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Demir N, Genc O, Akkese IB, Malkoc MA, Ozcan M. Bonding Effectiveness of Saliva-Contaminated Monolithic Zirconia Ceramics Using Different Decontamination Protocols. BIOMED RESEARCH INTERNATIONAL 2024; 2024:6670159. [PMID: 38606199 PMCID: PMC11008971 DOI: 10.1155/2024/6670159] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/21/2023] [Revised: 03/07/2024] [Accepted: 03/16/2024] [Indexed: 04/13/2024]
Abstract
Objective This research study investigated the effect of new decontamination protocols on the bonding capacity of saliva-contaminated monolithic zirconia (MZ) ceramics cemented with two different monomer-containing self-adhesive resin cements. Materials and Methods Standardized tooth preparations (4 mm. axial height) were performed for eighty human maxillary premolars under constant water cooling system. Eighty monolithic zirconia crowns (Whitepeaks Supreme Monolith) (n = 8/10 groups) were manufactured by CAD-CAM. Specimens were kept in the artificial saliva at pH = 7.3 for 1 minute at 37°C except control groups. The specimens have not been prealumina blasted and grouped according to cleaning methods and resin cements: control groups (C) (no saliva contamination + GPDM + 4-META (N) (CN) and 10-MDP (M) containing resin cement (CM), alumina blasted (AL) + GPDM + 4-META (ALN) and 10-MDP containing resin cement (ALM), zirconium oxide containing universal cleaning agent (IC) applied + GPDM + 4-META (N) (ICN) and 10-MDP containing resin cement (ICM), pumice (P) applied + GPDM + 4-META (PN) and 10-MDP containing resin cement (PM), and air-water spray (AW) applied + GPDM + 4-META (AWN) and 10-MDP containing resin cement (AWM)). Monobond Plus was applied to all surfaces for 40 seconds before cementation. The thermal cycle was applied at 5,000 cycles after cementation. The crowns were tested in tensile mode at a speed of 1 mm/min. The mode of failure was recorded. SEM examinations were carried out at different magnifications. Data were analyzed using rank-based Kruskal-Wallis and Mann-Whitney tests. Results No significant differences were found between the surface treatments and between the two types of resin cements. Interaction effects between surface treatments and resin cements were found to be significant by two-way ANOVA analysis. ICM group resulted in significantly better bond strength results compared with CN. ICM was found to result in better bond strength results compared with PM. The combination of universal cleaning agent and 10-MDP containing resin cement had significantly the highest cementation bond strength values. The increasing order of mean tensile bond strength values of decontamination protocols was C < AW < P < AL < IC. The mean tensile bond strength of 10-MDP containing resin cement was slightly higher than GPDM + 4-META containing resin cement. Conclusions Universal cleaning agents can be preferred as an efficient cleaning method with 10-MDP-containing cement after saliva contamination for better adhesive bond strength of 4 mm crown preparation height of monolithic zirconia ceramics.
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Affiliation(s)
- Necla Demir
- Selcuk University, Faculty of Dentistry, Department of Prosthodontics, Konya, Türkiye
| | - Ozge Genc
- Selcuk University, Faculty of Dentistry, Department of Prosthodontics, Konya, Türkiye
| | - Ipek Balevi Akkese
- Selcuk University, Faculty of Dentistry, Department of Prosthodontics, Konya, Türkiye
| | - Meral Arslan Malkoc
- Akdeniz University, Faculty of Dentistry, Department of Prosthodontics, Antalya, Türkiye
| | - Mutlu Ozcan
- Clinic for Fixed and Removable Prosthodontics and Dental Materials Science, Center for Dental and Oral Medicine, University of Zurich, Zurich, Switzerland
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Bataineh K, Al Janaideh M. Fatigue behavior of three thin CAD/CAM all-ceramic crown materials. Int Biomech 2023; 10:1-8. [PMID: 38205926 PMCID: PMC10786422 DOI: 10.1080/23335432.2024.2303121] [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: 03/23/2020] [Accepted: 01/03/2024] [Indexed: 01/12/2024] Open
Abstract
The purpose of this study was to study the effect of crown thickness on the fatigue life of CAD/CAM ceramic materials. CAD/CAM ceramic materials for the crown were virtually designed with three thickness designs of (a) ultra-thin occlusal crown average 0.7 mm thick (group A), (b) thin occlusal crown 1.1 mm average thick (group B), (c) thick occlusal crown 1.5 mm thick. The materials are: zirconia Cercon ZC and IPS e.max CAD (LD). Finite Element Analysis (FEA) simulations were carried out to estimate the fatigue lives of restorative materials. The lives for groups B and C under fatigue load were not significantly different from each other for Zirconia. The predicted lives for group A zirconia crowns, under fatigue load 50 N, 100 N, 120 N is 24 years, 4.3 years, 1.9 years, respectively. Results for crowns made of LD can be summarized as follows: under load 50 N, all groups have survived longer than 5 respectively, while under the load of 100 N, only group C survived longer than 5 years. 0.7 mm thick full contour Zirconia crowns possessed adequate endurance strength to survive under physiologic conditions. On the other hand, the crown made of LD should have at least 1.5 mm thickness to survive longer than 5 years.
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Affiliation(s)
- Khaled Bataineh
- Department of Mechanical Engineering, Jordan University of Science and Technology, Irbid, Jordan
| | - Mohammad Al Janaideh
- Department of Mechanical Engineering, Jordan University of Science and Technology, Irbid, Jordan
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Aziz AM, El-Mowafy O. Clinical evaluation of zirconia crowns cemented with two different resin cements: A retrospective study. J Oral Rehabil 2023; 50:1481-1486. [PMID: 37638559 DOI: 10.1111/joor.13580] [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: 03/22/2023] [Revised: 05/28/2023] [Accepted: 08/17/2023] [Indexed: 08/29/2023]
Abstract
BACKGROUND Self-adhesive resin cement has been used extensively with zirconia crowns. Several in vitro studies showed that adhesive resin cementation may increase zirconia crowns' retention and their fatigue resistance. OBJECTIVES This retrospective study aimed to evaluate the clinical performance, survival and success rates and complications encountered with zirconia crowns cemented with two different self-adhesive resin cements. METHODS A total of 112 patients who received 176 monolithic zirconia crowns were evaluated. Crowns were cemented with RelyX Unicem 2 (n = 74) and Panavia SA (n = 102) self-adhesive resin cements. Clinical assessments of the crowns and supporting periodontal structures were performed following the modified California Dental Association (CDA) criteria. Intraoral photographs and periapical and bitewing radiographs were obtained for further assessment by two evaluators. Descriptive statistics, McNemar, t-test, log rank (Mantel-Cox) tests and Kaplan-Meier survival analyses were performed (a = .05). RESULTS The 5-year survival and success rates were 100% and 96.4%, respectively. The complications encountered were recurrent caries (2.2%) and the need for endodontic treatment (0.5%). No technical complications, such as fracture or loss of retention, were observed. The type of cement and patient-related factors did not influence the survival and success rates of the crowns. CONCLUSIONS Survival rate of zirconia crowns cemented with two different self-adhesive resin cements was 100% after 5 years.
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Affiliation(s)
- Ahmed M Aziz
- Department of Restorative and Preventive Dentistry, College of Dental Medicine, University of Sharjah, Sharjah, UAE
| | - Omar El-Mowafy
- Department of Restorative Dentistry, Faculty of Dentistry, University of Toronto, Toronto, Ontario, Canada
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Liu X, Aarts JM, Ma S, Choi JJE. The impact of different polishing systems on yttria-stabilized tetragonal zirconia polycrystalline crowns in relation to heat generation. Clin Exp Dent Res 2023; 9:799-809. [PMID: 37608597 PMCID: PMC10582218 DOI: 10.1002/cre2.778] [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: 05/07/2023] [Revised: 08/03/2023] [Accepted: 08/10/2023] [Indexed: 08/24/2023] Open
Abstract
OBJECTIVES To investigate the heat generation on yttria-stabilized tetragonal zirconia polycrystalline (Y-TZP) crowns during polishing with coarse and fine polishing systems at various speeds. MATERIALS AND METHODS Two polishers (coarse and fine) at three polishing speeds were investigated. Two simulation models of the first mandibular molars were prepared for full coverage Y-TZP restorations with different reduction dimensions. Preheated water was pumped into the abutment chamber, to simulate the intrapulpal temperature and blood flow. Twelve Y-TZP crowns (3M™ Lava™ Esthetic) were milled for each prepared tooth abutment and each cusp (n = 10) was individually ground for 30 s and polished for 2 min. Thermocouple wire was secured to the intaglio surface of the crown and linked to a data logger for recording temperature changes. Selected scanning electron microscopy (SEM) images of the treated surfaces and polishers were analyzed. The data was statistically analyzed using Prism 9. RESULTS The highest temperature rise was observed in the 20,000 RPM polishing speed groups for both coarse and fine polishing, and higher than the threshold value of 5.5°C for pulp damage. The Kruskal-Wallis test, revealed statistically significant differences (p < .0001) in heat generation between low (10,000 RPM) and high (20,000 RPM) polishing speeds. CONCLUSIONS High-speed polishing at 20,000 RPM generated the most heat over the threshold of 5.5°C, which would threaten the dental pulp. The results suggest that a cautionary approach should be taken to high-speed intraoral polishing. CLINICAL RELEVANCE Dental clinicians should be aware of the choice of polishing systems and speeds to avoid pulp damage from intraoral polishing of Y-TZP restorations.
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Affiliation(s)
- Xiaoyun Liu
- Sir John Walsh Research Institute, Faculty of DentistryUniversity of OtagoDunedinNew Zealand
| | - John M. Aarts
- Sir John Walsh Research Institute, Faculty of DentistryUniversity of OtagoDunedinNew Zealand
| | - Sunyoung Ma
- Sir John Walsh Research Institute, Faculty of DentistryUniversity of OtagoDunedinNew Zealand
| | - Joanne Jung Eun Choi
- Sir John Walsh Research Institute, Faculty of DentistryUniversity of OtagoDunedinNew Zealand
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Refaie A, Fouda A, Bourauel C, Singer L. Marginal gap and internal fit of 3D printed versus milled monolithic zirconia crowns. BMC Oral Health 2023; 23:448. [PMID: 37403169 DOI: 10.1186/s12903-023-03184-8] [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: 05/23/2023] [Accepted: 06/28/2023] [Indexed: 07/06/2023] Open
Abstract
BACKGROUND This study aimed to evaluate and compare the marginal gap using two different methods and the internal fit of 3D printed and zirconia crowns. METHODS 3Y-TZP zirconia crowns (n = 20) were manufactured using subtractive milling (group M) and 3D printed (group P). The marginal gap was measured at 60 points using vertical marginal gap technique (VMGT). On the other hand, the silicone replica technique (SRT) was used to evaluate the internal fit and was divided into 4 groups: marginal gap, cervical gap, axial gap, and occlusal gap where the thickness of light impression was measured at 16 references. The numerical data was tested for normality using Shapiro-Wilk's test. They were found to be normally distributed and were analyzed using an independent t-test. RESULTS Using VMGT, group P had significantly higher mean marginal gap values of 80 ± 30 µm compared to group M = 60 ± 20 µm (p < 0.001). Also, with the SRT, the marginal gap of group P (100 ± 10 µm) had significantly higher values compared to group M (60 ± 10 µm). The internal fit showed significant difference between the tested groups except for Axial Gap. CONCLUSIONS Although milled crowns showed better results. The 3D printed zirconia crowns offer clinically acceptable results in terms of marginal adaptation and internal fit. Both VMGT and SRT are reliable methods for the assessment of the marginal gap.
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Affiliation(s)
- Ashraf Refaie
- Oral Medicine Technology, University Hospital Bonn, Bonn, Germany.
- Department of Fixed Prosthodontics, Faculty of Dentistry, Fayoum University, Faiyum, Egypt.
