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Vidal CMP, Teixeira EC, Armstrong SR, Qian F. Comparison of Adhesion Performance of a Self-curing and a Light-curing Universal Adhesive to Various Dental Substrates and CAD/CAM Materials. J Adhes Dent 2024; 26:31-40. [PMID: 38276890 DOI: 10.3290/j.jad.b4908469] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/27/2024]
Abstract
PURPOSE To compare the adhesion of a self-curing (Tokuyama Universal Bond, TUB) and a light-curing (Scotchbond Universal, SBU) universal adhesive to CAD/CAM materials, enamel, and dentin. This study also assessed differences in enamel adhesion between self-etch vs selective etching modes, as well as immediate and long-term adhesion to dentin for both adhesives. MATERIALS AND METHODS Shear bond strength (SBS) testing was used to assess adhesion to enamel, dentin, Lava Ultimate (LU), Vita Enamic (VE), IPS e.max CAD (LD), IPS e.max ZirCAD (3Y-Zir), and Lava Esthetic (5Y-Zir) (n = 10). Moreover, bonding to enamel in self-etch and selective etching modes (n = 10) as well as immediate and aged resin-dentin bond strength (24 h after bonding, after 100,000 thermal cycles [TC] and long-term storage) was evaluated using the microtensile bond-strength test (n = 30). Failure mode was also determined for the bonding to dentin. Statistical analyses consisted of one-way and two-way ANOVA with appropriate post-hoc Tukey-Kramer or two-sample t-tests, as well as the chi-squared or Fisher's exact test (α = 0.05). RESULTS TUB and SBU universal adhesives presented similar bonding to LU, VE, 3Y-Zir, and 5Y-Zir. However, SBS for TUB was superior to SBU when bonding to lithium-disilicate glass-ceramic (IPS e.max CAD). SBU showed better adhesion to dentin and enamel when used in the self-etch mode, while TUB promoted strong bond strength to enamel in the selective etching mode. TUB after TC was the only aging condition that yielded a significant reduction in resin-dentin bond strength. CONCLUSION In-vitro adhesion performance of the self-curing and light-curing universal adhesives varies depending on the dental substrate or CAD/CAM restorative material used for bonding.
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Unnadkat A, Kirby L, Kulanthaivel S, Rysavy O, Tsujimoto A, Song X, Teixeira EC. The Effect of Sintering on Zirconia Manufactured via Suspension-Enclosing Projection Stereolithography for Dental Applications: An In Vitro Study. Materials (Basel) 2023; 17:14. [PMID: 38203868 PMCID: PMC10779720 DOI: 10.3390/ma17010014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/30/2023] [Revised: 12/11/2023] [Accepted: 12/12/2023] [Indexed: 01/12/2024]
Abstract
BACKGROUND Zirconia is a widely used material in the dental industry due to its excellent mechanical and aesthetic properties. Recently, a new 3D printing process called suspension-enclosing projection stereolithography (SEPS) was introduced to fabricate zirconia dental restorations. However, the effect of the sintering time and temperature on the properties of zirconia produced via SEPS has not been fully investigated. METHODS Zirconia slurries were prepared with varying percentages of zirconia powders and 3D printing resins, and 5Y-TZP (5 mol% yttria-stabilized zirconia) (n = 40) and 3Y-TZP (3 mol% yttria-stabilized zirconia) (n = 40) bar specimens were fabricated via SEPS manufacturing. The specimens were sintered at different temperatures and dwell times, and their flexural strength, density, and phase composition were measured. The viscosity of the slurries was also measured. Statistical analysis was performed using Welch's ANOVA and Kruskal-Wallis tests to evaluate the impact of the sintering conditions. RESULTS Significant differences in flexural strength (p < 0.01) were observed between the 5Y-TZP samples, with those sintered at 1530 °C for 120 min showing an average strength of 268.34 ± 44.66 MPa, compared to 174.16 ± 42.29 MPa for those sintered at 1450 °C for 120 min. In terms of density, significant differences (p < 0.01) were noted for the 3Y-TZP specimens, with an average density of 6.66 ± 0.49 g/cm3 for samples sintered at 1530 °C for 120 min, versus 5.75 ± 0.55 g/cm3 for those sintered at 1530 °C for 10 min. X-ray diffraction confirmed the presence of a predominantly tetragonal phase in both materials. CONCLUSIONS Zirconia printed via SEPS manufacturing can be sintered at a higher temperature with shorter dwell times, thereby producing high density samples. Different sintering conditions can be used to fully sinter 3D-printed zirconia for potential dental applications.
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Affiliation(s)
- Amit Unnadkat
- Department of General Dentistry, College of Dentistry, University of Tennessee Health Science Center, Memphis, TN 38163, USA;
| | - Levi Kirby
- Department of Industrial and Systems Engineering, The University of Iowa College of Engineering, Iowa City, IA 52242, USA
| | - Senthilguru Kulanthaivel
- Department of Operative Dentistry, The University of Iowa College of Dentistry and Dental Clinics, Iowa City, IA 52242, USA; (S.K.); (A.T.)
| | - Oscar Rysavy
- Division of Biostatistics and Computational Biology, The University of Iowa College of Dentistry and Dental Clinics, Iowa City, IA 52242, USA
- Department of Biostatistics, The University of Iowa College of Public Health, Iowa City, IA 52242, USA
| | - Akimasa Tsujimoto
- Department of Operative Dentistry, The University of Iowa College of Dentistry and Dental Clinics, Iowa City, IA 52242, USA; (S.K.); (A.T.)
- Department of Operative Dentistry, Aichi Gakuin University School of Dentistry, Chikusa-ku, Nagoya 464-8651, Aichi, Japan
- Department of General Dentistry, Creighton University School of Dentistry, Omaha, NE 68102, USA
| | - Xuan Song
- Department of Industrial and Systems Engineering, The University of Iowa College of Engineering, Iowa City, IA 52242, USA
| | - Erica C. Teixeira
- Department of Operative Dentistry, The University of Iowa College of Dentistry and Dental Clinics, Iowa City, IA 52242, USA; (S.K.); (A.T.)
