Thani, Thailand
| | - Borvornwut Buranawat
- Department of Periodontics and Implant Dentistry, Faculty of Dentistry, Thammasat University, Phatum Thani, Thailand
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Spitznagel FA, Hoppe JS, Bonfante EA, Campos TMB, Langner R, Gierthmuehlen PC. Failure Load and Fatigue Behavior of Monolithic and Bi-Layer Zirconia Fixed Dental Prostheses Bonded to One-Piece Zirconia Implants. MATERIALS (BASEL, SWITZERLAND) 2022; 15:8465. [PMID: 36499960 PMCID: PMC9740162 DOI: 10.3390/ma15238465] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/27/2022] [Revised: 11/19/2022] [Accepted: 11/23/2022] [Indexed: 06/17/2023]
Abstract
No evidence-based prosthetic treatment concept for 3-unit fixed-dental-prostheses (FDPs) on ceramic implants is currently available. Therefore, the aim of this in vitro study was to investigate the failure load and fatigue behavior of monolithic and bi-layer zirconia FDPs supported by one-piece ceramic implants. Eighty 3-unit FDPs supported by 160 zirconia-implants (ceramic.implant; vitaclinical) were divided into 4 groups (n = 20 each): Group Z-HT: 3Y-TZP monolithic-zirconia (Vita-YZ-HT); Group Z-ST: 4Y-TZP monolithic-zirconia (Vita-YZ-ST); Group FL: 3Y-TZP zirconia (Vita-YZ-HT) with facial-veneer (Vita-VM9); Group RL (Rapid-layer): PICN “table-top” (Vita-Enamic), 3Y-TZP-framework (Vita-YZ-HT). Half of the test samples (n = 10/group) were fatigued in a mouth-motion chewing-simulator (F = 98 N, 1.2 million-cycles) with simultaneous thermocycling (5−55 °C). All specimens (fatigued and non-fatigued) were afterwards exposed to single-load-to-failure-testing (Z010, Zwick). Statistical analysis was performed using ANOVA, Tukey’s post-hoc tests and two-sample t-tests (p < 0.05, Bonferroni-corrected where appropriate). All specimens withstood fatigue application. While the effect of fatigue was not significant in any group (p = 0.714), the choice of material had a significant effect (p < 0.001). Material FL recorded the highest failure loads, followed by Z-ST, Z-HT and RL, both with and without fatigue application. Taken together, all tested FDP material combinations survived chewing forces that exceeded physiological levels. Bi-Layer FL and monolithic Z-ST showed the highest resilience and might serve as reliable prosthetic reconstruction concepts for 3-unit FDPs on ceramic implants.
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Affiliation(s)
- Frank A. Spitznagel
- Department of Prosthodontics, Medical Faculty and University Hospital Düsseldorf, Heinrich-Heine University, Moorenstraße 5, 40225 Düsseldorf, Germany
| | - Johanna S. Hoppe
- Department of Prosthodontics, Medical Faculty and University Hospital Düsseldorf, Heinrich-Heine University, Moorenstraße 5, 40225 Düsseldorf, Germany
| | - Estevam A. Bonfante
- Department of Prosthodontics and Periodontology; Bauru School of Dentistry, University of Sao Paulo, Bauru 17012-230, SP, Brazil
| | - Tiago M. B. Campos
- Department of Prosthodontics and Periodontology; Bauru School of Dentistry, University of Sao Paulo, Bauru 17012-230, SP, Brazil
| | - Robert Langner
- Institute of Systems Neuroscience, Medical Faculty, Heinrich-Heine-University, 40225 Düsseldorf, Germany
- Institute of Neuroscience and Medicine, Brain and Behavior (INM-7), Research Center Jülich, 52425 Jülich, Germany
| | - Petra C. Gierthmuehlen
- Department of Prosthodontics, Medical Faculty and University Hospital Düsseldorf, Heinrich-Heine University, Moorenstraße 5, 40225 Düsseldorf, Germany
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Dorado S, Arias A, Jimenez-Octavio JR. Biomechanical Modelling for Tooth Survival Studies: Mechanical Properties, Loads and Boundary Conditions-A Narrative Review. MATERIALS (BASEL, SWITZERLAND) 2022; 15:7852. [PMID: 36363451 PMCID: PMC9657341 DOI: 10.3390/ma15217852] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/10/2022] [Revised: 11/02/2022] [Accepted: 11/04/2022] [Indexed: 06/16/2023]
Abstract
Recent biomechanical studies have focused on studying the response of teeth before and after different treatments under functional and parafunctional loads. These studies often involve experimental and/or finite element analysis (FEA). Current loading and boundary conditions may not entirely represent the real condition of the tooth in clinical situations. The importance of homogenizing both sample characterization and boundary conditions definition for future dental biomechanical studies is highlighted. The mechanical properties of dental structural tissues are presented, along with the effect of functional and parafunctional loads and other environmental and biological parameters that may influence tooth survival. A range of values for Young's modulus, Poisson ratio, compressive strength, threshold stress intensity factor and fracture toughness are provided for enamel and dentin; as well as Young's modulus and Poisson ratio for the PDL, trabecular and cortical bone. Angles, loading magnitude and frequency are provided for functional and parafunctional loads. The environmental and physiological conditions (age, gender, tooth, humidity, etc.), that may influence tooth survival are also discussed. Oversimplifications of biomechanical models could end up in results that divert from the natural behavior of teeth. Experimental validation models with close-to-reality boundary conditions should be developed to compare the validity of simplified models.