- Faculty of Oral and Dental Medicine, British University in Egypt, Cairo, Egypt.
| | - Ahmed Fouda
- Oral Medicine Technology, University Hospital Bonn, Bonn, Germany
| | | | - Lamia Singer
- Oral Medicine Technology, University Hospital Bonn, Bonn, Germany
- Department of Orthodontics, University Hospital Bonn, Bonn, Germany
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Abd Alraheam I, Al-Asmar A, Hasan N, Asoleihat F, Alkayed A. Clinical evaluation of cemented and adhesively resin-bonded monolithic and partially layered zirconia and lithium disilicate crowns. Saudi Dent J 2023; 35:508-514. [PMID: 37520593 PMCID: PMC10373076 DOI: 10.1016/j.sdentj.2023.04.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2022] [Revised: 04/03/2023] [Accepted: 04/10/2023] [Indexed: 08/01/2023] Open
Abstract
Purpose Zirconia and lithium disilicate crowns are very popular dental restorations. The cement type and layering technique used can profoundly affect the clinical performance of these crowns.This retrospective study is designed to investigate the success rate of cemented and adhesively bonded monolithic and partially layered zirconia and lithium disilicate crowns placed in faculty practice settings. Materials and Methods Patients who had received zirconia or lithium disilicate crowns at the faculty practice were invited for clinical examination. The examiner used the modified United States Public Health Service (MUSPHS) evaluation criteria to evaluate the crowns. The crowns were either glass ionomer cemented zirconia (GIC-Zr), resin-bonded zirconia (Adh-Zr), or resin-bonded lithium disilicate (Adh-LD). The crowns were also divided into monolithic and layered groups. Inferential analysis was used to examine the differences through bivariate analysis using t-testing and one-way ANOVA. Results Thirty-five patients, with a combined total of 218 single crowns, agreed to participate in the study. No statistically significant differences in the quality outcome variables considered were found between the groups, except for marginal adaptation, where Adh-Zr achieved significantly higher scores compared to GIC-Zr and Adh-LD. Layered zirconia and lithium disilicate crowns have significantly higher quality outcomes in terms of anatomic form, marginal adaptation, and color match compared to monolithic zirconia and lithium disilicate crowns. Conclusions Conventionally cemented zirconia and adhesively bonded zirconia and lithium disilicate crowns are reliable treatment options with high short-term success rates. Clinical studies with longer follow-up times are needed to investigate their long-term success rates.
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Affiliation(s)
- Islam Abd Alraheam
- Department of Restorative Dentistry, University of Jordan, Amman, Jordan
| | - Aya Al-Asmar
- Department of Restorative Dentistry, University of Jordan, Amman, Jordan
| | - Noor Hasan
- Department of Restorative Dentistry, University of Jordan, Amman, Jordan
| | - Firas Asoleihat
- Department of Restorative Dentistry, University of Jordan, Amman, Jordan
| | - Awni Alkayed
- Department of Restorative Dentistry, University of Jordan, Amman, Jordan
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Calheiros-Lobo MJ, Vieira T, Carbas R, da Silva LFM, Pinho T. Effectiveness of Self-Adhesive Resin Luting Cement in CAD-CAM Blocks-A Systematic Review and Meta-Analysis. MATERIALS (BASEL, SWITZERLAND) 2023; 16:2996. [PMID: 37109832 PMCID: PMC10140979 DOI: 10.3390/ma16082996] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/27/2023] [Revised: 04/07/2023] [Accepted: 04/08/2023] [Indexed: 06/19/2023]
Abstract
Self-adhesive resin cements (SARCs) are used because of their mechanical properties, ease of cementation protocols, and lack of requirements for acid conditioning or adhesive systems. SARCs are generally dual-cured, photoactivated, and self-cured, with a slight increase in acidic pH, allowing self-adhesiveness and increasing resistance to hydrolysis. This systematic review assessed the adhesive strength of SARC systems luted to different substrates and computer-aided design and manufacturing (CAD/CAM) ceramic blocks. The PubMed/MedLine and Science Direct databases were searched using the Boolean formula [((dental or tooth) AND (self-adhesive) AND (luting or cement) AND CAD-CAM) NOT (endodontics or implants)]. Of the 199 articles obtained, 31 were selected for the quality assessment. Lava Ultimate (resin matrix filled with nanoceramic) and Vita Enamic (polymer-infiltrated ceramic) blocks were the most tested. Rely X Unicem 2 was the most tested resin cement, followed by Rely X Unicem > Ultimate > U200, and μTBS was the test most used. The meta-analysis confirmed the substrate-dependent adhesive strength of SARCs, with significant differences between them and between SARCs and conventional resin-based adhesive cement (α < 0.05). SARCs are promising. However, one must be aware of the differences in the adhesive strengths. An appropriate combination of materials must be considered to improve the durability and stability of restorations.
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Affiliation(s)
- Maria João Calheiros-Lobo
- UNIPRO—Oral Pathology and Rehabilitation Research Unit, University Institute of Health Sciences (IUCS), Cooperativa de Ensino Superior Politécnico e Universitário (CESPU), Rua Central de Gandra 1317, 4585-116 Gandra, Portugal
- Conservative Dentistry, Department of Dental Sciences, University Institute of Health Sciences (IUCS), Cooperativa de Ensino Superior Politécnico e Universitário (CESPU), Rua Central de Gandra 1317, 4585-116 Gandra, Portugal
| | - Tatiana Vieira
- UNIPRO—Oral Pathology and Rehabilitation Research Unit, University Institute of Health Sciences (IUCS), Cooperativa de Ensino Superior Politécnico e Universitário (CESPU), Rua Central de Gandra 1317, 4585-116 Gandra, Portugal
| | - Ricardo Carbas
- Department of Mechanical Engineering, Faculty of Engineering, University of Porto, 4200-465 Porto, Portugal
- INEGI—Institute of Science and Innovation in Mechanical and Industrial Engineering, University of Porto, 4200-465 Porto, Portugal
| | - Lucas F. M. da Silva
- Department of Mechanical Engineering, Faculty of Engineering, University of Porto, 4200-465 Porto, Portugal
- INEGI—Institute of Science and Innovation in Mechanical and Industrial Engineering, University of Porto, 4200-465 Porto, Portugal
| | - Teresa Pinho
- UNIPRO—Oral Pathology and Rehabilitation Research Unit, University Institute of Health Sciences (IUCS), Cooperativa de Ensino Superior Politécnico e Universitário (CESPU), Rua Central de Gandra 1317, 4585-116 Gandra, Portugal
- IBMC—Instituto Biologia Molecular e Celular, i3S—Instituto de Inovação e Investigação em Saúde, Institute for Molecular and Cell Biology (IBMC), Institute of Innovation and Investigation in Health (i3S), University of Porto, 4200-135 Porto, Portugal
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Çiftçi ZZ, Şahin İ, Karayılmaz H. Comparative evaluation of the fracture resistance of newly developed prefabricated fibreglass crowns and zirconium crowns. Int J Paediatr Dent 2022; 32:756-763. [PMID: 35102638 DOI: 10.1111/ipd.12954] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/26/2021] [Revised: 12/07/2021] [Accepted: 01/10/2022] [Indexed: 11/28/2022]
Abstract
BACKGROUND Prefabricated fibreglass crowns (PFCs) require less tooth structure reduction than prefabricated zirconium crowns (PZCs) for restoring primary molars. Little is known, however, about their mechanical properties. AIM To investigate the fatigue survival and fracture resistance of PZCs and PFCs cemented with two different types of luting cement [glass-ionomer cement (GIC) and resin-modified GIC (RMGIC)]. DESIGN One hundred and twenty extracted human primary molars were randomly divided into subgroups (n = 15) according to the crown type (PFCs/PZCs), the luting cement (GIC/RMGIC) and crowns subjected to the chewing simulation test with thermocycling mechanical loading (CSTTML). The surfaces of the teeth were reduced by approximately 2 mm in the PZC group and 1 mm in the PFC group. All the samples were subjected to fracture tests. RESULTS None of the samples subjected to CSTTML exhibited signs of surface damage, fracture or premature debonding. The forces required to fracture PFCs were higher than those required for PZCs in all groups (p = .001). The highest mean fracture resistance values were obtained from the group of PFCs cemented with GIC that were subjected to the CSTTML (2515.8 N ± 619.2 N). CONCLUSIONS PFCs presented high fatigue survival and could be used as alternatives to PZCs as they require less tooth structure reduction. Crowns cemented with GIC had a similar fracture resistance value when compared with RMGIC.
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Affiliation(s)
- Zülfikar Zahit Çiftçi
- Department of Paediatric Dentistry, Faculty of Dentistry, Akdeniz University, Antalya, Turkey
| | | | - Hüseyin Karayılmaz
- Department of Paediatric Dentistry, Faculty of Dentistry, Akdeniz University, Antalya, Turkey
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Skjold A, Schriwer C, Gjerdet NR, Øilo M. Fractographic analysis of 35 clinically fractured bi-layered and monolithic zirconia crowns. J Dent 2022; 125:104271. [PMID: 36041673 DOI: 10.1016/j.jdent.2022.104271] [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] [Received: 05/26/2022] [Revised: 07/12/2022] [Accepted: 08/25/2022] [Indexed: 10/15/2022] Open
Abstract
OBJECTIVES The aim of this retrieval study was to analyze the fracture features and identify the fracture origin of zirconia-based single crowns that failed during clinical use. METHODS Thirty-five fractured single crowns were retrieved from dental practices (bi-layered, n=15; monolithic, n=20). These were analyzed according to fractographic procedures by optical and scanning electron microscopy to identify fracture patterns and fracture origins. The fracture origins were closely examined. The crown margin thickness and axial wall height were measured. RESULTS Three types of failure modes were observed: total fractures, marginal semilunar fractures, and incisal chippings. Most of the crowns (23) had fracture origins at the crown margin and seven of them had defects in the fracture origin area. The exact fracture origin was not possible to identify due to missing parts in four crowns. The crown wall thickness was 20% thinner and wall height 30% shorter in the fracture origin area compared to the opposite side. CONCLUSIONS The findings in this study show that fractography can reveal fracture origins and fracture modes of both monolithic and bi-layered dental zirconia. The findings indicate that the crown margin on the shortest axial wall is the most common fracture origin site. CLINICAL SIGNIFICANCE Crown design factors such as material thickness at the margin, axial wall height and preparation type affects the risk of fracture. It is important to ensure that the crown margins are even and flawless.
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Affiliation(s)
- Anneli Skjold
- Department of Clinical Dentistry, Faculty of Medicine, University of Bergen, Aarstadveien 19. N-5009 Bergen, Norway.
| | - Christian Schriwer
- Department of Clinical Dentistry, Faculty of Medicine, University of Bergen, Aarstadveien 19. N-5009 Bergen, Norway.
| | - Nils Roar Gjerdet
- Department of Clinical Dentistry, Faculty of Medicine, University of Bergen, Aarstadveien 19. N-5009 Bergen, Norway.
| | - Marit Øilo
- Department of Clinical Dentistry, Faculty of Medicine, University of Bergen, Aarstadveien 19. N-5009 Bergen, Norway.
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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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AlAali KA, AlHelal A, Almahri JR, Albakri AA, Albani RM, Alhaizan YA, Alhamdan MM, Alaql NA, Binhasan M, Alhamdan EM, Albaqawi AH, Vohra F, Abduljabbar T. Influence of Conventional Polymer, Hybrid Polymer and Zinc Phosphate Luting Agents on the Bond Strength of Customized Zirconia Post in Premolars-An In-Vitro Evaluation. Polymers (Basel) 2022; 14:polym14040758. [PMID: 35215671 PMCID: PMC8879678 DOI: 10.3390/polym14040758] [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: 01/16/2022] [Revised: 02/02/2022] [Accepted: 02/04/2022] [Indexed: 02/01/2023] Open
Abstract
The aim was to identify the influence of conventional polymeric resin based cement (RC), hybrid polymer modified glass ionomer (RMGIC) and Zinc phosphate cement (ZPC) on the pull out strength of the customized zirconia post in premolars. Access cavity and root canals were performed in sixty premolar teeth with the standardized crown down technique (ProTaper Universal, Dentsply). Post space impressions were scanned, and the pre-sintered Zenostar Zr Translucent blanks (Weiland Dental, Pforzheim) were milled with the Opera-system to form the post. All prepared specimens were divided equally in three groups based on the cement type employed for luting as follows: group A: ZPC; group B (GC Fuji PLUS Capsule): RMGIC; group C (and RC (3M RelyX ARC). Ten specimens in each group were thermocycled (TC) at 5 and 55 °C in distilled water baths (40,000 cycles). Pull out bond strength was assessed using a universal testing machine at 0.5 mm/min. The means and standard deviations were compared using ANOVA and Tukey Kramer multiple comparisons tests. A significant difference among the cement groups as well as between TC and non-thermocycled (NTC) groups (p < 0.05) was observed. The highest tensile stress was demonstrated among group C (Resin, 69.89 ± 4.81 (NTC), 64.06 ± 4.36 (TC)) with the least in group A, (zinc phosphate, 43.66 ± 5.02 (NTC), 37.70 ± 5.10 (TC)) for both groups. Group A presented with 100% adhesive bond failures, followed by 80% in group C and 70% in group B, respectively. A similar outcome was observed in the TC group for the cement; however, unlike the NTC group, the TC group showed more cohesive failures compared to the NTC mixed failure. Dual cure polymer based cement demonstrated higher bond strength and efficient adhesive bonding of the customized Zr post with root dentine compared to zinc phosphate (non-polymeric) and RMGIC (hybrid polymer). Thermocycling compromised Zr post adhesive bonding to root dentin.