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Kulanthaivel S, Poppen J, Ribeiro Cunha S, Furman B, Whang K, Teixeira EC. Development of a Boron Nitride-Filled Dental Adhesive System. Polymers (Basel) 2023; 15:3512. [PMID: 37688138 PMCID: PMC10489713 DOI: 10.3390/polym15173512] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2023] [Revised: 08/17/2023] [Accepted: 08/18/2023] [Indexed: 09/10/2023] Open
Abstract
There is a dearth of adhesive systems capable of forming stable bonds between restorative materials and tooth surfaces. To address the concern, this study determined the effects of using methacrylate-functionalized boron nitride nanosheets (BNNSs) in a polymeric dental adhesive system. The bisphenol A glycidyl dimethacrylate (BisGMA):2 hydroxyethyl methacrylate (HEMA) (60:40) adhesive monomer blend with a photoinitiator was filled with 0 wt% (control), 0.1 wt%, and 1 wt% BNNSs and light cured. Fourier transform infrared spectroscopy was performed to determine the conversion degree of monomer double bonds (DoC). Water absorption and solubility were measured. Flexural strength and Youngs's modulus were evaluated to determine the mechanical properties of the composite adhesive system. Finally, dentin bond strength degradation and fracture mode were quantified with a microtensile bond test to confirm the bonding ability of the developed adhesive system. Results showed that the incorporation of BNNSs increased DoC (9.8% and 5.4% for 0.1 and 1 wt%, respectively), but it did not affect water sorption (101.9-119.72 (µg/mm3)), solubility (2.62-5.54 (µg/mm3)), Young's modulus (529.1-1716.1 MPa), or microtensile bond strength (46.66-54.72 MPa). Further studies are needed with varying BNNS loading percentages from 0.1 wt% to 1 wt% in order to more comprehensively determine the effect of BNNSs on dental adhesives.
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Affiliation(s)
- Senthilguru Kulanthaivel
- Department of Operative Dentistry, College of Dentistry & Dental Clinics, The University of Iowa, Iowa City, IA 52242, USA (J.P.)
| | - Jeremiah Poppen
- Department of Operative Dentistry, College of Dentistry & Dental Clinics, The University of Iowa, Iowa City, IA 52242, USA (J.P.)
| | - Sandra Ribeiro Cunha
- Department of Operative Dentistry, College of Dentistry & Dental Clinics, The University of Iowa, Iowa City, IA 52242, USA (J.P.)
| | | | - Kyumin Whang
- Department of Comprehensive Dentistry, The University of Texas Health Science Center at San Antonio, San Antonio, TX 78229, USA;
| | - Erica C. Teixeira
- Department of Operative Dentistry, College of Dentistry & Dental Clinics, The University of Iowa, Iowa City, IA 52242, USA (J.P.)
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Hopkins CE, Restrepo-Kennedy N, Elgreatly A, Comnick C, Vargas M, Teixeira EC. Fracture resistance of defective amalgam restorations repaired with a resin-based composite material. J Am Dent Assoc 2023; 154:141-150. [PMID: 36543651 DOI: 10.1016/j.adaj.2022.10.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2022] [Revised: 09/24/2022] [Accepted: 10/24/2022] [Indexed: 12/24/2022]
Abstract
BACKGROUND Repair is used to increase the longevity of defective restorations, such as large amalgams. The aim of this study was to investigate the fracture resistance and fracture modes of mesio-occlusodistal (MOD) amalgam molar restorations with extensive cuspal fracture repaired or replaced using a bulk-fill resin-based composite material. METHODS Amalgam restorations were placed in 84 permanent extracted molars and randomly assigned (n = 14) to groups: (1) MOD amalgam, (2) composite repair of 1-cusp fracture and adjacent proximal box, (3) composite repair of 1-cusp fracture, (4) composite repair of 2-cusp fracture, (5) replacement of 1-cusp defect and existing MOD amalgam, (6) replacement of 2-cusp defect and MOD amalgam. Each molar was prepared to simulate the assigned fracture and either repaired or replaced. Specimens were aged and then loaded to fracture. Fracture resistance and fracture modes were recorded. RESULTS The authors found significant differences (P < .001) between group 4 (1,652.3 N) and groups 5 (3,095.0 N), 1 (2,669.8 N), 6 (2,658.6 N), and 2 (2,442.9 N) as well as between group 3 (2,133.5 N) and group 5 (3,095.0 N). The results of the Fisher exact test showed differences among groups (P < .001), with group 5 having the highest number of nonrestorable fractures as well as higher fracture resistance on average. CONCLUSIONS Composite material is a viable option for the repair and replacement of cuspal defects, especially in the case of a 1-cusp fracture and 1-cusp fracture involving the adjacent proximal box. PRACTICAL IMPLICATIONS Within the limitations of this study, the repair of cusp fractures in existing MOD amalgam-restored molars is an appropriate treatment option, although replacement of the defect and existing restoration with resin-based composite will withstand higher forces.
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Tsujimoto A, Barkmeier WW, Teixeira EC, Takamizawa T, Miyazaki M, Latta MA. Fatigue bond strength of dental adhesive systems: Historical background of test methodology, clinical considerations and future perspectives. Japanese Dental Science Review 2022; 58:193-207. [PMID: 35789771 PMCID: PMC9250030 DOI: 10.1016/j.jdsr.2022.05.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2021] [Revised: 01/27/2022] [Accepted: 05/09/2022] [Indexed: 10/31/2022] Open
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Jurado CA, Barkmeier WW, Alshabib A, Alresayes SS, Fu CC, Teixeira EC, Baruth AG, Tsujimoto A. Effectiveness of Different Polishing Kits for Chairside CAD/CAM Provisional Restorative Materials. Oper Dent 2022; 47:670-677. [DOI: 10.2341/21-147-l] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/04/2021] [Indexed: 11/23/2022]
Abstract
SUMMARY
Objective: To investigate the efficacy of three specially designed polishing kits for provisional restorations made from three chairside computer-aided design and computer-aided manufacturing (CAD/CAM) provisional resin blocks.