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Affiliation(s)
- Saúl Dorado
- Department of Mechanical Engineering, Escuela Técnica Superior de Ingeniería ICAI, Universidad Pontificia Comillas, 28015 Madrid, Spain
| | - Ana Arias
- Department of Conservative and Prosthetic Dentistry, School of Dentistry, Complutense University, 28040 Madrid, Spain
| | - Jesus R. Jimenez-Octavio
- Instituto de Investigación Tecnológica, Escuela Técnica Superior de Ingeniería ICAI, Universidad Pontificia Comillas, 28015 Madrid, Spain
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Jockusch J, Hahnel S, Nitschke I. Use of handgrip strength measurement as an alternative for assessing chewing function in people with dementia. BMC Geriatr 2022; 22:769. [PMID: 36153477 PMCID: PMC9509657 DOI: 10.1186/s12877-022-03452-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2022] [Accepted: 09/14/2022] [Indexed: 11/12/2022] Open
Abstract
Background Chewing ability and handgrip strength can be independent explanatory factors of physical fitness. The usability of measurement procedures for assessing chewing function in people with dementia seems to be limited. This study aimed to show an association between handgrip strength and chewing function to enable the use of handgrip strength measurement as an alternative for determining chewing parameters in people with dementia. Methods The data analysed here are part of the OrBiD (Oral Health, Bite Force and Dementia) pilot study. A total of 120 participants were assigned to five evaluation groups based on their cognitive abilities using the Mini-Mental State Examination (MMSE). The MMSE groups in this data analysis were “no dementia” (noDem, MMSE 28–30), “mild cognitive impairment” (mCI, MMSE 25–27), and “mild dementia” (mDem, MMSE 18–24). Handgrip strength, maximum occlusal force, and chewing efficiency were measured. Results The Mini-Mental State Examination scores among all participants (n = 71) resulted in a median of 27 and a range of 18–30. An association between maximum handgrip strength and the cognitive impairment of the participants was shown. Nevertheless, the use of handgrip strength measurement as an alternative for determining chewing function was not verified in this study. Conclusions The feasibility and reliability of chewing function measurements in people with dementia should be investigated. Existing measurement procedures may need to be adapted or new assessments may need to be developed to be usable in people with dementia. Trial registration ClinicalTrials.gov NCT03775772.
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Chai H. On the evolution of the morphology and resilience of molar cusps in fossil hominid teeth. J Mech Behav Biomed Mater 2022; 133:105357. [PMID: 35841750 DOI: 10.1016/j.jmbbm.2022.105357] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2022] [Revised: 06/29/2022] [Accepted: 07/02/2022] [Indexed: 10/17/2022]
Abstract
Teeth play an important role in evolutionary studies due to their good preservation and direct link to diet. The present work makes use of a previously generated database on molar teeth of fossil hominids which consists of cuspal enamel thickness dc, dentin horn angle φ and section width D, all measured on a given histological tooth section. These data are here interpreted with the aid of "fracture stress" QF = PF/D2 and geological age t, where PF is the occlusal force needed to cause cusp failure as determined from dc and φ. QF is virtually a constant in non-hominins ("apes") while monotonically increasing toward present time in hominins. These two trends intersect at t = ts = 4.5 (0.11) mya, a value similar to other divergence estimates. QF was fitted with a function f(t) which is proportional to (dc/D)2. The monotonic variation of QF and in turn dc/D with t contrasts the more complex behavior generally characterizing other physical entities of fossil hominids. The increase in dc/D in hominins promotes tooth resilience and in turn life span. Finally, it is suggested that PF provides an upper bound to the maximum bite force produced by the jaw structure.
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Affiliation(s)
- Herzl Chai
- School of Mechanical Engineering, Tel-Aviv University, Israel.
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Kaur H, Singh N, Gupta H, Chakarvarty A, Sadana P, Gupta N, Kochhar A, Bhasin R. Effect of various malocclusion on maximal bite force- a systematic review. J Oral Biol Craniofac Res 2022; 12:687-693. [PMID: 36092457 PMCID: PMC9449769 DOI: 10.1016/j.jobcr.2022.08.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2022] [Revised: 05/13/2022] [Accepted: 08/10/2022] [Indexed: 11/18/2022] Open
Abstract
Objective This systematic review evaluates the variation in molar bite force (MBF) with the type and severity of dental malocclusion in young adults with permanent dentition. Methods We searched seven electronic databases until December 31, 2021, and identified 1898 articles, of which 22 full-texts were reviewed. Eight clinical studies with subjects having permanent dentition with various dental malocclusions and quantifying maximal bite force were included for the review. Newcastle Ottawa scale was used to assess the risk of bias and GRADE to study the certainty of evidence. Articles were evaluated for the primary outcome (variation of MBF in different malocclusion groups) and confounding factors affecting MBF. Results All studies measured MBF in individuals with normal and malocclusion, with 2329 subjects having permanent dentition. A positive correlation of Class I normal occlusion with the bite force was seen compared to Class II and III malocclusion. Unilateral crossbite patients had lesser bite force. Six studies with 1023 males and 1175 females showed MBF more in males than females. In 3 studies (332 subjects), no significant difference for MBF between the right and left sides of the jaws was measured. Conclusion MBF decreases significantly with vertical and transverse craniofacial and dental discrepancy. Normal sagittal occlusion has more molar bite force than patients with different malocclusions. Also, MBF is more in males than females, and it increases with age. Registration PROSPERO CRD42021249328.