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Affiliation(s)
- Khulud A. AlAali
- Department of Clinical Dental Sciences, College of Dentistry, Princess Nourah Bint Abdulrahman University, Riyadh 11671, Saudi Arabia
- Correspondence: (K.A.A.); (T.A.)
| | - Abdulaziz AlHelal
- Prosthetic Dental Science Department, College of Dentistry, King Saud University, Riyadh 11545, Saudi Arabia; (A.A.); (M.M.A.); (E.M.A.); (F.V.)
| | - Jawaher R. Almahri
- Prosthodontics Postgraduate Resident, College of Dentistry, Princess Nourah Bint Abdulrahman University, Riyadh 11671, Saudi Arabia;
| | - Aroob A. Albakri
- General Dentist, College of Dentistry, Princess Nourah Bint Abdulrahman University, Riyadh 11671, Saudi Arabia;
| | - Ragad M. Albani
- Prosthodontics Postgraduate Resident, College of Dentistry, King Saud University, Riyadh 11671, Saudi Arabia;
| | - Yasmeen A. Alhaizan
- Restorative Postgraduate Resident, King Faisal Specialist Hospital, Riyadh 11211, Saudi Arabia;
| | - Mai M. Alhamdan
- Prosthetic Dental Science Department, College of Dentistry, King Saud University, Riyadh 11545, Saudi Arabia; (A.A.); (M.M.A.); (E.M.A.); (F.V.)
| | - Naif A. Alaql
- Prosthodontic Department, Riyadh Specialized Dental Center, Ministry of Health, Riyadh 13226, Saudi Arabia;
| | - Mashael Binhasan
- Department of Restorative Dentistry, Division of Operative Dentistry, College of Dentistry, King Saud University, Riyadh 11545, Saudi Arabia;
| | - Eman M. Alhamdan
- Prosthetic Dental Science Department, College of Dentistry, King Saud University, Riyadh 11545, Saudi Arabia; (A.A.); (M.M.A.); (E.M.A.); (F.V.)
| | - Ahmed H. Albaqawi
- Department of Restorative Dental Science, College of Dentistry, University of Ha’il, Ha’il 55476, Saudi Arabia;
| | - Fahim Vohra
- Prosthetic Dental Science Department, College of Dentistry, King Saud University, Riyadh 11545, Saudi Arabia; (A.A.); (M.M.A.); (E.M.A.); (F.V.)
| | - Tariq Abduljabbar
- Prosthetic Dental Science Department, College of Dentistry, King Saud University, Riyadh 11545, Saudi Arabia; (A.A.); (M.M.A.); (E.M.A.); (F.V.)
- Correspondence: (K.A.A.); (T.A.)
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12
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Prospective Clinical Evaluation of Posterior Third-Generation Monolithic Zirconia Crowns Fabricated with Complete Digital Workflow: Two-Year Follow-Up. MATERIALS 2022; 15:ma15020672. [PMID: 35057389 PMCID: PMC8780337 DOI: 10.3390/ma15020672] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Revised: 01/06/2022] [Accepted: 01/13/2022] [Indexed: 12/11/2022]
Abstract
Clinical studies on the behavior of posterior translucent monolithic zirconia restorations are lacking. We assessed the clinical outcome and survival rate of posterior third-generation monolithic zirconia crowns over a 2-year period. A total of 24 patients, requiring 30 posterior full-contour restorations were selected. All abutments were scanned, and crowns were milled and cemented with a self-adhesive dual cure cement. Crowns were assessed using the California Dental Association’s criteria. Gingival status was assessed by evaluating the gingival index, plaque index, periodontal probing depth of the abutments and control teeth, and the margin index of the abutment teeth. Statistical analyses were performed using the Friedman and the Wilcoxon signed-rank tests. During the 2-year follow-up, no biological or mechanical complications were observed, and the survival and success rate was 100%. All restorations ranked as satisfactory throughout the follow-up period. The gingival index and plaque index were worse at the end of the 2-year follow-up. The margin index was stable during the 2 years of clinical service. No significant differences were recorded in periodontal parameters between crowns and control teeth. Third-generation monolithic zirconia could be a reliable alternative to posterior metal–ceramic and second-generation monolithic zirconia posterior crowns.
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13
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Ghavami-Lahiji M, Davalloo RT, Tajziehchi G, Shams P. Micro-computed tomography in preventive and restorative dental research: A review. Imaging Sci Dent 2022; 51:341-350. [PMID: 34987994 PMCID: PMC8695474 DOI: 10.5624/isd.20210087] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2021] [Revised: 07/04/2021] [Accepted: 07/09/2021] [Indexed: 01/15/2023] Open
Abstract
Purpose The use of micro-computed tomography (micro-CT) scans in biomedical and dental research is growing rapidly. This study aimed to explore the scientific literature on approaches and applications of micro-CT in restorative dentistry. Materials and Methods An electronic search of publications from January 2009 to March 2021 was conducted using ScienceDirect, PubMed, and Google Scholar. The search included only English-language articles. Therefore, only studies that addressed recent advances and the potential uses of micro-CT in restorative and preventive dentistry were selected. Results Micro-CT is a tool that enables 3-dimensional imaging on a small scale with very high resolution. In this method, there is no need for sample preparation or slicing. Therefore, it is possible to examine the internal structure of tissue and the internal adaptation of materials to surfaces without destroying them. Due to these advantages, micro-CT has been recommended as a standard imaging tool in dental research for many applications such as tissue engineering, endodontics, restorative dentistry, and research on the mineral density of hard tissues and bone growth. However, the high costs of micro-CT, the time necessary for scanning and reconstruction, computer expertise requirements, and the enormous volume of information are drawbacks. Conclusion The potential of micro-CT as an emerging, accurate, non-destructive approach is clear, and the valuable research findings reported in the literature provide an impetus for researchers to perform future studies focusing on employing this method in dental research.
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Affiliation(s)
- Mehrsima Ghavami-Lahiji
- Dental Sciences Research Center, School of Dentistry, Guilan University of Medical Sciences, Rasht, Iran.,Department of Restorative Dentistry, School of Dentistry, Guilan University of Medical Sciences, Rasht, Iran
| | - Reza Tayefeh Davalloo
- Department of Restorative Dentistry, School of Dentistry, Guilan University of Medical Sciences, Rasht, Iran
| | - Gelareh Tajziehchi
- Department of Restorative Dentistry, School of Dentistry, Guilan University of Medical Sciences, Rasht, Iran
| | - Paria Shams
- Department of Restorative Dentistry, School of Dentistry, Guilan University of Medical Sciences, Rasht, Iran
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14
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Jian Y, Zhang T, Wang X, Kyaw L, Pow EHN, Zhao K. Effect of supporting dies' mechanical properties on fracture behavior of monolithic zirconia molar crowns. Dent Mater J 2021; 41:249-255. [PMID: 34866116 DOI: 10.4012/dmj.2021-090] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The aim of this study was to investigate the effects of supporting dies with different mechanical properties on the fracture strengths and failure modes of monolithic zirconia crowns, and identify a suitable die material for testing high-strength ceramic restorations. Thirty six dies from teeth, porous titanium and composite-resin with 36 zirconia crowns were fabricated based on 3D model. Crowns were cemented, then underwent load-to-fracture testing. Fractographic analysis was performed with scanning electron microscopy, and finite element analysis was made. During loading, a high stress concentration zone formed near the loading point and on surface of die. Cracks generated on failure penetrated the crown and extended to die in 9 teeth group specimens, while composite-resin samples exhibited fracture of both crowns and dies. All dies remained intact in porous titanium group. Fracture mode was undistinguishable in all groups. It was concluded that porous titanium appears suitable as die material for dental restorations with high fracture strength.
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Affiliation(s)
- Yutao Jian
- Institute of Stomatological Research, Guangdong Provincial Key Laboratory of Stomatology, Sun Yat-Sen University
| | - Tianyi Zhang
- Research Center for Stomatology, Peking University Shenzhen Hospital
| | - Xiaodong Wang
- Department of Prosthodontics, Guanghua School of Stomatology, Sun Yat-Sen University; Guangdong Engineering Research Center of Technology and Materials for Oral Reconstruction, Guangdong Provincial Key Laboratory of Stomatology
| | - Laina Kyaw
- Department of Prosthodontics, Guanghua School of Stomatology, Sun Yat-Sen University; Guangdong Engineering Research Center of Technology and Materials for Oral Reconstruction, Guangdong Provincial Key Laboratory of Stomatology
| | - Edmond Ho Nang Pow
- Prosthodontics, Faculty of Dentistry, The University of Hong Kong, Prince Philip Dental Hospital
| | - Ke Zhao
- Department of Prosthodontics, Guanghua School of Stomatology, Sun Yat-Sen University; Guangdong Engineering Research Center of Technology and Materials for Oral Reconstruction, Guangdong Provincial Key Laboratory of Stomatology
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15
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Indergård JA, Skjold A, Schriwer C, Øilo M. Effect of cementation techniques on fracture load of monolithic zirconia crowns. Biomater Investig Dent 2021; 8:160-169. [PMID: 34693294 PMCID: PMC8530494 DOI: 10.1080/26415275.2021.1990764] [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: 11/28/2022] Open
Abstract
Aim The aim of this study was to evaluate the effect of cement on the fracture load of monolithic zirconia crowns with different yttria content (3 and 5 mol%). Methods A total of 62 monolithic zirconia crowns, 40 3Y-zirconia crowns (Prettau® Zirconia, Zirkonzahn) and 22 5Y-zirconia crowns (Prettau® 4 Anterior®, Zirkonzahn) were produced to a shallow chamfer molar preparation. The 3Y-crowns were divided into four groups and attached to composite abutment duplicates (SDR® flow+, Dentsply DeTrey GmbH) using the following four cementation techniques; (1) Self-adhesive resin-based cement, (2) Pre-treatment with air-abrasion and self-adhesive resin-based cement, (3) Zinc phosphate cement, (4) Glass-ionomer cement. The 5Y-crowns were divided into two groups and attached to the duplicates with; (1) Self-adhesive resin-based cement, or (2) Air-abrasion pre-treatment and self-adhesive resin-based cement. All crowns were loaded axially (0.5 mm/min) on the occlusal surface until fracture occurred. Results Among the 3Y-zirconia groups, the zinc phosphate cement group fractured at lower loads compared to the resin-based cement groups, with and without air-abrasion, (p < .012). Among the 5Y-groups the air-abraded crowns fractured at statistically significant lower loads compared to the untreated crowns (p < .028). Load at fracture values were significantly different between the two zirconia materials (p < .001), with fracture loads ranging from 3873 to 7500 N in the 3Y-groups, and 2100 to 4948 N in the 5Y-groups. Conclusions Resin-based cementation increased the fracture load compared to non-adhesive cementation. The 3Y-crowns fractured at almost twice the loads of the 5Y-crowns. Pre-treatment with air abrasion reduced the strength of the 5Y-crowns only, showing the importance of differentiating the treatment of the two materials.