Method: Ninety-six chairside CAD/CAM provisional restorations were milled out of three chairside CAD/CAM provisional resin blocks: (1) ArtBloc Temp (Merz Dental); (2) Telio CAD (Ivoclar Vivadent); and (3) Vita CAD-Temp (VITA Zahnfabrik). The provisional restorations for each material were allocated into the following groups: (1) milled restorations (no polish); (2) polished with CADMaster CAD/CAM Adjustment & Polishing Kit (CM, Shofu); (3) polished with KUT Ultimate Bisacryl (Temporaries) Polishing Kit (KU, Dental Savings Club); and (4) polished with K0330 PMMA Adjusting, Finishing & Polishing (KP, Brasseler USA). Optical profilometry and atomic force microscopy (AFM) were used to assess the surface roughness (Ra) of each provisional restoration at the microscale and nanoscale, respectively, and obtain topographical images. In addition, the milled and polished restorations were visually evaluated by 16 dentists.
Results: There was a strong positive correlation with Ra values between optical profilometry and AFM. Only KP significantly improved the surface roughness of CAD/CAM provisional restorations compared to the milled equivalent, regardless of material type or measurement modality (ie, lateral length scale). Although surface topography imaging with AFM revealed some shallow scratches, even for KP polished specimens, all KP polished restorations were categorized as clinically acceptable for provisional restorations in visual inspections from dentists.
Conclusion: Specially designed polishing kits for provisional restorations did not all improve the surface roughness of chairside CAD/CAM provisional restorations, regardless of the measurement method. KP was more consistently effective in polishing milled chairside CAD/CAM provisional restorations than CM and KU.
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Affiliation(s)
- CA Jurado
- Carlos A. Jurado, DDS, MS, Texas Tech University Health Science Center El Paso, Woody L. Hunt School of Dental Medicine, El Paso, TX, USA
| | - WW Barkmeier
- Wayne W. Barkmeier, DDS, MS, Department of General Dentistry, Creighton University School of Dentistry, Omaha, NE, USA
| | - A Alshabib
- Abdulrahman Alshabib, BDS, PhD, Department of Restorative Dentistry, King Saud University College of Dentistry, Riyadh, Saudi Arabia
| | - SS Alresayes
- Saad Saleh Alresayes, BDS, MS, Department of Restorative Dentistry, King Saud University College of Dentistry, Riyadh, Saudi Arabia
| | - C-C Fu
- Chin-Chuan Fu, DDS, MS, The University of Alabama at Birmingham School of Dentistry, Birmingham, AL, USA
| | - EC Teixeira
- Erica C Teixeira, DDS, MS, PhD, Department of Operative Dentistry, The University of Iowa College of Dentistry, Iowa City, IA, USA
| | - AG Baruth
- Andrew G. Baruth, PhD, Department of Physics, Creighton University College of Arts and Sciences, Omaha, NE, USA
| | - A Tsujimoto
- *Akimasa Tsujimoto, BDS, PhD, Department of Operative Dentistry, The University of Iowa College of Dentistry, Iowa City, IA, USA
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Kattan W, Urquhart O, Comnick C, McQuistan MR, Guzmán-Armstrong S, Kolker J, Teixeira EC. Repair versus replacement of defective direct restorations: A cross-sectional study among US dentists. J Am Dent Assoc 2021; 152:927-935. [PMID: 34489065 DOI: 10.1016/j.adaj.2021.05.017] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2020] [Revised: 05/06/2021] [Accepted: 05/24/2021] [Indexed: 12/22/2022]
Abstract
BACKGROUND Repair increases the longevity of restorations and is well-accepted by patients. In this study, the authors assessed the acceptance of dental restoration repair by dentists and determined the main variables of repair versus replacement of defective restorations. METHODS A 15-item questionnaire was developed and distributed electronically to the American Dental Association Clinical Evaluators panel members (n = 785) during a 2-week period in 2019. Descriptive, bivariate, and multivariable analyses were conducted. RESULTS Of the 387 respondents, 83.7% stated that they repair defective restorations, and 16% stated that they always replace them. Reasons to forego a restoration repair among dentists who perform repairs included defect size and carious lesion extension (42%) and negative personal experience or lack of success (37.9%). However, the latter was considerably higher for dentists who do not perform repairs (60.7%). The most commonly cited patient-related reason and tooth condition to repair restorations were limited patient finances (67%) and noncarious marginal defects (86%), respectively. Neither sex nor age group was significantly associated with the practice of restoration repair (P = .925 and P = .369, respectively). However, sole proprietors were more likely to perform repairs than those in an employee, associate, or contractor practice setting (P = .008). The most significant reason to forego restoration was negative experience or lack of success (P = .002). CONCLUSIONS Restoration repair is considered a treatment option for managing defective restorations. Negative personal experience or lack of success and practice setting influenced the dentists' decision to repair or replace a defective restoration. PRACTICAL IMPLICATIONS Understanding dentists' clinical challenges and practice environment is necessary when advocating for this approach.
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Takamiya H, Tsujimoto A, Teixeira EC, Jurado CA, Takamizawa T, Barkmeier WW, Latta MA, Miyazaki M, Garcia-Godoy F. Bonding and wear properties of self-adhesive flowable restorative materials. Eur J Oral Sci 2021; 129:e12799. [PMID: 34057777 DOI: 10.1111/eos.12799] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2020] [Revised: 03/10/2021] [Accepted: 04/16/2021] [Indexed: 11/29/2022]
Abstract
The purpose of this study was to evaluate the bonding and wear properties of self-adhesive flowable restorative materials. Five self-adhesive flowable restorative materials were used. The study parameters were: (i) shear bond strengths; (ii) microleakage; (iii) occlusal wear; and (iv) qualitative evaluation of the bonding interface. The range of shear bond strengths of the materials was as follows: 7.4-12.2 MPa to ground enamel, 22.5-32.5 MPa to etched enamel, and 1.3-4.2 MPa to dentin. The microleakage scores of the materials did not show any statistically significant differences regardless of the presence or absence of etching. The wear facets on the materials showed 0.099-0.447 mm3 of volume loss and 148.6-365.3 µm maximum depth, with statistically significant differences between materials. Scanning electron microscopic images of the interfaces of the materials showed good adaptation regardless of substrate. The bonding and wear properties of self-adhesive flowable restorative materials were still limited and showed lower values than previously reported results for nanofilled composites with an adhesive system. Selective enamel etching can improve the bonding performance of these materials.