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Affiliation(s)
- Harneet Kaur
- Orthodontics and Dentofacial Orthopaedics, Jamia Millia Islamia, New Delhi, India
| | - Neelam Singh
- Department of Conservative Dentistry and Endodontics, Jamia Millia Islamia, New Delhi, India
| | - Harshita Gupta
- Postgraduate Student, Sudha Rastogi College of Dental Sciences and Research, Faridabad, Haryana, India
| | | | - Pushpjot Sadana
- Former Post Graduate Student of Shri Guru Ram Das Institute of Dental Sciences and Research, Amritsar, India
| | - Natasha Gupta
- Department of Conservative Dentistry and Endodontics, Jamia Millia Islamia, New Delhi, India
| | - Anuraj Kochhar
- Department of Orthodontics, Faculty of Dentistry, University of Toronto, Toronto, Ontario, Canada
| | - Ritasha Bhasin
- Faculty of Dentistry, University of Toronto, Toronto, Ontario, Canada
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Lew AJ, Beniash E, Gilbert PUPA, Buehler MJ. Role of the Mineral in the Self-Healing of Cracks in Human Enamel. ACS NANO 2022; 16:10273-10280. [PMID: 35748426 DOI: 10.1021/acsnano.1c10407] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Human enamel is an incredibly resilient biological material, withstanding repeated daily stresses for decades. The mechanisms behind this resilience remain an open question, with recent studies demonstrating a crack-deflection mechanism contributing to enamel toughness and other studies detailing the roles of the organic matrix and remineralization. Here, we focus on the mineral and hypothesize that self-healing of cracks in enamel nanocrystals may be an additional mechanism acting to prevent catastrophic failure. To test this hypothesis, we used a molecular dynamics (MD) approach to compare the fracture behavior of hydroxyapatite (HAP) and calcite, the main minerals in human enamel and sea urchin teeth, respectively. We find that cracks heal under pressures typical of mastication by fusion of crystals in HAP but not in calcite, which is consistent with the resilience of HAP enamel that calcite teeth lack. Scanning transmission electron microscopy (STEM) images of structurally intact ("sound") human enamel show dashed-line nanocracks that resemble and therefore might be the cracks healed by fusion of crystals produced in silico. The fast, self-healing mechanism shown here is common in soft materials and ceramics but has not been observed in single crystalline materials at room temperature. The crack self-healing in sound enamel nanocrystals, therefore, is unique in the human body and unique in materials science, with potential applications in designing bioinspired materials.
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Affiliation(s)
- Andrew J Lew
- Laboratory for Atomistic and Molecular Mechanics (LAMM), Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States
- Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States
| | - Elia Beniash
- Departments of Oral Biology and Bioengineering, Center for Craniofacial Regeneration, McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, United States
| | - Pupa U P A Gilbert
- Department of Physics, University of Wisconsin, Madison, Wisconsin 53706, United States
- Departments of Chemistry, Materials Science and Engineering, Geoscience, University of Wisconsin, Madison, Wisconsin 53706, United States
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Markus J Buehler
- Laboratory for Atomistic and Molecular Mechanics (LAMM), Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States
- Center for Computational Science and Engineering, Schwarzman College of Computing, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States
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Fracture Resistance of Monolithic Zirconia Crowns Depending on Different Marginal Thicknesses. MATERIALS 2022; 15:ma15144861. [PMID: 35888327 PMCID: PMC9323601 DOI: 10.3390/ma15144861] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/04/2022] [Revised: 07/11/2022] [Accepted: 07/11/2022] [Indexed: 02/04/2023]
Abstract
Under some clinical conditions, the preparation of crowns of limited marginal thickness is inevitable. In such situations, it is questionable whether the same ideal preparation criteria can be applied equally. Since there are only a small number of studies focusing on the fracture resistance with respect to the marginal thickness, there is a need for a study evaluating whether zirconia crowns of limited marginal thickness are clinically acceptable. The purpose of this study is to evaluate the fracture resistance of monolithic zirconia crowns of limited marginal thickness in the posterior area. Methods: Abutments and CAD/CAM zirconia crowns with a marginal thickness of 1.0 mm were set as the control group, while experimental groups A, B, and C possessed reduced marginal thicknesses of 0.8 mm, 0.6 mm, and 0.4 mm, respectively (n = 10 per group). Resin-based abutment dies and monolithic zirconia crowns were fabricated using the CAD/CAM technique, and a universal testing machine was used to measure the fracture load value. Fractured specimens were examined with a scanning electron microscope. The data were analyzed using a one-way ANOVA and Bonferroni post hoc test (p < 0.05). Results: The means and standard deviations of the fracture load values of the control group and the three experimental groups were as follows: control group (1.0 mm): 3090.91 ± 527.77 N; group A (0.8 mm): 2645.39 ± 329.21 N; group B (0.6 mm): 2256.85 ± 454.15 N; group C (0.4 mm): 1957.8 ± 522.14 N. Conclusions: The crowns fabricated with a CAD/CAM zirconia block with limited marginal thicknesses of 0.6 mm and 0.4 mm showed significantly lower fracture resistance values compared to those with the recommended margin thickness of 1.0 mm.
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Jurado CA, Pinedo F, Trevino DAC, Williams Q, Marquez-Conde A, Irie M, Tsujimoto A. CAD/CAM lithium disilicate ceramic crowns: Effect of occlusal thickness on fracture resistance and fractographic analysis. Dent Mater J 2022; 41:705-709. [PMID: 35793941 DOI: 10.4012/dmj.2022-018] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
This study uses fracture tests and fractographical analysis to compare computer-aided design and computer-aided manufacturing (CAD/CAM) lithium disilicate molar crowns with the previous occlusal thickness recommendation of 1.5-mm, the new recommendation of 1.0-mm, and a less invasive thickness of 0.8-mm. After fatigue application, fracture tests and fractographic analysis were conducted. The fracture resistance of CAD/CAM lithium disilicate molar crowns was different depending on the occlusal thickness of the restoration, and decreased with lower the thickness. However, the fracture resistance of crowns of all three thicknesses exceeded the reported maximum bite force in the first molar region after the fatigue process, and can be considered acceptable for use in the clinic.