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Affiliation(s)
- Janne Angen Indergård
- Faculty of Medicine, Department of Clinical Dentistry, University of Bergen, Bergen, Norway
| | - Anneli Skjold
- Faculty of Medicine, Department of Clinical Dentistry, University of Bergen, Bergen, Norway
| | - Christian Schriwer
- Faculty of Medicine, Department of Clinical Dentistry, University of Bergen, Bergen, Norway
| | - Marit Øilo
- Faculty of Medicine, Department of Clinical Dentistry, University of Bergen, Bergen, Norway
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16
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Sadeqi HA, Baig MR, Al-Shammari M. Evaluation of Marginal/Internal Fit and Fracture Load of Monolithic Zirconia and Zirconia Lithium Silicate (ZLS) CAD/CAM Crown Systems. MATERIALS 2021; 14:ma14216346. [PMID: 34771872 PMCID: PMC8585271 DOI: 10.3390/ma14216346] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/18/2021] [Revised: 10/15/2021] [Accepted: 10/20/2021] [Indexed: 11/24/2022]
Abstract
Fit accuracy and fracture strength of milled monolithic zirconia (Zi) and zirconia-reinforced lithium silicate (ZLS) crowns are important parameters determining the success of these restorations. This study aimed to evaluate and compare the marginal and internal fit of monolithic Zi and ZLS crowns, along with the fracture load, with and without mechanical aging. Thirty-two stone dies acquired from a customized master metal molar die were scanned, and ceramic crowns (16 Zi Ceramill Zolid HT+ and 16 ZLS Vita Suprinity) were designed and milled. Absolute marginal discrepancies (AMD), marginal gaps (MG), and internal gaps (IG) of the crowns, in relation to the master metal die, were evaluated using x-ray nanotomography (n = 16). Next, thirty-two metal dies were fabricated based on the master metal die, and crowns (16 Zi; 16 ZLS) cemented and divided into four groups of eight each; eight Zi with mechanical aging (MA), eight Zi without mechanical aging (WMA), eight ZLS (MA), and eight ZLS (WMA). Two groups of crowns (Zi-MA; ZLS-MA) were subjected to 500,000 mechanical cycles (200 ± 50 N, 10 Hz) followed by axial compressive strength testing of all crowns, until failure, and the values were recorded. Independent sample t tests (α = 0.05) revealed no significant differences between Zi and ZLS crowns (p > 0.05); for both internal and marginal gaps, however, there were significant differences in AMD (p < 0.005). Independent samples Mann–Whitney U and Kruskal–Wallis tests revealed significant differences between the two materials, Zi and ZLS, regardless of fatigue loading, and for the individual material groups based on aging (α = 0.05). Multiple comparisons using Bonferroni post-hoc analysis showed significant differences between Zi and ZLS material groups, with or without aging. Within the limitations of this study, the ZLS crown fit was found to be on par with Zi, except for the AMD parameter. As regards fracture resistance, both materials survived the normal range of masticatory forces, but the Zi crowns demonstrated greater resistance to fracture. The monolithic Zi and ZLS crowns seem suitable for clinical application, based on the fit and fracture strength values obtained.
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Affiliation(s)
- Haneen A. Sadeqi
- Department of Bioclinical Sciences, Faculty of Dentistry, Kuwait University, P.O. Box 24923,
Safat 13110, Kuwait; (H.A.S.); (M.A.-S.)
| | - Mirza Rustum Baig
- Department of Restorative Sciences (Prosthodontics), Faculty of Dentistry, Kuwait University, P.O. Box 24923,
Safat 13110, Kuwait
- Correspondence:
| | - Mohammad Al-Shammari
- Department of Bioclinical Sciences, Faculty of Dentistry, Kuwait University, P.O. Box 24923,
Safat 13110, Kuwait; (H.A.S.); (M.A.-S.)
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Sakrana AA, Al-Zordk W, El-Sebaey H, Elsherbini A, Özcan M. Does Preheating Resin Cements Affect Fracture Resistance of Lithium Disilicate and Zirconia Restorations? MATERIALS 2021; 14:ma14195603. [PMID: 34640000 PMCID: PMC8509625 DOI: 10.3390/ma14195603] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/08/2021] [Revised: 09/20/2021] [Accepted: 09/23/2021] [Indexed: 11/22/2022]
Abstract
This paper assesses the impact of preheating of adhesive cement on the fracture resistance of lithium disilicate and zirconia restorations. Methods: A total of 80 human maxillary premolar teeth were assigned into 8 groups (n = 10) according to material type (either lithium disilicate or zirconia) and type of resin cement (either LinkForce or Panavia SA) with preheating temperature at 54 °C or at room temperature (25 °C). Teeth were prepared and restored with either lithium disilicate or zirconia restorations. After cementation, specimens were thermal cycled (10,000 cycles, 5 °C/55 °C), then load cycled for 240,000 cycles (50 N). Each specimen was statically loaded until fracture and the load (N) at fracture was recorded, then the failure mode was detected. Statistical analysis of data was performed (p ≤ 0.05). Results: There was no significant difference (p = 0.978) in fracture mean values between LinkForce and Panavia SA. Statistically significant difference (p = 0.001) was revealed between fracture resistance of lithium disilicate restorations cemented with LinkForce at 25 °C and at 54 °C; however there was no significant difference (p = 0.92) between the fracture resistance of lithium disilicate restorations cemented with Panavia SA used at 25 °C and at 54 °C. Regarding the interaction between ceramic material, cement type, and cement preheating, there was no significant effect (p > 0.05) in fracture resistance. The cement type does not influence the fracture resistance of ceramic restorations. Preheating of resin cement has negatively influenced the fracture resistance of all tested groups, except for lithium disilicate cemented using LinkForce cement.
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Affiliation(s)
- Amal Abdelsamad Sakrana
- Fixed Prosthodontics Department, Faculty of Dentistry, Mansoura University, Mansoura 35516, Egypt; (W.A.-Z.); (H.E.-S.)
- Fixed Prosthodontics Department, Faculty of Dentistry, Horus University, Damietta 34511, Egypt
- Correspondence: ; Tel.: +20-102-384-9099
| | - Walid Al-Zordk
- Fixed Prosthodontics Department, Faculty of Dentistry, Mansoura University, Mansoura 35516, Egypt; (W.A.-Z.); (H.E.-S.)
- Fixed Prosthodontics Department, Faculty of Dentistry, Horus University, Damietta 34511, Egypt
| | - Heba El-Sebaey
- Fixed Prosthodontics Department, Faculty of Dentistry, Mansoura University, Mansoura 35516, Egypt; (W.A.-Z.); (H.E.-S.)
- Fixed Prosthodontics Department, Faculty of Dentistry, Horus University, Damietta 34511, Egypt
| | | | - Mutlu Özcan
- Division of Dental Biomaterials, Center for Dental and Oral Medicine, Clinic for Reconstructive Dentistry, University of Zurich, 8032 Zurich, Switzerland;
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18
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Øilo M, Haugli K, Rønold HJ, Ulsund AH, Ruud A, Kvam K. Pre-cementation procedures' effect on dental zirconias with different yttria content. Dent Mater 2021; 37:1425-1436. [PMID: 34330519 DOI: 10.1016/j.dental.2021.07.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2020] [Revised: 04/26/2021] [Accepted: 07/07/2021] [Indexed: 11/30/2022]
Abstract
OBJECTVE Several pre-cementation procedures have been advocated to enhance adhesion between zirconia and resin-based cement. There is, however, limited documentation on how these pre-treatments affect the strength of zirconia crowns as most tests are performed on discs or bars. The aim was to assess the effect of pre-cementation procedures on fracture mode, fracture strength and cement retention on zirconia. METHODS Two dental zirconia materials with different yttria content were assessed (<4 and>5 mol%). Both discs (n = 45) and crown-shaped specimens (n = 30) of the two materials were pretreated with either air-abrasion or hot-etching with KHF2 and compared with untreated controls with regards to surface roughness, crystallography, wettability, cement adhesion and fracture strength. RESULTS AND SIGNIFICANCE Air-abrasion improves adhesion and strength of zirconia with moderate yttria content (<4 mol%). Acid etching with heated KHF2 showed the best effect on strength and cement retention on zirconia with higher yttria content (>5 mol%). Application of KHF2 was, however, complicated on crown-shaped specimens. Pre-treatment and cementation protocols should be optimized for different dental zirconias to improve both strength and retention.
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Affiliation(s)
- Marit Øilo
- NIOM, Nordic Institute of Dental Materials, Oslo, Norway; Department of Clinical Dentistry, Faculty of Medicine, University of Bergen, Bergen, Norway.
| | - Ketil Haugli
- NIOM, Nordic Institute of Dental Materials, Oslo, Norway; OSLOMET, Oslo Metropolitan University, Oslo, Norway
| | - Hans Jacob Rønold
- NIOM, Nordic Institute of Dental Materials, Oslo, Norway; Department of Clinical Dentistry, Faculty of Dentistry, University of Oslo, Oslo, Norway
| | - Amanda H Ulsund
- Department of Clinical Dentistry, Faculty of Dentistry, University of Oslo, Oslo, Norway
| | - Amund Ruud
- NIOM, Nordic Institute of Dental Materials, Oslo, Norway
| | - Ketil Kvam
- NIOM, Nordic Institute of Dental Materials, Oslo, Norway
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19
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Schriwer C, Gjerdet NR, Arola D, Øilo M. The effect of preparation taper on the resistance to fracture of monolithic zirconia crowns. Dent Mater 2021; 37:e427-e434. [PMID: 33910755 DOI: 10.1016/j.dental.2021.03.012] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2020] [Revised: 03/15/2021] [Accepted: 03/28/2021] [Indexed: 10/21/2022]
Abstract
OBJECTIVE Monolithic zirconia crowns have become a viable alternative to conventional layered restorations. The aim of this study was to evaluate whether the taper, and thus wall thickness, of the abutment or pre-defined cement space affect the fracture resistance or fracture mode of monolithic zirconia crowns. METHODS A model tooth was prepared with a taper of 15° and a shallow circumferential chamfer preparation (0.5 mm). Two additional models were made based on the master model with a taper of 10° and 30° using computer-aided design software. Twenty monolithic 3rd generation translucent zirconia crowns were produced for each model with pre-defined cement space set to either 30 μm or 60 μm (n = 60). The estimated cement thickness was assessed by the replica method. The cemented crowns were loaded centrally in the occlusal fossa at 0.5 mm/min until fracture. Fractographic analyses were performed on all fractured crowns. RESULTS The load at fracture was statistically significant different between the groups (p < 0.05). The crowns with 30° taper fractured at lower loads than those with 10° and 15° taper, regardless of the cement space (p < 0.05). The fracture origin for 47/60 crowns (78%) was in the cervical area, close to the top of the curvature in the mesial or distal crown margin. The remaining fractures started at the internal surface of the occlusal area and propagated cervically. SIGNIFICANCE The fracture resistance of the monolithic zirconia crowns was lower for crowns with very large taper compared to 10 and 15° taper even though the crown walls were thicker.
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Affiliation(s)
- Christian Schriwer
- Department of Clinical Dentistry, Faculty of Medicine, University of Bergen, Norway.
| | - Nils Roar Gjerdet
- Department of Clinical Dentistry, Faculty of Medicine, University of Bergen, Norway
| | - Dwayne Arola
- Materials Science and Engineering, University of Washington, USA; Department of Restorative Dentistry, Dental School, University of Washington, USA
| | - Marit Øilo
- Department of Clinical Dentistry, Faculty of Medicine, University of Bergen, Norway
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20
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Ansarifard E, Panbehzan Z, Giti R. Evaluation of microhardness and water sorption/solubility of dual-cure resin cement through monolithic zirconia in different shades. J Indian Prosthodont Soc 2021; 21:50-56. [PMID: 33835068 PMCID: PMC8061437 DOI: 10.4103/jips.jips_284_20] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Aim: The objective is to evaluate the effect of shades of monolithic zirconia on the microhardness and sorption/solubility of the underlying two dual-cured resin types of cement. Materials and Methods: Eighty samples of two dual-cured resin cement discs were polymerized under 60 monolithic zirconia discs in three shades and directly activated resin discs of cement were used as the control group (n = 10). After 24 h storage at 37°C in an incubator, Vickers microhardness and the sorption and solubility were measured. Statistical Analysis Used: Two-way ANOVA , one-way ANOVA, Independent t-test, Tukey's honestly significant difference, and Tamhane's T2 tests. Results: The mean microhardness of the Variolink N resin cements were significantly higher than Panavia SA ones (P < 0.001). Furthermore, Variolink N cements exhibited lower sorption/solubility than Panavia SA resin cements (both P < 0.05). The ceramic shade had a significant influence on the microhardness of both cements (P < 0.001) but had no significant effect on the sorption/solubility of resin cements (P > 0.05). Conclusion: Interposition of monolithic zirconia decreases the microhardness of resin cement especially Panavia SA. In Variolink N, by increasing the chroma saturation of ceramics, the microhardness decreased, however in Panavia SA, it was altered by the shades, but not in a specific pattern. For both cements, there were no statistical differences between the sorption/solubility of samples photo-cured under different shades. There was a reverse correlation between microhardness and water sorption/solubility of both cements.