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Affiliation(s)
- Hiroshi Takamiya
- Department of Operative Dentistry, Nihon University School of Dentistry, Tokyo, Japan
| | - Akimasa Tsujimoto
- Department of Operative Dentistry, University of Iowa, College of Dentistry, Iowa City, IA, USA
| | - Erica C Teixeira
- Department of Operative Dentistry, University of Iowa, College of Dentistry, Iowa City, IA, USA
| | - Carlos A Jurado
- Prosthodontics, Texas Tech University Health Sciences Center, El Paso, TX, USA
| | - Toshiki Takamizawa
- Department of Operative Dentistry, Nihon University School of Dentistry, Tokyo, Japan
| | - Wayne W Barkmeier
- Department of General Dentistry, Creighton University School of Dentistry, Omaha, NE, USA
| | - Mark A Latta
- Department of General Dentistry, Creighton University School of Dentistry, Omaha, NE, USA
| | - Masashi Miyazaki
- Department of Operative Dentistry, Nihon University School of Dentistry, Tokyo, Japan
| | - Franklin Garcia-Godoy
- Department of Bioscience Research, University of Tennessee Health Science Center, Memphis, TN, USA
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Jain A, Armstrong SR, Banas JA, Qian F, Maia RR, Teixeira EC. Dental adhesive microtensile bond strength following a biofilm-based in vitro aging model. J Appl Oral Sci 2020; 28:e20190737. [PMID: 32609185 PMCID: PMC7340208 DOI: 10.1590/1678-7757-2019-0737] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2019] [Accepted: 05/11/2020] [Indexed: 11/22/2022] Open
Abstract
OBJECTIVE Laboratory tests are routinely used to test bonding properties of dental adhesives. Various aging methods that simulate the oral environment are used to complement these tests for assessment of adhesive bond durability. However, most of these methods challenge hydrolytic and mechanical stability of the adhesive- enamel/dentin interface, and not the biostability of dental adhesives. To compare resin-dentin microtensile bond strength (μTBS) after a 15-day Streptococcus mutans (SM) or Streptococcus sobrinus (SS) bacterial exposure to the 6-month water storage (WS) ISO 11405 type 3 test. METHODOLOGY A total of 31 molars were flattened and their exposed dentin was restored with Optibond-FL adhesive system and Z-100 dental composite. Each restored molar was sectioned and trimmed into four dumbbell-shaped specimens, and randomly distributed based on the following aging conditions: A) 6 months of WS (n=31), B) 5.5 months of WS + 15 days of a SM-biofilm challenge (n=31), C) 15 days of a SM-biofilm challenge (n=31) and D) 15 days of a SS-biofilm challenge (n=31). μTBS were determined and the failure modes were classified using light microscopy. RESULTS Statistical analyses showed that each type of aging condition affected μTBS (p<0.0001). For Group A (49.7±15.5MPa), the mean μTBS was significantly greater than in Groups B (19.3±6.3MPa), C (19.9±5.9MPa) and D (23.6±7.9MPa). For Group D, the mean μTBS was also significantly greater than for Groups B and C, but no difference was observed between Groups B and C. CONCLUSION A Streptococcus mutans- or Streptococcus sobrinus-based biofilm challenge for 15 days resulted in a significantly lower μTBS than did the ISO 11405 recommended 6 months of water storage. This type of biofilm-based aging model seems to be a practical method for testing biostability of resin-dentin bonding.
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Affiliation(s)
- Aditi Jain
- University of Iowa, Department of Operative Dentistry, Iowa City, IA, USA
| | - Steve R Armstrong
- University of Iowa, Department of Operative Dentistry, Iowa City, IA, USA
| | - Jeffrey A Banas
- University of Iowa, Iowa Institute for Oral Health Research, Iowa City, IA, USA
| | - Fang Qian
- University of Iowa, Iowa Institute for Oral Health Research, Iowa City, IA, USA
| | - Rodrigo R Maia
- University of Iowa, Department of Operative Dentistry, Iowa City, IA, USA
| | - Erica C Teixeira
- University of Iowa, Department of Operative Dentistry, Iowa City, IA, USA
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Teixeira EC, Warren JJ, McKernan SC, McQuistan MR, Qian F. Prescribing practices for antibiotic prophylaxis in patients with prosthetic joints. Spec Care Dentist 2020; 40:198-205. [PMID: 31965592 DOI: 10.1111/scd.12450] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2019] [Revised: 01/01/2020] [Accepted: 01/04/2020] [Indexed: 01/22/2023]
Abstract
AIMS With the increasing number of patients with prosthetic joints, recommendations for antibiotic prophylaxis (AP) prior to dental procedures to prevent prosthetic joint infections (PJI) have changed. METHODS AND RESULTS This survey evaluated dentists' AP practices for patients with prosthetic joints undergoing dental procedures and their familiarity with the American Dental Association Guidelines (ADA CPG) and American Academy of Orthopaedic Surgeons Appropriate Use Criteria (AAOS AUC). Dentists' attitudes about antibiotic resistance, medical-legal aspects, and adverse effects to using AP were examined. Dentists (n = 574) were familiar (51.2%) with ADA CPG and with the AAOS AUC (25.8%). Familiarity varied according to years since graduation. Female dentists (63.5%) were more likely to be very familiar with the ADA CPG than male dentists (49.5%). Overall, 65.4% of respondents believed that AP is not effective in the prevention of PJI, and 19.4% believed there is enough evidence to support AP. For a healthy patient, 28.9% of dentists would never recommend AP, 44.9% would recommend AP within the first two years since prosthetic joint replacement. CONCLUSIONS Dentists' recommendations for the use of AP varied depending on different factors, including health status of the patient, dental procedure, time elapsed since joint surgery, suggesting that adherence to the ADA CPG and AUC is still challenging.