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Affiliation(s)
- Carlos A Jurado
- Texas Tech University Health Sciences Center El Paso, Woody L. Hunt School of Dental Medicine
| | | | | | | | - Alberto Marquez-Conde
- Department of Restorative Dentistry, Autonomous University of San Luis Potosi, Doctor
| | - Masao Irie
- Department of Biomaterials, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University
| | - Akimasa Tsujimoto
- Department of Operative Dentistry, University of Iowa College of Dentistry.,Department of General Dentistry, Creighton University School of Dentistry
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Donmez MB, Okutan Y. Marginal gap and fracture resistance of implant-supported 3D-printed definitive composite crowns: An in vitro study. J Dent 2022; 124:104216. [PMID: 35803388 DOI: 10.1016/j.jdent.2022.104216] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2022] [Revised: 06/20/2022] [Accepted: 07/04/2022] [Indexed: 12/21/2022] Open
Abstract
OBJECTIVES To compare the marginal gap and fracture resistance of implant-supported 3-dimensional (3D) printed definitive composite crowns with those fabricated by using 3 different millable materials. MATERIAL AND METHODS A prefabricated abutment was digitized by using a laboratory scanner (E4 Lab Scanner) and a complete-coverage maxillary first premolar crown was designed (Dental Designer). Forty crowns were fabricated either by 3D printing (Saremco Print Crowntec, SP) or milling (Brilliant Crios, BC; Vita Enamic, VE; Cerasmart 270, CS) (n = 10). Baseline marginal gap values were evaluated by measuring 60 predetermined points on an abutment (15 points for each side) with a stereomicroscope at ×40 magnification. Marginal gap values were reevaluated after adhesive cementation. Load-to-fracture test was performed by using a universal testing machine. Two-way analysis of variance (ANOVA) was used to evaluate the effect of material type and cementation on marginal gap values. While Tukey HSD tests were used to compare the materials' marginal gap values before and after cementation, the effect of cementation on marginal gap values within each material was analyzed by using paired samples t-tests. Fracture resistance data were analyzed by using 1-way ANOVA (α=0.05). RESULTS Material type and cementation significantly affected marginal gap values (P < .001). Regardless of cementation, SP had the lowest marginal gap values (P < .001), while the differences among milled crowns were nonsignificant (P ≥ .14). Cementation significantly increased the marginal gap values (P < .001). Material type did not affect fracture resistance values (F = 1.589, P = .209). CONCLUSION Implant-supported 3D-printed composite crowns showed higher marginal adaptation compared with the milled crowns before and after cementation. In addition, all crowns endured similar forces before fracture.
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Affiliation(s)
- Mustafa Borga Donmez
- Department of Prosthodontics, Faculty of Dentistry, Istinye University, Istanbul, Turkey; Department of Reconstructive Dentistry and Gerodontology, School of Dental Medicine, University of Bern, Bern, Switzerland.
| | - Yener Okutan
- Department of Prosthodontics, Aydin Adnan Menderes University Faculty of Dentistry, Aydin, Turkey.
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Chen Y, Lee JKY, Kwong G, Pow EHN, Tsoi JKH. Morphology and fracture behavior of lithium disilicate dental crowns designed by human and knowledge-based AI. J Mech Behav Biomed Mater 2022; 131:105256. [DOI: 10.1016/j.jmbbm.2022.105256] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2022] [Revised: 04/20/2022] [Accepted: 04/25/2022] [Indexed: 11/25/2022]
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Daniell H, Nair SK, Guan H, Guo Y, Kulchar RJ, Torres MD, Shahed-Al-Mahmud M, Wakade G, Liu YM, Marques A, Graham-Wooten J, Zhou W, Wang P, Molugu SK, de Araujo WR, de la Fuente-Nunez C, Ma C, Short WR, Tebas P, Margulies KB, Bushman FD, Mante FK, Ricciardi R, Collman RG, Wolff MS. Debulking different Corona (SARS-COV-2 delta, omicron, OC43) and influenza (H1N1, H3N2) virus strains by plant viral trap proteins in chewing gums to decrease infection and transmission. Biomaterials 2022; 288:121671. [PMID: 35953331 PMCID: PMC9290430 DOI: 10.1016/j.biomaterials.2022.121671] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2022] [Revised: 07/04/2022] [Accepted: 07/06/2022] [Indexed: 12/13/2022]
Abstract
Because oral transmission of SARS-CoV-2 is 3–5 orders of magnitude higher than nasal transmission, we investigated debulking of oral viruses using viral trap proteins (CTB-ACE2, FRIL) expressed in plant cells, delivered through the chewing gum. In omicron nasopharyngeal (NP) samples, the microbubble count (based on N-antigen) was significantly reduced by 20 μg of FRIL (p < 0.0001) and 0.925 μg of CTB-ACE2 (p = 0.0001). Among 20 delta or omicron NP samples, 17 had virus load reduced below the detection level of spike protein in the RAPID assay, after incubation with the CTB-ACE2 gum powder. A dose-dependent 50% plaque reduction with 50–100 ng FRIL or 600–800 μg FRIL gum against Influenza strains H1N1, H3N2, and Coronavirus HCoV-OC43 was observed with both purified FRIL, lablab bean powder or gum. In electron micrographs, large/densely packed clumps of overlapping influenza particles and FRIL protein were observed. Chewing simulator studies revealed that CTB-ACE2 release was time/dose-dependent and release was linear up to 20 min chewing. Phase I/II placebo-controlled, double-blinded clinical trial (IND 154897) is in progress to evaluate viral load in saliva before or after chewing CTB-ACE2/placebo gum. Collectively, this study advances the concept of chewing gum to deliver proteins to debulk oral viruses and decrease infection/transmission.
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Verkouteren DRC, de Sonnaville WFC, Zuithoff NPA, Wulffraat NM, Steenks MH, Rosenberg AJWP. Growth curves for mandibular range of motion and maximum voluntary bite force in healthy children. Eur J Oral Sci 2022; 130:e12869. [PMID: 35482417 PMCID: PMC9321901 DOI: 10.1111/eos.12869] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2022] [Accepted: 04/02/2022] [Indexed: 11/30/2022]
Abstract
Mandibular range of motion and bite force are indispensable variables for the evaluation of mandibular function. There are a variety of medical and dental conditions that can negatively affect mandibular function. Values for mandibular range of motion (i.e., active and passive maximum interincisal mouth opening, protrusion, and laterotrusion) and anterior maximum voluntary bite force (AMVBF) in healthy children and adolescents can help in recognizing temporomandibular dysfunction. In this longitudinal study, 169 healthy children aged 6-18 years were included. They were examined at four time points over 1 year. Mixed model analysis was performed to produce growth curves of mandibular range of motion and AMVBF. Average active maximum interincisal mouth opening was significantly higher in boys with 50.0 mm compared to 47.8 mm in girls. Boys also had a significantly higher AMVBF than girls with an average of 169.0 N versus 140.0 N, respectively. Growth curves of active and passive maximum interincisal mouth opening showed an increase with age, albeit levelling off through puberty. The growth curves of AMVBF in girls reach a plateau phase at ages 12-14 years, after which the curve descends; in boys, the AMVBF tended to increase up to 18 years of age, although a slow-down after 14 years of age was noted.