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Affiliation(s)
- Elham Ansarifard
- Department of Prosthodontics, School of Dentistry, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Zahra Panbehzan
- Department of Prosthodontics, School of Dentistry, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Rashin Giti
- Department of Prosthodontics, School of Dentistry, Shiraz University of Medical Sciences, Shiraz, Iran
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21
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Rohr N, Märtin S, Fischer J. Fracture load of zirconia implant supported CAD/CAM resin crowns and mechanical properties of restorative material and cement. J Prosthodont Res 2021; 65:502-508. [PMID: 33840705 DOI: 10.2186/jpr.jpr_d_20_00051] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
PURPOSE To test if resin CAD/CAM materials should be considered for zirconia implants and how their mechanical properties affect the fracture load. METHODS Fracture load of molar crowns of CAD/CAM materials (VITA CAD-Temp [CT], Cerasmart [CS], Lava Ultimate [LU], Pekkton Ivory [PK]) on zirconia implants (ceramic.implant, 4.0 mm) fixed either with no cement, temporary cement (Harvard Implant semi-permanent [HIS]), self-adhesive (VITA Adiva S-Cem [VAS]) or either one of two adhesive cements (Multilink Automix [MLA], VITA Adiva F-Cem [VAF]) was analyzed. The restorative materials were characterized by their flexural strength, fracture toughness, elemental composition and organic/inorganic ratio while compressive strength of the cements was measured. RESULTS For the fracture load significantly highest mean values were fo und overall for PK (2921 ±300 N) > LU (2017 ±499 N) > CS (1463 ±367 N) = CT (1451 ±327 N) (p > 0.05). When analyzing the effect of the cement on the fracture load the overall ranking was VAF (2245 ±650 N) ≥ MLA (2188 ±708 N) ≥ VAS (2017 ±563 N) > HIS (1757 ±668 N) = no cement (1595 ±757 N) (p <0.05), meaning fracture load increased with the compressive strength of the cements. Additionally, a linear trend was found between the fracture load and the fracture toughness of the restorative materials. CONCLUSIONS All restorative materials exhibited fracture load values similar or higher than lithium disilicate tested previously. Fracture load of CT, CS and LU can be significantly increased when an adhesive cement with a high compressive strength is used.
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Affiliation(s)
- Nadja Rohr
- Biomaterials and Technology, Department of Reconstructive Dentistry, University Center for Dental Medicine, University of Basel, Basel
| | - Sabrina Märtin
- Biomaterials and Technology, Department of Reconstructive Dentistry, University Center for Dental Medicine, University of Basel, Basel
| | - Jens Fischer
- Biomaterials and Technology, Department of Reconstructive Dentistry, University Center for Dental Medicine, University of Basel, Basel
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Tokita C, Maeno M, Nara Y. The effect of space setting values and restorative block materials on the bonding of metal-free CAD/CAM onlay restorations. Dent Mater J 2021; 40:994-1006. [PMID: 33827999 DOI: 10.4012/dmj.2020-293] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The effects of space setting values and restorative materials on the bonding of metal-free CAD/CAM onlay restoration were examined quantitatively and qualitatively. Seventy-two standardized MODB onlay cavities, prepared using human molars were restored under nine conditions, based on three space setting values, Increased (IC), Standard (SC, control), Decreased (DC), and three restorative block materials, resin-composites (RC), lithium disilicate glass-ceramics (LD), Feldspar ceramics (FC, control). All the restored specimens were subjected to cyclic loading and thereafter the microtensile bond strength (µ-TBS) was measured and analyzed statistically. The effect of space setting value on the µ-TBS varied with the restorative material. The bonding reliability of RC and the bonding durability of LD were significantly superior to FC. The bonding characteristics of RC under IC and DC were similar to those under SC. LD under DC and FC under IC were effective in obtaining an excellent bonding reliability relative to their SC.
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Affiliation(s)
- Chie Tokita
- Department of Adhesive Dentistry, School of Life Dentistry at Tokyo, The Nippon Dental University
| | - Masahiko Maeno
- Department of Adhesive Dentistry, School of Life Dentistry at Tokyo, The Nippon Dental University
| | - Yoichiro Nara
- Department of Adhesive Dentistry, School of Life Dentistry at Tokyo, The Nippon Dental University
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23
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杨 欣, 李 榕, 叶 红, 陈 虎, 王 勇, 周 永, 孙 玉. [Evaluation of fracture strength of two kinds of zirconia all-ceramic crowns with different edge compensation angles]. BEIJING DA XUE XUE BAO. YI XUE BAN = JOURNAL OF PEKING UNIVERSITY. HEALTH SCIENCES 2021; 53:402-405. [PMID: 33879918 PMCID: PMC8072427 DOI: 10.19723/j.issn.1671-167x.2021.02.028] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 02/22/2019] [Indexed: 06/12/2023]
Abstract
OBJECTIVE To evaluate the effects of different edge compensation angles on the fracture strength of multilayer zirconia all-ceramic crowns and traditional uniform zirconia all-ceramic crowns. METHODS The resin tooth preparation specimen of the mandibular first molar with a knife-edge was fabricated. A 3D digital model of the specimen was obtained by scanning it with a 3D dental model scanner. The 3D digital model was imported into computer aided design (CAD) software, and three 3D digital models of the full crown with the same surface shape are designed with the edge compensation angles of 30°, 45° and 60°, respectively. Then, the designed 3D digital model is imported into computer aided manufacturing (CAM) software. Three kinds of multilayer and homogeneous zirconia all-porcelain crowns with different edge compensation angles were fabricated, 10 each for a total of 60. The fracture load of each crown was measured under the electronic universal testing machine. RESULTS Fracture load of multilayer and uniform zirconia all-ceramic crowns, (4 322.86±610.07) N and (5 914.12±596.80) N in the 30° group, (5 264.82±883.76) N and (5 220.83±563.38) N in the 45° group and (4 900.42±345.41) N and (5 050.22±560.24) N in the 60° group, respectively. The fracture load of multi-layer zirconia all-ceramic crowns in the 30° group was significantly lower than that of homogeneous zirconia all-ceramic crowns(P < 0.05); there was no statistical significance in 45° group and 60° group(P>0.05). In the multi-layer zirconia all-ceramic crowns: the fracture load of the 30° group was significantly lower than that of the 45° group (P < 0.05); there was no significant difference between the 30° group and the 60° group, the 45° group and the 60° group (P>0.05).In uniform zirconia full crown group: the 30° group was higher than the 45° group, the 30° group was higher than the 60° group (P < 0.05), and there was no significant difference between the 45° group and the 60° group (P>0.05). CONCLUSION The fracture loads of three kinds of uniform and multilayer zirconia all ceramic crowns with different edge compensation angles can meet the clinical requirements. A smaller edge compensation angle is recommended when using traditional zirconia all-ceramic crowns, while 45° is recommended when using multi-layer zirconia all-ceramic crowns.
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Affiliation(s)
- 欣 杨
- 北京大学口腔医学院·口腔医院,修复科 国家口腔疾病临床医学研究中心 口腔数字化医疗技术和材料国家工程实验室 口腔数字医学北京市重点实验室,北京 100081Department of Prosthodontics, Peking University School and Hospital of Stomatology & National Clinical Research Center for Oral Diseases & National Engineering Laboratory for Digital and Material Technology of Stomatology & Beijing Key Laboratory of Digital Stomatology, Beijing 100081, China
| | - 榕 李
- 北京大学口腔医学院·口腔医院,口腔医学数字化研究中心 国家口腔疾病临床医学研究中心 口腔数字化医疗技术和材料国家工程实验室 口腔数字医学北京市重点实验室,北京 100081Center for Digital Dentistry, Peking University School and Hospital of Stomatology & National Clinical Research Center for Oral Diseases & National Engineering Laboratory for Digital and Material Technology of Stomatology & Beijing Key Laboratory of Digital Stomatology, Beijing 100081, China
| | - 红强 叶
- 北京大学口腔医学院·口腔医院,修复科 国家口腔疾病临床医学研究中心 口腔数字化医疗技术和材料国家工程实验室 口腔数字医学北京市重点实验室,北京 100081Department of Prosthodontics, Peking University School and Hospital of Stomatology & National Clinical Research Center for Oral Diseases & National Engineering Laboratory for Digital and Material Technology of Stomatology & Beijing Key Laboratory of Digital Stomatology, Beijing 100081, China
| | - 虎 陈
- 北京大学口腔医学院·口腔医院,口腔医学数字化研究中心 国家口腔疾病临床医学研究中心 口腔数字化医疗技术和材料国家工程实验室 口腔数字医学北京市重点实验室,北京 100081Center for Digital Dentistry, Peking University School and Hospital of Stomatology & National Clinical Research Center for Oral Diseases & National Engineering Laboratory for Digital and Material Technology of Stomatology & Beijing Key Laboratory of Digital Stomatology, Beijing 100081, China
| | - 勇 王
- 北京大学口腔医学院·口腔医院,口腔医学数字化研究中心 国家口腔疾病临床医学研究中心 口腔数字化医疗技术和材料国家工程实验室 口腔数字医学北京市重点实验室,北京 100081Center for Digital Dentistry, Peking University School and Hospital of Stomatology & National Clinical Research Center for Oral Diseases & National Engineering Laboratory for Digital and Material Technology of Stomatology & Beijing Key Laboratory of Digital Stomatology, Beijing 100081, China
| | - 永胜 周
- 北京大学口腔医学院·口腔医院,修复科 国家口腔疾病临床医学研究中心 口腔数字化医疗技术和材料国家工程实验室 口腔数字医学北京市重点实验室,北京 100081Department of Prosthodontics, Peking University School and Hospital of Stomatology & National Clinical Research Center for Oral Diseases & National Engineering Laboratory for Digital and Material Technology of Stomatology & Beijing Key Laboratory of Digital Stomatology, Beijing 100081, China
| | - 玉春 孙
- 北京大学口腔医学院·口腔医院,口腔医学数字化研究中心 国家口腔疾病临床医学研究中心 口腔数字化医疗技术和材料国家工程实验室 口腔数字医学北京市重点实验室,北京 100081Center for Digital Dentistry, Peking University School and Hospital of Stomatology & National Clinical Research Center for Oral Diseases & National Engineering Laboratory for Digital and Material Technology of Stomatology & Beijing Key Laboratory of Digital Stomatology, Beijing 100081, China
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Does Printing Orientation Matter? In-Vitro Fracture Strength of Temporary Fixed Dental Prostheses after a 1-Year Simulation in the Artificial Mouth. MATERIALS 2021; 14:ma14020259. [PMID: 33430271 PMCID: PMC7825647 DOI: 10.3390/ma14020259] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/10/2020] [Revised: 01/04/2021] [Accepted: 01/04/2021] [Indexed: 02/07/2023]
Abstract
Computer-aided design and computer-aided manufacturing (CAD–CAM) enable subtractive or additive fabrication of temporary fixed dental prostheses (FDPs). The present in-vitro study aimed to compare the fracture resistance of both milled and additive manufactured three-unit FDPs and bar-shaped, ISO-conform specimens. Polymethylmethacrylate was used for subtractive manufacturing and a light-curing resin for additive manufacturing. Three (bars) and four (FDPs) different printing orientations were evaluated. All bars (n = 32) were subjected to a three-point bending test after 24 h of water storage. Half of the 80 FDPs were dynamically loaded (250,000 cycles, 98 N) with simultaneous hydrothermal cycling. Non-aged (n = 40) and surviving FDPs (n = 11) were subjected to static loading until fracture. Regarding the bar-shaped specimens, the milled group showed the highest flexural strength (114 ± 10 MPa, p = 0.001), followed by the vertically printed group (97 ± 10 MPa, p < 0.007). Subtractive manufactured FDPs revealed the highest fracture strength (1060 ± 89 N) with all specimens surviving dynamic loading. During artificial aging, 29 of 32 printed specimens failed. The present findings indicate that both printing orientation and aging affect the strength of additive manufactured specimens. The used resin and settings cannot be recommended for additive manufacturing of long-term temporary three-unit FDPs.