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Affiliation(s)
- Erica C Teixeira
- Department of Operative Dentistry, The University of Iowa College of Dentistry, Iowa City, Iowa
| | - John J Warren
- Department of Preventive and Community Dentistry, The University of Iowa College of Dentistry, Iowa City, Iowa
| | - Susan C McKernan
- Department of Preventive and Community Dentistry, The University of Iowa College of Dentistry, Iowa City, Iowa
| | - Michelle R McQuistan
- Department of Foundational Sciences, School of Dental Medicine at East Carolina University, Greenville, North Carolina
| | - Fang Qian
- Iowa Oral Health Institute, The University of Iowa College of Dentistry, Iowa City, Iowa
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Algamaiah H, Danso R, Banas J, Armstrong SR, Whang K, Rawls HR, Teixeira EC. The effect of aging methods on the fracture toughness and physical stability of an oxirane/acrylate, ormocer, and Bis-GMA-based resin composites. Clin Oral Investig 2019; 24:369-375. [PMID: 31104114 DOI: 10.1007/s00784-019-02912-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2018] [Accepted: 04/23/2019] [Indexed: 11/26/2022]
Abstract
PURPOSE To determine the effect of aging methods on the fracture toughness of a conventional Bis-GMA-based resin composite (Filtek Supreme), an ormocer-based resin composite (Admira), and an experimental hydrophobic oxirane/acrylate interpenetrating network resin system (OASys)-based composite. METHODS A 25 × 5 × 2.8-mm stainless-steel mold with 2.5 mm single-edge center notch, following ASTM standards [E399-90], was used to fabricate 135 specimens (n = 15) of the composite materials and randomly distributed into groups. For the baseline group, specimens were fabricated and then tested after 24-h storage in water. For the biofilm challenge, specimens were randomly placed in a six-well tissue culture plate and kept at 37 °C with bacterial growth media (Brain Heart Infusion (BHI); Streptococcus mutans) changed daily for 15 days. For the water storage challenge, specimens were kept in 5 ml of deionized distilled autoclaved water for 30 days at 37 °C. μCT evaluation by scanning the specimens was performed before and after the proposed challenge. Fracture toughness (KIc) testing was carried out following the challenges. RESULTS μCT surface area and volume analyses showed no significant changes regardless of the materials tested or the challenge. Filtek and Admira fracture toughness was significantly lower after the biofilm and water storage challenges. OASys mean fracture toughness values after water aging were significantly higher than that of baseline. Toughness values for OASys composites after biofilm aging were not statistically different when compared to either water or baseline values. CONCLUSION The fracture toughness of Bis-GMA and ormocer-based dental resin composites significantly decreased under water and bacterial biofilm assault. However, such degradation in fracture toughness was not visible in OASys-based composites. CLINICAL SIGNIFICANCE Current commercial dental composites are affected by the oral environment, which might contribute to the long-term performance of these materials.
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Affiliation(s)
- Hamad Algamaiah
- Department of Operative Dentistry, The Univeristy of Iowa, College of Dentistry & Dental Clinics, 801 Newton Rd, Iowa City, IA, 52242, USA
- Department of Restorative Dental Science, King Saud University College of Dentistry, Riyadh, 11545, Saudi Arabia
| | - Robert Danso
- Department of Comprehensive Dentistry, UT Health San Antonio, School of Dentistry, 7703 Floyd Curl Dr, San Antonio, TX, 78229, USA
| | - Jeffrey Banas
- Department of Operative Dentistry, The Univeristy of Iowa, College of Dentistry & Dental Clinics, 801 Newton Rd, Iowa City, IA, 52242, USA
| | - Steve R Armstrong
- Department of Operative Dentistry, The Univeristy of Iowa, College of Dentistry & Dental Clinics, 801 Newton Rd, Iowa City, IA, 52242, USA
| | - Kyumin Whang
- Department of Comprehensive Dentistry, UT Health San Antonio, School of Dentistry, 7703 Floyd Curl Dr, San Antonio, TX, 78229, USA
| | - H Ralph Rawls
- Department of Comprehensive Dentistry, UT Health San Antonio, School of Dentistry, 7703 Floyd Curl Dr, San Antonio, TX, 78229, USA
| | - Erica C Teixeira
- Department of Operative Dentistry, The Univeristy of Iowa, College of Dentistry & Dental Clinics, 801 Newton Rd, Iowa City, IA, 52242, USA.
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Grubbs TD, Vargas M, Kolker J, Teixeira EC. Efficacy of Direct Restorative Materials in Proximal Box Elevation on the Margin Quality and Fracture Resistance of Molars Restored With CAD/CAM Onlays. Oper Dent 2019; 45:52-61. [PMID: 31084532 DOI: 10.2341/18-098-l] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
PURPOSE The purpose of this study was to investigate the effect of four direct restorative materials that can be used in the proximal box elevation (PBE) technique. METHODS AND MATERIALS Seventy-five molar teeth were randomly assigned to one of five groups (n=15): type II glass ionomer (GI), type II resin-modified glass ionomer (RMGI), resin-based composite (RBC), bulk-fill (BF) resin-based composite, and a control with no box elevation procedure. Specimens were prepared for a standard mesio-occlusal-distal, computer-aided design/computer-aided manufactured (CAD-CAM) resin, nanoceramic onlay with mesial cervical margins located 1 mm above the cementoenamel junction (CEJ) and distal cervical margins located 2 mm below the CEJ. PBE was used to elevate the distal margins to 1 mm above the CEJ in all groups except the control group. For the control group the onlay margin was placed directly on the prepared distal tooth structure without PBE. A Lava Ultimate CAD/CAM resin, nanoceramic onlay restorative was manufactured and bonded on all specimens with RelyX Ultimate adhesive resin cement. The quality of the tooth-PBE material and PBE material-onlay interface was evaluated with scanning electron microscopy using epoxy resin replicas before and after cyclic loading (100,000 cycles, 1.2 Hz at 65N and 37°C). In addition to margin quality, the fracture resistance of each group was measured using a universal testing machine. Fracture pattern was recorded by visual examination. The Levene test for homogeneity and the Welch analysis of variance were completed for fracture resistance and margin quality. A χ2 test was completed for break mode. RESULTS For dentin margins, a statistically significant difference was detected between the RMGI and control groups at baseline (p=0.0442). All other groups-GI, RBC, and BF-showed no difference from the control at baseline (p>0.05). No statistical significance was observed among groups for post-cyclic fatigue (p=0.8735). For onlay margins, no statistical significance was observed among groups for pre-cyclic fatigue, post-cyclic fatigue, or change (p=0.9713, p=0.528, p=0.4385, respectively). No significant difference was observed for the fracture resistance among groups or for the type of break by material used (p=0.1593, p=0.77, respectively). CONCLUSION Within the parameters of this study, after mechanical fatigue, the materials used for PBE: RMGI, RBC, and BF, did not influence results in terms of margin quality and fracture resistance. Therefore, collective findings suggest that these materials might be suitable for PBE procedures. Nevertheless, clinical caution is recommended with any PBE procedure and further testing of GI materials is needed.