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Affiliation(s)
- Daan R C Verkouteren
- Department of Oral and Maxillofacial Surgery and Special Dental Care, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands
| | - Willemijn F C de Sonnaville
- Department of Oral and Maxillofacial Surgery and Special Dental Care, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands
| | - Nicolaas P A Zuithoff
- Julius Center for Health Sciences and Primary Care, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands
| | - Nico M Wulffraat
- Department of Pediatric Rheumatology and Immunology, Wilhelmina Children's Hospital, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands
| | - Michel H Steenks
- Department of Oral and Maxillofacial Surgery and Special Dental Care, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands
| | - Antoine J W P Rosenberg
- Department of Oral and Maxillofacial Surgery and Special Dental Care, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands
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Daniell H, Nair SK, Esmaeili N, Wakade G, Shahid N, Ganesan PK, Islam MR, Shepley-McTaggart A, Feng S, Gary EN, Ali AR, Nuth M, Cruz SN, Graham-Wooten J, Streatfield SJ, Montoya-Lopez R, Kaznica P, Mawson M, Green BJ, Ricciardi R, Milone M, Harty RN, Wang P, Weiner DB, Margulies KB, Collman RG. Debulking SARS-CoV-2 in saliva using angiotensin converting enzyme 2 in chewing gum to decrease oral virus transmission and infection. Mol Ther 2022; 30:1966-1978. [PMID: 34774754 PMCID: PMC8580552 DOI: 10.1016/j.ymthe.2021.11.008] [Citation(s) in RCA: 33] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2021] [Revised: 11/03/2021] [Accepted: 11/07/2021] [Indexed: 12/29/2022] Open
Abstract
To advance a novel concept of debulking virus in the oral cavity, the primary site of viral replication, virus-trapping proteins CTB-ACE2 were expressed in chloroplasts and clinical-grade plant material was developed to meet FDA requirements. Chewing gum (2 g) containing plant cells expressed CTB-ACE2 up to 17.2 mg ACE2/g dry weight (11.7% leaf protein), have physical characteristics and taste/flavor like conventional gums, and no protein was lost during gum compression. CTB-ACE2 gum efficiently (>95%) inhibited entry of lentivirus spike or VSV-spike pseudovirus into Vero/CHO cells when quantified by luciferase or red fluorescence. Incubation of CTB-ACE2 microparticles reduced SARS-CoV-2 virus count in COVID-19 swab/saliva samples by >95% when evaluated by microbubbles (femtomolar concentration) or qPCR, demonstrating both virus trapping and blocking of cellular entry. COVID-19 saliva samples showed low or undetectable ACE2 activity when compared with healthy individuals (2,582 versus 50,126 ΔRFU; 27 versus 225 enzyme units), confirming greater susceptibility of infected patients for viral entry. CTB-ACE2 activity was completely inhibited by pre-incubation with SARS-CoV-2 receptor-binding domain, offering an explanation for reduced saliva ACE2 activity among COVID-19 patients. Chewing gum with virus-trapping proteins offers a general affordable strategy to protect patients from most oral virus re-infections through debulking or minimizing transmission to others.
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Affiliation(s)
- Henry Daniell
- Department of Basic and Translational Sciences, School of Dental Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.
| | - Smruti K Nair
- Department of Basic and Translational Sciences, School of Dental Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Nardana Esmaeili
- Department of Basic and Translational Sciences, School of Dental Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Geetanjali Wakade
- Department of Basic and Translational Sciences, School of Dental Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Naila Shahid
- Department of Basic and Translational Sciences, School of Dental Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Prem Kumar Ganesan
- Department of Basic and Translational Sciences, School of Dental Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Md Reyazul Islam
- Department of Basic and Translational Sciences, School of Dental Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Ariel Shepley-McTaggart
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Sheng Feng
- Department of Medicine, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA
| | - Ebony N Gary
- The Wistar Institute, 3601 Spruce Street, Philadelphia, PA 19104, USA
| | - Ali R Ali
- The Wistar Institute, 3601 Spruce Street, Philadelphia, PA 19104, USA
| | - Manunya Nuth
- Department of Basic and Translational Sciences, School of Dental Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Selene Nunez Cruz
- Department of Medicine, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA
| | - Jevon Graham-Wooten
- Department of Medicine, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA
| | | | | | - Paul Kaznica
- Fraunhofer USA, Center Mid-Atlantic, Newark, DE 19711, USA
| | | | - Brian J Green
- Fraunhofer USA, Center Mid-Atlantic, Newark, DE 19711, USA
| | - Robert Ricciardi
- Department of Basic and Translational Sciences, School of Dental Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Michael Milone
- Department of Medicine, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA
| | - Ronald N Harty
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Ping Wang
- Department of Medicine, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA
| | - David B Weiner
- The Wistar Institute, 3601 Spruce Street, Philadelphia, PA 19104, USA
| | - Kenneth B Margulies
- Department of Medicine, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA
| | - Ronald G Collman
- Department of Medicine, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA
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Turksayar AAD, Donmez MB, Olcay EO, Demirel M, Demir E. Effect of printing orientation on the fracture strength of additively manufactured 3-unit interim fixed dental prostheses after aging. J Dent 2022; 124:104155. [DOI: 10.1016/j.jdent.2022.104155] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2022] [Revised: 04/28/2022] [Accepted: 05/04/2022] [Indexed: 11/17/2022] Open