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Al Mortadi N, Bataineh K, Al Janaideh M. <p>Fatigue Failure Load of Molars with Thin-Walled Prosthetic Crowns Made of Various Materials: A 3D-FEA Theoretical Study</p>. Clin Cosmet Investig Dent 2020; 12:581-593. [PMID: 33376410 PMCID: PMC7759726 DOI: 10.2147/ccide.s286826] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2020] [Accepted: 11/21/2020] [Indexed: 01/22/2023] Open
Affiliation(s)
- Noor Al Mortadi
- Department of Applied Dental Sciences, Jordan University of Science and Technology, Irbid, Jordan
- Correspondence: Noor Al Mortadi Department of Applied Dental Sciences, Jordan University of Science and Technology, P.O. Box (3030), Irbid22110, JordanTel +9627201000 Email
| | - Khaled Bataineh
- Department of Mechanical Engineering, Jordan University of Science and Technology, Irbid, Jordan
| | - Mohammad Al Janaideh
- Department of Mechanical Engineering, Jordan University of Science and Technology, Irbid, Jordan
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Juntavee N, Juntavee A, Kornrum S. Influence of Margin Designs on Crack Initiation of High Translucency Monolithic Zirconia Crowns. J Prosthodont 2020; 30:490-499. [PMID: 33009879 DOI: 10.1111/jopr.13269] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/01/2020] [Indexed: 11/29/2022] Open
Abstract
PURPOSE Zirconia crowns often crack at the margin. This study determined the loads and the times at which cracks are initiated in high-translucency monolithic zirconia crowns with different margin designs. MATERIALS AND METHODS A total of 90 crowns were fabricated from Zirconia blanks. The fabricated crowns had different margin thicknesses (light-chamfer, CL and heavy-chamfer, CH ) and collar heights (no-collar, NC ; low-collar, LC ; high-collar, HC ). They were grouped as CL NC , CL LC , CL HC , CH NC , CH LC , and CH HC (15 crowns/group). The crowns were seated on a metal model and loaded vertically through round end punch (Φ = 10 mm) at 0.2 mm/min crosshead speed until cracks began to be seen. Videos of the crack initiation were recorded at the rate of 50 frames/second. Load-initiated cracks and durability time were compared for significant differences using analysis of variance. RESULTS The mean ± standard deviation values of load (N) and time (s) taken to initiate cracks were 3190 ±775, 212 ±47 for CL NC ; 2754 ±1109, 180 ±42 for CL LC ; 2887±832, 191±27 for CL HC ; 4082 ±896, 241 ±36 for CH NC ; 4180 ±1029, 220 ±28 for CH LC ; 4119 ±1124, 222 ±39 for CH HC . This indicates that the thickness of the margin has a significant influence on load-withstanding crack initiation capacity and durability time (p < 0.05). No significant impact of collar height was observed on either load-withstanding capacity or durability time (p > 0.05). No interaction was observed among these factors. CONCLUSION Heavy chamfer margin provided a stronger zirconia crown than the light chamfer margin, but both of them were capable of withstanding crack-initiated load higher than the theoretical maximum masticatory force. The presence or absence of a collar did not have any impact on the crack initiation. Fabrication of zirconia crowns with either a heavy or light chamfer margin and with or without the presence of a collar should be generated by considering the relevant emergence profile.
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Affiliation(s)
- Niwut Juntavee
- Department of Prosthodontics, Faculty of Dentistry, Khon Kaen University, Khon Kaen, Thailand
| | - Apa Juntavee
- Division of Pediatric Dentistry, Department of Preventive Dentistry, Faculty of Dentistry, Khon Kaen University, Khon Kaen, Thailand
| | - Sasiprapa Kornrum
- Division of Biomaterials and Prosthodontics Research, Faculty of Dentistry, Khon Kaen University, Khon Kaen, Thailand
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Effect of Marginal Designs on Fracture Strength of High Translucency Monolithic Zirconia Crowns. Int J Dent 2020; 2020:8875609. [PMID: 32831840 PMCID: PMC7421695 DOI: 10.1155/2020/8875609] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Revised: 07/04/2020] [Accepted: 07/14/2020] [Indexed: 11/18/2022] Open
Abstract
Introduction Monolithic zirconia is able to achieve certain aesthetic, but its durability in resisting fracture has been questioned, as fractures often originate from margins of restoration. This study determined fracture resistance of highly translucent monolithic zirconia crowns with different margin designs in terms of marginal thickness and collar height. Materials and Methods Zirconia blanks (Ceramill® Zolid HT+) were selected for the fabrication of zirconia crowns according to different designs, including varying margin thicknesses (light chamfer, CL; heavy chamfer, CH) and collar heights (no collar, NC; low collar, LC; high collar, HC), which resulted in CLNC, CLLC, CLHC, CHNC, CHLC, and CHHC groups (15 crowns each). The crowns were seated on a metal die and loaded vertically through round end punch (θ = 10 mm), contacting with inclined planes of cusp in a testing machine with crosshead speed of 0.2 mm/min until fracture. Videos with a rate of 50 frames/second were used to record fracture. Fracture load (N) and durable period (s) were compared for significant differences using ANOVA and Bonferroni test (α = 0.05). Results The mean ± sd of fracture load (N) and durable time (s) were 3211 ± 778 and 212 ± 47 for CLNC; 3041 ± 1370 and 188 ± 53 for CLLC; 2913 ± 828 and 192 ± 27 for CLHC; 4226 ± 905 and 245 ± 35 for CHNC; 4486 ± 807 and 228 ± 29 for CHLC; and 4376 ± 1043 and 227 ± 37 for CHHC. This indicated that marginal thickness had a significant influence on load-bearing capacity and durable time (p < 0.05). No significant impact of collar height was shown, either on load-bearing capacity or durable time (p > 0.05). No interaction between two factors was presented (p > 0.05). Conclusions Heavy chamfer margin provided stronger zirconia crown than light chamfer, but both were capable of withstanding fracture load higher than maximum masticatory force. Neither presence nor absence of collar indicated any impact on strength. Fabrication of zirconia crowns with either heavy or light chamfer margin and either presence or absence of collar, with the consideration of emergence profile, should be considered.
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Azab MM, Moheb DM, El Shahawy OI, Rashed MAM. Influence of luting cement on the clinical outcomes of Zirconia pediatric crowns: A 3-year split-mouth randomized controlled trial. Int J Paediatr Dent 2020; 30:314-322. [PMID: 31845435 DOI: 10.1111/ipd.12607] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/20/2019] [Revised: 12/09/2019] [Accepted: 12/09/2019] [Indexed: 11/30/2022]
Abstract
BACKGROUND There is no scientific evidence supporting the choice of luting cement for cementation of zirconia crowns. AIM The purpose of this split-mouth study was to compare the efficacy of using bioactive cement versus packable glass ionomer for cementation of posterior pediatric zirconia crowns. DESIGN Fifty first mandibular primary molars were restored by zirconia crowns and were randomly divided to be luted with either (a) bioactive cement or (b) packable glass ionomer. Crowns' retention, fracture, and gingival condition were evaluated at 1 week, and 1-, 3-, 6-, 9-, 12-, 18-, 24-, and 36-month intervals. Statistical analysis was carried out using Fisher's exact test, Kaplan-Meier survival analysis, and Wilcoxon signed rank test. RESULTS At 3- to 36-month follow-ups, there were statistically significant (P = .009-≤.001) less debonded crowns in packable glass ionomer group. There were no fractured crowns for either cements. There was no statistically significant difference between gingival index scores. CONCLUSIONS Packable glass ionomer is more retentive than bioactive cement when used for cementing zirconia pediatric crowns. Posterior zirconia pediatric crowns have high fracture resistance after 36 months of clinical performance, irrespective of luting cement. Luting cement for zirconia pediatric crowns has no apparent effect on gingival condition around crowns.
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Affiliation(s)
- Maha Moussa Azab
- Department of Pediatric Dentistry, Faculty of Dentistry, Fayoum University, Egypt
| | - Dalia Mohamed Moheb
- Department of Pediatric Dentistry, Faculty of Dentistry, Cairo University, Egypt
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Svanborg P, Hjalmarsson L. A systematic review on the accuracy of manufacturing techniques for cobalt chromium fixed dental prostheses. Biomater Investig Dent 2020; 7:31-40. [PMID: 32083253 PMCID: PMC7006738 DOI: 10.1080/26415275.2020.1714445] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2019] [Accepted: 12/22/2019] [Indexed: 11/11/2022] Open
Abstract
Purpose To compare the fit and assess the accuracy of tooth-supported single and multi-unit FDPs in cobalt chromium fabricated using different manufacturing techniques. Materials and methods A systematic search was performed in three databases; PubMed, Scopus, and Web of Science, using clearly specified search terms and inclusion criteria. The search yielded 1071 articles and included 18 articles in the analysis. Data regarding the fit analyses and the methods of manufacturing were extracted and the accuracy was defined as the fit result minus the pre-set cement spacer. Internal gap (IntG) was the mean of all the internal measuring points and total gap (TotG) was the mean of all measuring points (marginal, cervical, chamfer, axial, occlusal). Results The total gap results for fit and accuracy irrespective of manufacturing technique were 96 μm and 54 μm for single crowns, 107 μm and 54 μm for multi-unit FDPs, and 98 μm and 54 μm for both single crowns and multi-unit FDPs combined. For total gap of single crowns soft milling had the highest accuracy, for multi-unit FDPs additive manufactured restorations had the highest accuracy. With the results grouped by impression technique, the accuracy for total gap was highest for digital impressions and lower for conventional impressions. Conclusions Due to the inherent limitations of this systematic review, it still remains unclear what effect the manufacturing technique has on the fit of FDPs. However, the descriptive results suggest that the marginal fit of cobalt chromium FDPs is not negatively affected by the manufacturing technique.
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Affiliation(s)
- Per Svanborg
- Department of Prosthodontics/Dental Materials Science, Institute of Odontology, Sahlgrenska Academy, University of Gothenburg, Göteborg, Sweden
| | - Lars Hjalmarsson
- Department of Prosthodontics/Dental Materials Science, Institute of Odontology, Sahlgrenska Academy, University of Gothenburg, Göteborg, Sweden.,Specialist Dental Clinic, Folktandvården Sörmland AB, Mälar Hospital, Eskilstuna, Sweden.,Centre for Clinical Research Sörmland, Uppsala University, Eskilstuna, Sweden
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Svanborg P. A systematic review on the accuracy of zirconia crowns and fixed dental prostheses. Biomater Investig Dent 2020; 7:9-15. [PMID: 32010901 PMCID: PMC6968690 DOI: 10.1080/26415275.2019.1708202] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2019] [Accepted: 12/17/2019] [Indexed: 11/20/2022] Open
Abstract
Purpose The aim of this study was to review the fit and assess the accuracy of tooth-supported single and multi-unit zirconia fixed dental prostheses. Background The fit of zirconia restorations has been reported in several studies, but the accuracy of the manufacturing process is seldom discussed or used when drawing conclusions on the fit. Materials and methods A literature search of articles published in PubMed between 2 March 2013 and 1 February 2018 was performed using clearly defined inclusion and exclusion criteria. 841 articles were found and 767 were excluded after screening the title and abstract. After full-text analysis another 60 articles were excluded which left 14 articles to be included for data extraction. Fit was the mean of distances reported in the studies and accuracy was the fit minus the pre-set spacer Results For marginal gap of single crowns and multi-unit FDPs combined, the fit was 83 μm and the accuracy was 59 μm. The internal gap fit was 111 μm and the accuracy 61 μm. For the total gap, the fit was 101 μm, and the accuracy of the zirconia restorations was 53 μm. Conclusions Within the limitations of the present systematic review the fit of zirconia single crowns and multi-unit FDPs may be regarded as clinically acceptable, and the accuracy of the manufacturing of zirconia is ∼60 μm for marginal, internal, and total gap. Also, digital impressions seem to be associated with a smaller gap value.