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13
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Pharr SW, Teixeira EC, Verrett R, Piascik JR. Influence of Veneering Fabrication Techniques and Gas-Phase Fluorination on Bond Strength between Zirconia and Veneering Ceramics. J Prosthodont 2016; 25:478-84. [PMID: 26849102 DOI: 10.1111/jopr.12451] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/02/2015] [Indexed: 11/30/2022] Open
Abstract
PURPOSE Porcelain chipping has been one of the main problems of porcelain-fused-to-zirconia restorations. This study evaluates the bond strengths of layered, pressed, and adhesively bonded porcelain to yttria-stabilized zirconia substrates that have undergone traditional preparation or gas-phase fluorination. MATERIALS AND METHODS A three-point bending test was used to evaluate the bond strength of the porcelain and zirconia interface. Sixty-six specimens were prepared (n = 11) following ISO 9693 and loaded until failure using an Instron testing machine. One-half of the zirconia substrates received gas phase fluorination treatment before veneering application. Three porcelain veneering methods were evaluated: layered, pressed, and adhesively bonded porcelain. Bond strength results were interpreted using a two-way ANOVA and a Bonferroni multiple comparisons test. Statistical significance was set at α = 0.05. RESULTS ANOVA revealed a statistically significant effect of the veneering fabrication methods. No main effect was observed regarding the surface treatment to the zirconia. There was a significant effect related to the veneering method used to apply porcelain to zirconia. For untreated zirconia, layered porcelain had a significantly higher flexural strength compared to pressed or bonded, while pressed and bonded porcelains were not significantly different from one another. For zirconia specimens receiving fluorination treatment, both layered and pressed porcelains had significantly higher bond strengths than adhesively bonded porcelain. In addition, fluorinated pressed porcelain was not statistically different from the control layered or fluorinated layered porcelain. CONCLUSION The choice of veneering fabrication technique was critical when evaluating the zirconia to porcelain interfacial bond strength. Bonded porcelain to zirconia had a lower flexural strength than layered or pressed porcelain, regardless of zirconia surface treatment. In addition, fluorination had an effect on the bond strength of pressed porcelain.
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Affiliation(s)
| | - Erica C Teixeira
- Department of Operative Dentistry, University of Iowa, Iowa City, IA
| | - Ronald Verrett
- Department of Comprehensive Dentistry, University of Texas Health Science Center, San Antonio, TX
| | - Jeffrey R Piascik
- RTI International, Center for Materials and Electronic Technologies, Durham, NC
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Curtis JG, Dossett J, Prihoda TJ, Teixeira EC. Effect of Bonding Agent Application Method on Titanium-Ceramic Bond Strength. J Prosthodont 2014; 24:394-400. [PMID: 25314910 DOI: 10.1111/jopr.12234] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/07/2014] [Indexed: 11/27/2022] Open
Abstract
PURPOSE Although milled titanium may be used as a substructure in fixed and implant prosthodontics, the application of the veneering porcelain presents particular challenges compared to traditional alloys. To address these challenges, some Ti ceramic systems incorporate the application of a bonding agent prior to the opaque layer. Vita Titankeramik's bonding agent is available as a powder, paste, and spray-on formulation. We examined the effect of these three application methods on the bond strength. MATERIALS AND METHODS Four titanium bars were milled from each of 11 wafers cut from grade II Ti using the Kavo Everest milling unit and a custom-designed milling toolpath. An experienced technician prepared the 25 × 3 × 0.5 mm(3) metal bars and applied bonding agent using one of three application methods, and then applied opaque, dentin, and enamel porcelains according to manufacturer's instructions to a 8 × 3 × 1 mm(3) porcelain. A control group received no bonding agent prior to porcelain application. The four groups (n = 11) were blindly tested for differences in bond strength using a universal testing machine in a three-point bend test configuration, based on ISO 9693-1:2012. RESULTS The average (SD) bond strengths for the control, powder, paste, and spray-on groups, respectively, were: 24.8 (2.6), 24.6 (2.6), 25.3 (4.0), and 24.1 (3.9) MPa. One-way ANOVA and Tukey's multiple comparison tests were performed between all groups. There were no statistically significant differences among groups (p = 0.951). CONCLUSION Titanium-porcelain bond strength was not affected by the use of a bonding agent or its application method when tested by ISO 9693-1 standard.