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Micovic Soldatovic D, Liebermann A, Huth KC, Stawarczyk B. Fracture load of different veneered and implant-supported 4-UNIT cantilever PEEK fixed dental prostheses. J Mech Behav Biomed Mater 2022; 129:105173. [DOI: 10.1016/j.jmbbm.2022.105173] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2022] [Revised: 03/04/2022] [Accepted: 03/07/2022] [Indexed: 11/16/2022]
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ZHOU SHANYU, YOU YUEHUA, HU CHEN, SUN TING, SHAO LONGQUAN. FRACTOGRAPHIC ANALYSIS OF LITHIUM DISILICATE CERAMICS AND MONOLITHIC ZIRCONIA CERAMICS. J MECH MED BIOL 2022. [DOI: 10.1142/s0219519422400127] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Objective: To compare the fracture mode of lithium disilicate ceramics and zirconia ceramics through a single-load-to-failure test, and reveal the cause of failure through the fractographic analysis of fracture morphology. Methods: Based on the standardized preparations, 10 IPS e.max disilicate ceramic crowns (IPCs) and 10 monolithic zirconia ceramic crowns (MZCs) were designed and fabricated. All the specimens were placed on a universal material testing machine for a single-load-to-failure test. The fracture load was recorded, and two independent sample [Formula: see text]-tests were performed. Additionally, the type of fracture under a stereo-microscope was observed, and the morphological characteristics of the fracture with a scanning electron microscope (SEM) were investigated. Results: The fracture load of the IPC group was [Formula: see text][Formula: see text]N, and that of the MZC group was [Formula: see text][Formula: see text]N, with a statistically significant difference ([Formula: see text], [Formula: see text]). The fracture types of the IPC group and the MZC group were similar, namely, types II and III. The fracture modes of the two groups were all ceramic layer fracture. Through SEM, the origin of the crack on the occlusal surface could be traced back. The crystal fracture of IPC group had a rock sugar-like pattern, and the crystal distribution of MZC group was uniform. Conclusions: Zirconia ceramics have higher fracture load and a denser crystal structure compared to lithium disilicate. Fractographic analysis method could be a better way to analyze the failure mode of single-layer porcelain materials and reveal the origin of fracture.
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Affiliation(s)
- SHANYU ZHOU
- Department of Stomatology, Affiliated Longhua People’s Hospital, Southern Medical University, Shenzhen, Guangdong 518109, P. R. China
| | - YUEHUA YOU
- Department of Stomatology, Affiliated Longhua People’s Hospital, Southern Medical University, Shenzhen, Guangdong 518109, P. R. China
| | - CHEN HU
- Department of Stomatology, Nanfang Hospital, Southern Medical University Guangzhou, Guangdong 510515, P. R. China
| | - TING SUN
- The Affiliated Stomatology Hospital, Foshan University, Foshan, Guangdong 528000, P. R. China
| | - LONGQUAN SHAO
- Department of Stomatology, Nanfang Hospital, Southern Medical University Guangzhou, Guangdong 510515, P. R. China
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Jockusch J, Hahnel S, Sobotta BBAJ, Nitschke I. The Effect of a Masticatory Muscle Training Program on Chewing Efficiency and Bite Force in People with Dementia. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2022; 19:ijerph19073778. [PMID: 35409460 PMCID: PMC8997984 DOI: 10.3390/ijerph19073778] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Revised: 03/08/2022] [Accepted: 03/11/2022] [Indexed: 12/04/2022]
Abstract
Until now, no study has investigated the effects of masticatory muscle training on chewing function in people with dementia. This study aimed to investigate whether physiotherapeutic exercises for the masticatory muscles have an influence on chewing efficiency and bite force in people with dementia. In a clinical trial with stratified randomization subjects were assigned to three groups based on the Mini Mental State Examination (MMSE: group 1—28–30, group 2—25–27, group 3—18–24). Each group was divided into an experimental (ExpG, intervention) and control group (ConG, no intervention). As intervention a Masticatory Muscle Training (MaMuT) (part 1: three physiotherapeutic treatments and daily home exercises, part 2: daily home exercises only) was carried out. Chewing efficiency and bite force were recorded. The MaMuT influenced the masticatory performance regardless of the cognitive state. Bite force increased in ExpG 1 and 2. Without further training, however, the effect disappeared. Chewing efficiency increased in all ExpG. After completion of the training, the ExpG 2 and 3 showed a decrease to initial values. Subjects of ExpG 1 showed a training effect at the final examination, but a tendency toward the initial values was observed. ExpG 3 seemed to benefit most from the physiotherapeutic exercises in terms of improving chewing efficiency by the end of the intervention phase. ExpG 1 showed the greatest gain in bite force. The MaMuT program is a potential method of improving masticatory performance in people with cognitive impairment or dementia when used on a daily basis.
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Affiliation(s)
- Julia Jockusch
- Department of Prosthodontics and Materials Science, Gerodontology Section, University of Leipzig, 04103 Leipzig, Germany; (S.H.); (B.B.A.J.S.); (I.N.)
- University Research Priority Program “Dynamics of Healthy Aging”, University of Zurich, Andreasstrasse 15/Box 2, 8050 Zurich, Switzerland
- Correspondence: or
| | - Sebastian Hahnel
- Department of Prosthodontics and Materials Science, Gerodontology Section, University of Leipzig, 04103 Leipzig, Germany; (S.H.); (B.B.A.J.S.); (I.N.)
| | - Bernhard B. A. J. Sobotta
- Department of Prosthodontics and Materials Science, Gerodontology Section, University of Leipzig, 04103 Leipzig, Germany; (S.H.); (B.B.A.J.S.); (I.N.)
| | - Ina Nitschke
- Department of Prosthodontics and Materials Science, Gerodontology Section, University of Leipzig, 04103 Leipzig, Germany; (S.H.); (B.B.A.J.S.); (I.N.)