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Affiliation(s)
- Per Svanborg
- Department of Prosthodontics/Dental Materials Science, Institute of Odontology, The Sahlgrenska Academy, University of Gothenburg, Göteborg, Sweden
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Kist S, Stawarczyk B, Kollmuss M, Hickel R, Huth KC. Fracture load and chewing simulation of zirconia and stainless‐steel crowns for primary molars. Eur J Oral Sci 2019; 127:369-375. [DOI: 10.1111/eos.12645] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/28/2019] [Indexed: 11/28/2022]
Affiliation(s)
- Stefan Kist
- Department of Conservative Dentistry and Periodontology University HospitalLMU Munich MunichGermany
| | - Bogna Stawarczyk
- Department of Prosthetic Dentistry University Hospital LMU Munich Munich Germany
| | - Maximilian Kollmuss
- Department of Conservative Dentistry and Periodontology University HospitalLMU Munich MunichGermany
| | - Reinhard Hickel
- Department of Conservative Dentistry and Periodontology University HospitalLMU Munich MunichGermany
| | - Karin C. Huth
- Department of Conservative Dentistry and Periodontology University HospitalLMU Munich MunichGermany
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Rohr N, Balmer M, Müller JA, Märtin S, Fischer J. Chewing simulation of zirconia implant supported restorations. J Prosthodont Res 2019; 63:361-367. [DOI: 10.1016/j.jpor.2019.02.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2018] [Revised: 02/01/2019] [Accepted: 02/13/2019] [Indexed: 11/28/2022]
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Lawson NC, Jurado CA, Huang CT, Morris GP, Burgess JO, Liu PR, Kinderknecht KE, Lin CP, Givan DA. Effect of Surface Treatment and Cement on Fracture Load of Traditional Zirconia (3Y), Translucent Zirconia (5Y), and Lithium Disilicate Crowns. J Prosthodont 2019; 28:659-665. [PMID: 31145492 DOI: 10.1111/jopr.13088] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/20/2019] [Indexed: 11/30/2022] Open
Abstract
PURPOSE To determine if surface treatment and cement selection for traditional 3 mol% yttria partially stabilized zirconia (3Y-PSZ), "translucent" 5 mol% yttria-stabilized zirconia (5Y-Z), or lithium disilicate crowns affected their fracture load. MATERIALS AND METHODS Crowns with 0.8 mm uniform thickness (96, n = 8/group) were milled of 3Y-PSZ (Lava Plus), 5Y-Z (Lava Esthetic), or lithium disilicate (e.max CAD) and sintered/crystallized. Half the crowns were either particle-abraded with 30 µm alumina (zirconias) or etched with 5% hydrofluoric acid (lithium disilicate), and the other half received no surface treatment. Half the crowns from each group were luted with resin-modified glass ionomer (RMGI, RelyX Luting Plus) and half were luted with a resin cement (RelyX Unicem 2) to resin composite dies. Crowns were load cycled (100,000 cycles, 100 N force, 24°C water) and then loaded with a steel indenter until failure. A three-way ANOVA examined the effects of material, cement, and surface treatment on fracture load. Post-hoc comparisons were performed with the Tukey-Krammer method. RESULTS Fracture load was signficiantly different for materials and cements (p < 0.0001) but not surface treatments (p = 0.77). All lithium disilicate crowns luted with RMGI failed in fatigue loading cycling; 3Y-PSZ and 5Y-Z crowns luted with resin showed a higher fracture load compared with RMGI (p < 0.001). With resin cement, there was no signficant difference in fracture load between 5Y-Z and lithium disiliciate (p = 1) whereas 3Y-PSZ had a higher fracture load (p < 0.0001). CONCLUSIONS Cement type affected fracture load of crowns but surface treatment did not. The 0.8 mm uniform thick crowns tested benefited from using resin cement regardless of type of ceramic material. Crowns fabricated from 5Y-Z may be particle-abraded if luted with resin cement.
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Affiliation(s)
- Nathaniel C Lawson
- Department of Clinical and Community Sciences, School of Dentistry, University of Alabama at Birmingham, Birmingham, AL
| | - Carlos A Jurado
- Department of Restorative Dentistry, Oregon Health & Science University, Portland, OR
| | - Chan-Te Huang
- Department of Clinical and Community Sciences, School of Dentistry, University of Alabama at Birmingham, Birmingham, AL.,Department of Dentistry, Chang Gung Memorial Hospital at Keelung, Taiwan
| | | | - John O Burgess
- Department of Clinical and Community Sciences, School of Dentistry, University of Alabama at Birmingham, Birmingham, AL
| | - Perng-Ru Liu
- Department of Restorative Sciences, School of Dentistry, University of Alabama at Birmingham, Birmingham, AL
| | - Keith E Kinderknecht
- Department of Restorative Sciences, School of Dentistry, University of Alabama at Birmingham, Birmingham, AL
| | - Chee Paul Lin
- Center for Clinical and Translational Science, Birmingham, AL
| | - Daniel A Givan
- Department of Restorative Sciences, School of Dentistry, University of Alabama at Birmingham, Birmingham, AL
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Lawson NC, Litaker MS, Ferracane JL, Gordan VV, Atlas AM, Rios T, Gilbert GH, McCracken MS. Choice of cement for single-unit crowns: Findings from The National Dental Practice-Based Research Network. J Am Dent Assoc 2019; 150:522-530. [PMID: 31030937 PMCID: PMC6538426 DOI: 10.1016/j.adaj.2019.01.021] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2018] [Revised: 12/26/2018] [Accepted: 01/02/2019] [Indexed: 11/28/2022]
Abstract
BACKGROUND In this article, the authors present clinical factors associated with the type of cement practitioners use for restoration of single-unit crowns. METHODS A total of 202 dentists in The National Dental Practice-Based Research Network recorded clinical details (including cement type) used for 3,468 single-unit crowns. The authors classified crowns as bonded if the dentist used a resin cement. The authors used mixed-model logistic regression to assess the associations between various clinical factors and the dentist's decision to bond. RESULTS A total of 38.1% of crowns were bonded, and 61.9% were nonbonded; 39.1% (79 of 202) of dentists never bonded a crown, and 20.3% (41 of 202) of dentists bonded every crown in the study. Crowns with excessive occlusal reduction (as judged by laboratory technicians) were more likely to be bonded (P = .02); however, there was no association with bonding and excessive taper (P = .15) or axial reduction (P = .08). Crowns were more likely to be bonded if they were fabricated from leucite-reinforced glass ceramic (76.5%) or lithium disilicate (70.8%) than if they were fabricated from layered zirconia (38.8%), full-contour zirconia (30.1%), full metal (14.7%), or porcelain-fused-to-metal (13.8%) (P < .01) restorative material. There was no significant association between choice to bond and crown margin location (P = .35). Crowns in the anterior maxilla were more likely to be bonded (P < .01). CONCLUSIONS Excessive occlusal tooth preparation, anterior location of a crown, and the use of glass ceramic crowns were associated significantly with the decision to bond. PRACTICAL IMPLICATIONS In this study, the authors identified factors significantly associated with the clinical decision made by practicing dentists when selecting a cement for restoration of single-unit crowns.
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Affiliation(s)
- Nathaniel C Lawson
- Department of Clinical and Community Sciences, School of Dentistry, University of Alabama at Birmingham, 1919 7 Ave S, Birmingham, AL, 35294, 205-975-8302,
| | - Mark S Litaker
- Department of Clinical and Community Sciences, School of Dentistry, University of Alabama at Birmingham, 1919 7 Ave S, Birmingham, AL, 35294, 205-934-1179,
| | - Jack L Ferracane
- Professor and Chair, Department of Restorative Dentistry, Oregon Health & Science University, 2730 S.W. Moody Avenue, Portland, OR 97201, 503-494-4327,
| | - Valeria V Gordan
- Professor, Department of Restorative Dental Sciences, College of Dentistry, University of Florida, 1395 Center Dr, Gainesville, FL 32610, 352-273-5846,
| | - Alan M Atlas
- Private practice, Department of Endodontics and Department of Preventive/Restorative Sciences, School of Dental Medicine, University of Pennsylvania, 240 S 40th St, Philadelphia, PA 19104, 215-545-3111,
| | - Tara Rios
- Private practice, 1205 E Alton Gloor Blvd, Brownsville, TX 78526, 956-542-1956,
| | - Gregg H Gilbert
- Department of Clinical and Community Sciences, School of Dentistry, University of Alabama at Birmingham, 1919 7 Ave S, Birmingham, AL, 35294, 205-934-5423,
| | - Michael S McCracken
- Department of Clinical and Community Sciences, School of Dentistry, University of Alabama at Birmingham, 1919 7 Ave S, Birmingham, AL, 205-934-1947,
| | - National Dental PBRN Collaborative Group
- The National Dental PBRN Collaborative Group includes practitioner, faculty, and staff investigators who contributed to this activity. A list is available at http://nationaldentalpbrn.org/collaborative-group.php
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Maroulakos G, Thompson GA, Kontogiorgos ED. Effect of cement type on the clinical performance and complications of zirconia and lithium disilicate tooth-supported crowns: A systematic review. Report of the Committee on Research in Fixed Prosthodontics of the American Academy of Fixed Prosthodontics. J Prosthet Dent 2019; 121:754-765. [DOI: 10.1016/j.prosdent.2018.10.011] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2018] [Revised: 10/17/2018] [Accepted: 10/22/2018] [Indexed: 12/28/2022]
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CAD-FEA modeling and analysis of different full crown monolithic restorations. Dent Mater 2018; 34:1342-1350. [DOI: 10.1016/j.dental.2018.06.024] [Citation(s) in RCA: 60] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2018] [Revised: 05/09/2018] [Accepted: 06/07/2018] [Indexed: 11/21/2022]
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Nakamura K, Ankyu S, Nilsson F, Kanno T, Niwano Y, Vult von Steyern P, Örtengren U. Critical considerations on load-to-failure test for monolithic zirconia molar crowns. J Mech Behav Biomed Mater 2018; 87:180-189. [PMID: 30077077 DOI: 10.1016/j.jmbbm.2018.07.034] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2018] [Revised: 07/19/2018] [Accepted: 07/24/2018] [Indexed: 11/30/2022]
Abstract
Application of monolithic zirconia crowns (MZCs) with reduced thickness to the molar region has been proposed, but potential complications have yet to be fully evaluated in laboratory tests. The present study aimed to develop a clinically relevant load-to-failure test in combination with fatigue treatments involving thermal and mechanical cycling (TC and MC) to evaluate the fracture resistance of molar MZCs. MZCs with a minimal thickness of 0.5 mm were bonded to dies made of resin-based composite (RBC), epoxy resin (EP), or polyoxymethylene-copolymer (POM-C). The samples were either untreated (UT) or subjected to TC (5-55 °C for 1 × 105 cycles) and MC (300 N for 2.4 × 106 cycles). The stress generated by TC and MC was simulated by finite element modeling. The load-to-failure test was performed using an inverse V-shaped two-plane indenter and was followed by fractographic analysis. The median values of fracture load for MZC/RBC and MZC/EP in the TC group were significantly lower than those in the UT group. MC also decreased the median value of fracture load for MZC/RBC significantly, but not that for MZC/EP and MZC/POM-C. Fractography revealed that the fracture started in the cervical area in all groups, which is similar to clinically failed crowns. The simulation confirmed stress concentration at the cervical area in both TC and MC groups. The present study suggests that the load-to-failure test using a two-plane indenter could induce clinically relevant fracture of MZCs, the vulnerability of the MZCs depends largely on the die material employed, and MZCs are more likely to be damaged by thermal fatigue than mechanical fatigue.