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Affiliation(s)
- Joseph G Curtis
- Department of Prosthodontics, 579th Dental Squadron, United States Air Force, Washington, DC
| | - Jon Dossett
- United States Air Force Dental Evaluation and Consultation Service, San Antonio, TX
| | - Thomas J Prihoda
- Department of Pathology, University of Texas Health Science Center at San Antonio, San Antonio, TX
| | - Erica C Teixeira
- Department of Operative Dentistry, The University of Iowa, College of Dentistry and Dental Clinics, Iowa City, IA
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15
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Harding AB, Norling BK, Teixeira EC. The Effect of Surface Treatment of the Interfacial Surface on Fatigue-Related Microtensile Bond Strength of Milled Zirconia to Veneering Porcelain. J Prosthodont 2012; 21:346-52. [DOI: 10.1111/j.1532-849x.2012.00843.x] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
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16
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Teixeira EC, Piascik JR, Stoner BR, Thompson JY. Zirconia–parylene multilayer thin films for enhanced fracture resistance of dental ceramics. Proc Inst Mech Eng H 2009; 223:897-902. [DOI: 10.1243/09544119jeim543] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Recent research has shown that the application of specific thin films can enhance the material properties of a laminate construct. In this study, the effect of different mono/multilayered films on the strength of a ceramic specimen is demonstrated. It is well established that cracks can initiate and/or propagate from the internal surfaces of all-ceramic dental restorations. Modifying that surface by thin-film deposition might help increase clinical longevity and applicability. Specimens were divided into the following groups according to different surface treatments received: uncoated (control group), 10 μm yttria-stabilized zirconia (YSZ) thin film, 10 μm parylene thin film, 9.75 μm YSZ + 0.25 μm parylene film, and a multilayered film (five layers of 1.25 μm YSZ + 0.75 μm parylene). Depositions were performed using a radio-frequency magnetron sputter system (working pressure 15 mT, 150 °C, 30:1 Ar/O2 gas ratio) to produce the YSZ layers, and a vapour deposition process was used to produce the parylene layers. Flexural strength measurements were carried out by three-point bending (span = 10 mm) in a servo-electric material testing system in deioinized (DI) water (37 °C). The results showed that the strength of the specimen significantly increased with the deposition of all types of coating, showing the greatest increase with the multilayered film (∼32 per cent). It is hypothesized that a multilayer thin film (brittle/ductile) can promote crack deflection, causing strength enhancement of the brittle construct.
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Affiliation(s)
- E C Teixeira
- Department of General Dentistry, University of Texas Health Science Center at San Antonio, San Antonio, Texas, USA
| | | | | | - J Y Thompson
- Department of Prosthodontics, NOVA Southeastern University, Fort Lauderdale, Florida, USA
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17
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Teixeira EC, Piascik JR, Stoner BR, Thompson JY. Dynamic fatigue behavior of dental porcelain modified by surface deposition of a YSZ thin film. J Prosthodont 2008; 17:527-31. [PMID: 18761578 DOI: 10.1111/j.1532-849x.2008.00340.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
PURPOSE The objective of this study was to evaluate the basic fatigue parameters of a dental porcelain modified by deposition of a yttria-stabilized zirconia (YSZ) thin film and to compare the data to that of an unmodified control. METHODS Two hundred bars (2 x 2 x 15 mm(3)) were cut from ProCAD blocks. Specimens were wet-polished with 1200-grit SiC abrasive. One surface of each bar was sandblasted with 50 microm Al2O3 abrasive (50 psi). Half the specimens were further modified through deposition of a 3-microm YSZ thin film on the sandblasted surface. Depositions were performed using an radio frequency magnetron sputter system (working pressure of 15 mT, 150 degrees C, 30:1 Ar:O2 gas ratio). Specimens were tested at different stressing rates: 5.0, 0.1, and 0.01 MPa/s (n = 25/group) in deionized water (37 degrees C), and inert strength was determined in air (25 degrees C, 70 MPa/s). All strength measurements were carried out by three-point bending (span = 10 mm) in a servo-electric test system. RESULTS The mean flexural strength values (MPa) and standard deviation for the uncoated sandblasted group were: 98.6 (5.5), 90.7 (5.9), and 84.2 (8.5), and for the sandblasted + YSZ thin film group: 125 (9.4), 119.3 (7.8), and 102.8 (7.0), for the highest to the lowest stressing rates, respectively. The fatigue parameters n and lnB were calculated by linear regression of dynamic fatigue data. For the uncoated group, n = 38 and lnB = 4.7 MPa(2)/s, and for the coated group, n = 33 and lnB = 10.8 MPa(2)/s. Weibull analysis was also performed showing that the characteristic parameter (sigma(o)) was 113.3 and 125.7 MPa for the uncoated and coated group, respectively. CONCLUSIONS There was an increase in strength for specimens modified by application of a YSZ thin film. It is hypothesized that thin-film application modifies flaws or residual surface stress states.
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Affiliation(s)
- Erica C Teixeira
- Curriculum in Applied and Materials Sciences, University of North Carolina, Chapel Hill, NC, USA
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18
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Teixeira EC, Piascik JR, Stoner BR, Thompson JY. Dynamic fatigue and strength characterization of three ceramic materials. J Mater Sci Mater Med 2007; 18:1219-24. [PMID: 17277977 DOI: 10.1007/s10856-007-0131-4] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/24/2005] [Accepted: 03/03/2006] [Indexed: 05/13/2023]
Abstract
Fracture strength and fatigue parameters of three ceramic materials submitted to dynamic fatigue were evaluated. A machinable leucite-reinforced dental ceramic, aluminum oxide, and yttria-stabilized zirconia (YSZ) were tested. The inert strength of the materials was determined in air (25 degrees C) at stressing rates of 70, 250, 400 MPa/s for Porcelain, Alumina and YSZ respectively. The data was analyzed using a two-parameter Weibull distribution. The Weibull modulus (m) and the characteristic of fracture (sigma0) parameters were determined for each material. Specimens were also tested in 3-point bending at different stressing rates in distilled/deionized water at 37 degrees C (dynamic fatigue) in order to calculate the fatigue parameters n and ln B. The strength for each material was characterized using Strength-Probability-Time (SPT) diagrams for 1 day, 1 year and 10 years. YSZ showed a high-fracture strength sigma0 (1,459 MPa) at a failure probability of 63.2% and high resistance to subcritical crack growth. YSZ and alumina showed better resistance to slow crack growth than porcelain, indicating less susceptibility to strength degradation by stress corrosion. Lifetime predictions after 10 years indicate a reduction of 50%, 36% and 29% in strength for porcelain, alumina and YSZ respectively. YSZ seems to be a very promising material for long-term dental and biomedical applications.