- Clinic of General, Special Care and Geriatric Dentistry, Center of Dental Medicine, University of Zurich, 8032 Zurich, Switzerland
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The OrBiD (Oral Health, Bite Force and Dementia) Pilot Study: A Study Protocol for New Approaches to Masticatory Muscle Training and Efficient Recruitment for Longitudinal Studies in People with Dementia. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2022; 19:ijerph19063700. [PMID: 35329390 PMCID: PMC8992135 DOI: 10.3390/ijerph19063700] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/18/2022] [Revised: 03/08/2022] [Accepted: 03/10/2022] [Indexed: 01/27/2023]
Abstract
Research with people with dementia is a great challenge in terms of recruitment, study participation and adherence to interventions resulting in less research activity and higher financial, organizational and personnel efforts. As dementia progresses, there is a deterioration in general and oral health and chewing function. Oral treatment options often focus on healthy patients. Interventions for people with dementia are needed. The aims of the paper were to describe the study protocol of the OrBiD (Oral Health, Bite Force and Dementia) pilot study as well as the description of two new methodological approaches. These are (A) an efficient recruitment process of people with dementia, simultaneous double study participation and (B) a novel approach to train the masticatory muscles by using physiotherapy. A novel methodology for the recruitment process (A) and, in particular, for the assignment of subjects to the experimental and control groups was developed and successfully tested. Additionally, a physiotherapy program (B) to train strength and coordination of the masticatory muscles was newly developed with the challenge to ensure that this training could also be carried out with people with cognitive impairments and dementia, if necessary, in cooperation with their relatives or caregivers. This was also successfully implemented. Recommendations for a feasibility assessment of a study involving people with dementia were made considering the organizational effort, the required personnel, structural and financial resources, the required number of subjects and the type of study design. When planning crossed studies, it must be ensured that the content, the interventions or their possible results of the study arms do not influence each other. The overall aim of this paper is to demonstrate the sustainable and efficient feasibility of studies with people with dementia.
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Wintergerst A, Gómez-Zúñiga RS. The effect of bolus size on masticatory parameters at swallowing threshold in children using a hard, solid, artificial test food. J Texture Stud 2022; 53:374-382. [PMID: 35243636 PMCID: PMC9313547 DOI: 10.1111/jtxs.12671] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2021] [Revised: 02/23/2022] [Accepted: 02/25/2022] [Indexed: 11/28/2022]
Abstract
The effect of different bolus sizes on food breakdown has been studied in adults, but not in children. The objective of this study was to study median particle size (MPS) and other parameters of masticatory function at swallowing threshold (ST) in 8–10‐year‐old‐children with two different bolus sizes. A randomized crossover trial was undertaken in 89 eight to ten‐year‐old children. The study was performed with informed consent and ethical approval. The artificial test food used was made of a condensation silicone (Optosil Comfort) following a standardized protocol. Two bolus sizes (three or four quarters of a 20‐mm diameter, 5‐mm thick tablet) were randomized to avoid an order effect and tested in different sessions. Variables were: MPS (X50) at ST, number of cycles until ST, sequence and cycle duration as well as cycles/g. Comparisons were performed with paired t and Wilcoxon tests, regressions and correlations were run. Cutoff for statistical significance was .05. Statistically significant differences were found for all variables; X50 (2.5 ± 0.8 vs. 2.8 ± 0.7 mm, p < .001), cycles until ST (38 vs. 40, p = .022), sequence (25 vs. 27 s, p = .003), and cycle duration (650 vs. 683 ms, p = .015) and cycles/g (27 vs. 21 cycles/g, p < .001), three or four quarters, respectively. In conclusion, in children, as in adults, chewing on a bigger bolus size leads to a larger MPS (X50) at ST. When chewing on a larger bolus the number of cycles increases, but not enough to swallow the same particle size since the number of cycles/g is less with a bigger bolus size.
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Affiliation(s)
- Ana Wintergerst
- Graduate School of Dentistry, Universidad Nacional Autónoma de México, México City, México.,Facultad de Estudios Superiores Zaragoza, Universidad Nacional Autónoma de México, México City, México
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Prabahar T, Gupta N, Chowdhary N, Sonnahalli NK, Chowdhary R, Reddy VR. Comparative Evaluation of Occlusal Bite Force in Relation to the Muscle Activity in the Mixed Dentition Children of Age Group 9-12 Years: A T-scan Analysis. Int J Clin Pediatr Dent 2022; 14:S29-S34. [PMID: 35082463 PMCID: PMC8754266 DOI: 10.5005/jp-journals-10005-2019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Aim and objective Compare and evaluate the muscle activity and the occlusal force between the mixed dentition boys and girls of 9-12 years. Materials and methods The study included 15 boys and 15 girls. The occlusal force and activity of the masseter and temporalis muscle were measured with a T-scan device using a sensor, a module to transmit the signals to a computer and the complete data of the bite force and muscle activity with the EMG recordings and data were collected and evaluated. Results Relative occlusal force in the primary and permanent molars between the boys and girls showed no significant difference on the left side compared to the right. The electromyography values of masseter and temporalis in boys and girls showed a significant difference in which (TAR and MMR), (TAR and MML), (TAL and MMR), and (TAL and MML) are significant. The overall paired sample statistics showed higher muscle activity in masseter. Conclusion T-scan analysis has proved to be a dependable method for the evaluation of occlusal bite force with the muscle activity interpretation using EMG. This study concluded that there is a difference in the occlusal pattern and muscle activity in the mixed dentition that showed the maximum force was on the permanent molars and the symmetry of EMGs activity in children was on the right masseter comparatively with higher bite values in boys compared to girls. Clinical significance T-scan is a computerized analysis system that helps in the proper assessment of the patient's occlusion and assists in the proper treatment planning and diagnosis accurately without much effort. How to cite this article Prabahar T, Gupta N, Chowdhary NR, et al. Comparative Evaluation of Occlusal Bite Force in Relation to the Muscle Activity in the Mixed Dentition Children of Age Group 9-12 Years: A T-scan Analysis. Int J Clin Pediatr Dent 2021;14(S-1):S29-S34.