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Affiliation(s)
- Keisuke Nakamura
- Department of Advanced Free Radical Science, Tohoku University Graduate School of Dentistry, 4-1 Seiryo-machi, Aoba-ku, Sendai 980 8575, Japan.
| | - Shuhei Ankyu
- Sweden Dental Sendai (private practice), 1-6-2 Tsutsujigaoka, Miyagino-ku, Sendai 983 0852, Japan
| | - Fritjof Nilsson
- Division of Polymeric Materials, Department of Fibre and Polymer Technology, School of Engineering Sciences in Chemistry, Biotechnology and Health, KTH Royal Institute of Technology, SE-100 44 Stockholm, Sweden
| | - Taro Kanno
- Department of Advanced Free Radical Science, Tohoku University Graduate School of Dentistry, 4-1 Seiryo-machi, Aoba-ku, Sendai 980 8575, Japan
| | - Yoshimi Niwano
- Faculty of Nursing, Shumei University, 1-1 Daigaku-cho, Yachiyo, Chiba 276-0003, Japan
| | - Per Vult von Steyern
- Department of Materials Science and Technology, Faculty of Odontology, Malmö University, SE-205 06 Malmö, Sweden
| | - Ulf Örtengren
- Department of Cariology, Institute of Odontology, Sahlgrenska Academy, University of Gothenburg, SE-405 30 Gothenburg, Sweden; Department of Clinical Dentistry/Faculty of Health Sciences, The Arctic University of Norway, Tromsø 9037, Norway
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Weigl P, Sander A, Wu Y, Felber R, Lauer HC, Rosentritt M. In-vitro performance and fracture strength of thin monolithic zirconia crowns. J Adv Prosthodont 2018; 10:79-84. [PMID: 29713427 PMCID: PMC5917110 DOI: 10.4047/jap.2018.10.2.79] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2017] [Revised: 08/30/2017] [Accepted: 09/12/2017] [Indexed: 01/19/2023] Open
Abstract
PURPOSE All-ceramic restorations required extensive tooth preparation. The purpose of this in vitro study was to investigate a minimally invasive preparation and thickness of monolithic zirconia crowns, which would provide sufficient mechanical endurance and strength. MATERIALS AND METHODS Crowns with thickness of 0.2 mm (group 0.2, n=32) or of 0.5 mm (group 0.5, n=32) were milled from zirconia and fixed with resin-based adhesives (groups 0.2A, 0.5A) or zinc phosphate cements (groups 0.2C, 0.5C). Half of the samples in each subgroup (n=8) underwent thermal cycling and mechanical loading (TCML)(TC: 5℃ and 55℃, 2×3,000 cycles, 2 min/cycle; ML: 50 N, 1.2×106 cycles), while the other samples were stored in water (37℃/24 h). Survival rates were compared (Kaplan-Maier). The specimens surviving TCML were loaded to fracture and the maximal fracture force was determined (ANOVA; Bonferroni; α=.05). The fracture mode was analyzed. RESULTS In both 0.5 groups, all crowns survived TCML, and the comparison of fracture strength among crowns with and without TCML showed no significant difference (P=.628). Four crowns in group 0.2A and all of the crowns in group 0.2C failed during TCML. The fracture strength after 24 hours of the cemented 0.2 mm-thick crowns was significantly lower than that of adhesive bonded crowns. All cemented crowns provided fracture in the crown, while about 80% of the adhesively bonded crowns fractured through crown and die. CONCLUSION 0.5 mm thick monolithic crowns possessed sufficient strength to endure physiologic performance, regardless of the type of cementation. Fracture strength of the 0.2 mm cemented crowns was too low for clinical application.
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Affiliation(s)
- Paul Weigl
- Head of Department of Postgraduate Education, Carolinum Dental University Institute gGmbH, Department of Prosthetic Dentistry, Goethe-University Frankfurt am Main, Frankfurt, Germany
| | - Anna Sander
- Department of Prosthetic Dentistry, Faculty of Oral and Dental Medicine at JW Goethe-University Frankfurt am Main, Frankfurt, Germany
| | - Yanyun Wu
- Department of Postgraduate Education, Faculty of Oral and Dental Medicine at JW Goethe-University Frankfurt am Main, Frankfurt, Germany
| | - Roland Felber
- Department of Postgraduate Education, Carolinum Dental University Institute gGmbH, Department of Prosthetic Dentistry, Goethe-University Frankfurt am Main, Frankfurt, Germany
| | - Hans-Christoph Lauer
- Head of Department of Prosthetic Dentistry, Carolinum Dental University Institute gGmbH, Department of Prosthetic Dentistry, Goethe-University Frankfurt am Main, Frankfurt, Germany
| | - Martin Rosentritt
- Department of Prosthetic Dentistry, UKR University Hospital Regensburg, Regensburg, Germany
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Chang B, Goldstein R, Lin CP, Byreddy S, Lawson NC. Microleakage around zirconia crown margins after ultrasonic scaling with self-adhesive resin or resin modified glass ionomer cement. J ESTHET RESTOR DENT 2017; 30:73-80. [PMID: 29194924 DOI: 10.1111/jerd.12348] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
OBJECTIVES To measure microleakage around zirconia crown margins cemented with self-adhesive resin or resin modified glass ionomer (RMGI) cement after ultrasonic scaling. METHODS 16 molars were prepared for crowns (margin 0.5 mm coronal of cementum-enamel junction). Preparations were digitally scanned and zirconia crowns milled. Specimens were divided into two groups (n = 8): self-adhesive resin (RelyX Unicem 2) or resin modified glass ionomer (RMGI) (RelyX Luting Plus) cements. After cementation, specimens were ultrasonic scaled with a piezoelectric device (60 s, hand pressure). After thermocycling (20,000 cycles/5-55°C), specimens were immersed in 5 wt% fuchsine dye before sectioning bucco-lingually. Microleakage was examined under 40× light magnification. Statistical comparisons were made using a paired t test and a two-sample t test (α = .05). RESULTS Ultrasonic scaling did not alter microleakage at the margins of crowns (P = .31). There was no significant difference in microleakage of scaled and untreated margins with the use of different cements (P = .21). The amount of microleakage around margins that were scaled was not significantly different between cements (P = .14). Untreated margins of crowns cemented with RelyX Luting Plus showed a significantly higher microleakage than those cemented with RelyX Unicem 2 (P = .005). CONCLUSIONS Piezoelectric ultrasonic scaling did not increase microleakage at the margin of zirconia crowns cemented with self-adhesive resin or RMGI cements. CLINICAL SIGNIFICANCE Piezoelectric ultrasonic scaling around zirconia crowns did not impact marginal microleakage cemented with self-adhesive resin or RMGI cements.
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Affiliation(s)
- Bright Chang
- Division of Biomaterials, University of Alabama at Birmingham, Birmingham, Alabama
| | - Ronald Goldstein
- Department of Oral Rehabilitation, Augusta University Dental College of Georgia, Augusta, Georgia
| | - Chee Paul Lin
- Center for Clinical and Translational Science, University of Alabama at Birmingham, Birmingham, Alabama
| | | | - Nathaniel C Lawson
- Division of Biomaterials, University of Alabama at Birmingham, Birmingham, Alabama
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Rohr N, Märtin S, Fischer J. Correlations between fracture load of zirconia implant supported single crowns and mechanical properties of restorative material and cement. Dent Mater J 2017; 37:222-228. [PMID: 29176305 DOI: 10.4012/dmj.2017-111] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Zirconia implants that were restored with veneered zirconia displayed severe chipping rates of the restorations in clinical studies. Purpose of this study was to evaluate the fracture load of different zirconia implant supported monolithic crown materials (zirconia, alumina, lithium disilicate, feldspar ceramic and polymer-infiltrated ceramic) cemented with various cements (Harvard LuteCem SE, Harvard Implant Semi-permanent, Multilink Automix, VITA Adiva F-Cem). Flexural strength and fracture toughness of crown materials and compressive strength of the cements were measured. Fracture load values of crowns fabricated from lithium disilicate, feldspar ceramic and polymer-infiltrated ceramic were increased when cement with high compressive strength was used. Fracture loads for zirconia and alumina crowns were not influenced by the cement. Flexural strength and fracture toughness of the ceramics correlated linearly with the respective fracture load when using adhesive cement with high compressive strength. To achieve sufficient fracture load values, cementation with adhesive cement is essential for feldspar and polymer-infiltrated ceramic.
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Affiliation(s)
- Nadja Rohr
- Division of Dental Materials and Engineering, Department of Reconstructive Dentistry and Temporomandibular Disorders, University Center for Dental Medicine, University of Basel
| | | | - Jens Fischer
- Division of Dental Materials and Engineering, Department of Reconstructive Dentistry and Temporomandibular Disorders, University Center for Dental Medicine, University of Basel
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Zaugg LK, Meyer S, Rohr N, Zehnder I, Zitzmann NU. Fracture behavior, marginal gap width, and marginal quality of vented or pre-cemented CAD/CAM all-ceramic crowns luted on Y-TZP implants. Clin Oral Implants Res 2017; 29:175-184. [PMID: 29090511 DOI: 10.1111/clr.13075] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/05/2017] [Indexed: 11/28/2022]
Abstract
OBJECTIVES To investigate the fracture behavior and marginal gap region of CAD/CAM fabricated lithium disilicate (L) and zirconium dioxide (Z) crowns using palatal venting (PV), pre-cementation with custom analogs (CA), or conventional cementation technique (SP) with adhesive cement (A) or resin-modified glass ionomer cement (B). MATERIAL AND METHODS Twelve groups (n = 6) were set according to material (L, Z), cement (A, B), and technique (PV, CA, SP). Specimens were thermo-mechanical aged (TML), loaded until fracture (LF) and fracture patterns recorded. Marginal gap width and quality were assessed and compared to replicas obtained before and after TML. RESULTS Crown material significantly influenced LF with a mean of 1037.6 ± 282.4 N in L and 5356.3 ± 1207.0 N in Z groups (p < .001). Neither cement material nor cementation method affected the outcome. Fractures occurred along the mesial-distal central fissure in both materials. Gap width before TML was 22.04 ± 13.42 μm for L and 19.98 ± 12.72 μm for Z specimens, with overall no influence of crown material, cement type, or method. Marginal cleanliness just below the polished implant shoulder reached 66.7%-88.9% with A, and 91.7%-100% with B, and tended to increase in all groups during TML indicating a decrease in excess cement. Implant-crown junctions were cleaner with B compared to A (p ≤ .001) and along Z crown surfaces compared to L (p ≤ .007). CONCLUSIONS Crown venting of lithium disilicate and zirconium dioxide crowns did not affect the fracture load and patterns. Complete cement removal was rare, and the observed particle ablation requires further clinical attention, particularly with submucosal margins.
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Affiliation(s)
- Lucia K Zaugg
- Department of Periodontology, Endodontology and Cariology, University Center for Dental Medicine Basel, University of Basel, Basel, Switzerland.,Centre for Craniofacial and Regenerative Biology, Dental Institute, King's College London, London, UK
| | - Simon Meyer
- Department of Reconstructive Dentistry and Temporomandibular Disorders, Division of Dental Materials and Engineering, University Center for Dental Medicine Basel, University of Basel, Basel, Switzerland
| | - Nadja Rohr
- Department of Reconstructive Dentistry and Temporomandibular Disorders, Division of Dental Materials and Engineering, University Center for Dental Medicine Basel, University of Basel, Basel, Switzerland
| | - Isabella Zehnder
- Department of Periodontology, Endodontology and Cariology, University Center for Dental Medicine Basel, University of Basel, Basel, Switzerland
| | - Nicola U Zitzmann
- Department of Periodontology, Endodontology and Cariology, University Center for Dental Medicine Basel, University of Basel, Basel, Switzerland.,Department of Reconstructive Dentistry and Temporomandibular Disorders, Division of Dental Materials and Engineering, University Center for Dental Medicine Basel, University of Basel, Basel, Switzerland
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