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Affiliation(s)
- Tanuja Prabahar
- Department of Pedodontics and Preventive Dentistry, Sri Siddhartha Dental college and Hospital, Sri Siddhartha Academy of Higher Education, Tumakuru, Karnataka, India
| | - Nisha Gupta
- Department of Pedodontics and Preventive Dentistry, Sri Siddhartha Dental college and Hospital, Sri Siddhartha Academy of Higher Education, Tumakuru, Karnataka, India
| | - Nagalakshmi Chowdhary
- Department of Pedodontics and Preventive Dentistry, Sri Siddhartha Dental college and Hospital, Sri Siddhartha Academy of Higher Education, Tumakuru, Karnataka, India
| | - Nithin Kumar Sonnahalli
- Department of Prosthodontics, Sri Siddhartha Dental college and Hospital, Sri Siddhartha Academy of Higher Education, Tumakuru, Karnataka, India
| | - Ramesh Chowdhary
- Brånemark Osseointegration Center India, Vijaynagar, Bengaluru, Karnataka, India
| | - Vundela Rajashekar Reddy
- Department of Pedodontics and Preventive Dentistry, Sri Siddhartha Dental college and Hospital, Sri Siddhartha Academy of Higher Education, Tumakuru, Karnataka, India
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Patel K N A, Girish G, Akarsh R, Nikhila G, Bhat P, Shabadi N. Comparative evaluation of bite force in patients treated for unilateral mandibular condylar fractures by open and closed methods. Dent Traumatol 2022; 38:223-228. [PMID: 35084092 DOI: 10.1111/edt.12733] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2021] [Revised: 01/01/2022] [Accepted: 01/04/2022] [Indexed: 11/03/2022]
Abstract
BACKGROUND/AIM Condylar fractures account for a large proportion (20% to 52%) of mandibular injuries. The goal of treating these fractures is to restore the occlusion, thereby re-establishing the masticatory function as close as possible to the patient's pre-trauma state. The aim of this study was to compare the bite forces following unilateral condylar fractures treated by open reduction and internal fixation (ORIF) with those managed by the closed method. METHOD Patients with unilateral mandibular condylar fractures were divided into two groups (n = 20) using a simple randomization method. Patients in group I were treated by open reduction and internal fixation (ORIF) using titanium miniplates and screws. Patients in group II were treated by the closed method with inter-maxillary fixation. Patients in both groups were evaluated pre-operatively and then post-operatively at one week, one month and three months for maximum bite force achieved at the central incisor, premolar and molar regions. RESULTS Pre-operative bite forces on the unaffected site were significantly higher than the affected site in both groups, whereas no significant difference was observed in bite forces between the unaffected and affected sites in both groups post-operatively. The bite forces achieved at both the unaffected and affected sites in the ORIF group were significantly higher than in the closed group. CONCLUSION Maximum bite forces differed significantly when the treatment was done with the open method, and the patients treated with the open method needed less time to achieve the maximum bite forces, thereby making an earlier return to function.
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Affiliation(s)
- A Patel K N
- Department of Facio-Maxillary Surgery, Sanjay Gandhi Institute of Trauma and Orthopaedics, Bangalore, India
| | - G Girish
- Department of Facio-Maxillary Surgery, Sanjay Gandhi Institute of Trauma and Orthopaedics, Bangalore, India
| | - R Akarsh
- Department of Facio-Maxillary Surgery, Sanjay Gandhi Institute of Trauma and Orthopaedics, Bangalore, India
| | - G Nikhila
- Department of Facio-Maxillary Surgery, Sanjay Gandhi Institute of Trauma and Orthopaedics, Bangalore, India
| | - Preethi Bhat
- Department of Facio-Maxillary Surgery, Sanjay Gandhi Institute of Trauma and Orthopaedics, Bangalore, India
| | - Nikita Shabadi
- Department of Facio-Maxillary Surgery, Sanjay Gandhi Institute of Trauma and Orthopaedics, Bangalore, India
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Bite Force, Occlusal Contact and Pain in Orthodontic Patients during Fixed-Appliance Treatment. Dent J (Basel) 2022; 10:dj10020014. [PMID: 35200240 PMCID: PMC8871092 DOI: 10.3390/dj10020014] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2021] [Revised: 01/12/2022] [Accepted: 01/17/2022] [Indexed: 01/14/2023] Open
Abstract
Previously, bite force, occlusal contact and pain were investigated in orthodontic patients with moderate-to-severe malocclusion, but not in patients with minor malocclusion. The purpose of this study was to investigate changes in bite force, teeth in occlusal contact and pain in orthodontic patients with minor crowding before orthodontic treatment (T0), after bonding (T1), during treatment (T2), post-treatment (T3) and during retention (T4). In total, 27 patients (21 females, 6 males, median age 15.3 years) with neutral occlusion and normal craniofacial morphology were treated with non-extractions and fixed appliances. Differences in the registered data were analysed by a mixed linear model with repeated measures. Bite force and teeth in occlusal contact significantly decreased between T0 and T1 (p < 0.0001, respectively) and between T0 and T2 (p < 0.01, respectively). Bite force and teeth in occlusal contact significantly increased between T1 and T4 (p < 0.05, p < 0.0001, p < 0.001, respectively) and between T2 and T4 (p < 0.05, p < 0.0001, p < 0.01, respectively). No significant difference in pain was found. The results indicate that bite force and teeth in occlusal contact significantly decreased during treatment and reached baseline level at retention. The findings may prove valuable for informing orthodontic patients with minor malocclusion.
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