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Affiliation(s)
- Erica C Teixeira
- Department of Diagnostic Sciences and General Dentistry, University of North Carolina, Chapel Hill, NC 27599, USA.
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Teixeira EC, Piascik JR, Stoner BR, Thompson JY. Effect of YSZ thin film coating thickness on the strength of a ceramic substrate. J Biomed Mater Res B Appl Biomater 2007; 83:459-63. [PMID: 17471523 DOI: 10.1002/jbm.b.30855] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Although ceramics are used for many different biomedical applications they are brittle materials that can be compromised by surface defects when under stress. The objective of this study was to evaluate the effect of surface modification with an yttria-stabilized zirconia (YSZ) thin film coating on the strength of a machinable dental ceramic. Fifty bars (2 mm x 2 mm x 15 mm) were cut from ProCAD (Ivoclar-Vivadent) blocks. Specimens were wet-polished through 1200-grit SiC abrasive. One surface of each bar was sandblasted with 50 microm Al(2)O(3) abrasive (0.34 MPa). Specimens were further modified through the deposition of a sputtered YSZ thin film on the sandblasted surface. Different thin film thicknesses were evaluated: 1, 3, 5, and 7 microm. Depositions were performed using a radio frequency magnetron sputter system (working pressure of 15 mT, 150 degrees C, 30:1 Ar/O(2) gas ratio). Flexural strength measurements were carried out by three-point bending (span = 10 mm) in a servo-electric material testing system in DI water (37 degrees C). The results showed that the strength of porcelain significantly increased with the deposition of a 3-microm YSZ thick coating. A nonlinear relationship was observed between film thickness and strength. Strengthening of porcelain is shown through the application of a sputtered YSZ thin film. It is presumed that the strengthening mechanism is due to modification of surface flaws and/or surface residual stress by the applied thin film.
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Affiliation(s)
- Erica C Teixeira
- School of Dentistry-UNC Chapel Hill, Diagnostic Sciences & General Dentistry, 115 Dental Office Building, CB No. 7450, Chapel Hill, North Carolina 27599-7450, USA.
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20
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Teixeira EC, Bayne SC, Thompson JY, Ritter AV, Swift EJ. Shear bond strength of self-etching bonding systems in combination with various composites used for repairing aged composites. J Adhes Dent 2005; 7:159-64. [PMID: 16052765] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
PURPOSE Repair of worn, broken or discolored composite restorations can be accomplished using new composite material and dentin bonding systems. The purpose of this study was to investigate the effectiveness of self-etching adhesive systems for composite re-bonding procedures onto different composite substrates that had been aged for 6 years prior to testing. MATERIALS AND METHODS Two hundred cylinders (4 mm x 5 mm) of composite were fabricated using 4 hybrid composites [AeliteFil (Bisco), Prodigy (SDS Kerr), TPH (Dentsply Caulk), and Z100 (3M ESPE)] following manufacturers' directions and stored for 6 years in 1% NaCl solution. After aging, each specimen was wet polished through 600-grit SiC and randomly assigned to a self-etching bonding system (Adper Prompt L-Pop/Z100 [3M ESPE]; Tyrian One-Step Plus/AeliteFil [Bisco]; OptiBond Solo Plus SE/Prodigy [SDS Kerr], Xeno III/TPH [Dentsply Caulk]) or a total-etch control (Prime&Bond NT/TPH [Dentsply Caulk]) (n = 10 per group). Shear bond strengths (SBS) for repairs were evaluated after 48 h (crosshead speed = 0.5 mm/min) and were compared by two-way ANOVA (p = 0.05) with Tukey post-hoc tests. RESULTS Significant differences (p < or = 0.05) were detected for the main effects (substrates and bonding systems), but the interaction was not significant. SBS for bonding systems were from highest to lowest: (1) Prime&Bond NT, (2) OptiBond Solo Plus SE, (3) Adper Prompt L-Pop, (4) Xeno III, (5) Tyrian One-Step Plus. SBS of the repair systems to Z100 were significantly lower than those to the other composite substrates. CONCLUSION Self-etching systems can be used to repair aged composite, but the efficacy of repair of aged composite is system dependent.
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Affiliation(s)
- Erica C Teixeira
- Department of Operative Dentistry, School of Dentistry, CB#7450, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599-7450, USA.
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Braga CF, Alves RCM, Teixeira EC, Pire M. Aerosols concentration in the Candiota area applying different gravimetric methods of sampling and numeric modelling. J Environ Monit 2002; 4:897-902. [PMID: 12509042 DOI: 10.1039/b204816g] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The main purpose of the present work is to study the concentration of atmospheric particles in the Candiota region, in the state of Rio Grande do Sul, where the Presidente Médici coal power plant is located. Aerosol samples were collected at the studied locations between December 2000 and December 2001 during 24 h periods at 15 day intervals using HV PM10 and dichotomous samplers. Then, the values obtained with the ISCST (Industrial Source Complex Term) model, with the HV PM10 sampler at all studied stations, and with the dichotomous sampler at the 8 de Agosto station were compared with each other. The results show that the values for the model had been underestimated in relation to the HV PM10 data for the studied stations, but agreed with the values obtained with the dichotomous sampler.
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Affiliation(s)
- C F Braga
- Fundaçdo Estadual de Proteção Ambiental, Rua Carlos Chagas 551707, Porto Alegre-RS 90030-020, Brazil
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da Silva ACR, Ferro JA, Reinach FC, Farah CS, Furlan LR, Quaggio RB, Monteiro-Vitorello CB, Van Sluys MA, Almeida NF, Alves LMC, do Amaral AM, Bertolini MC, Camargo LEA, Camarotte G, Cannavan F, Cardozo J, Chambergo F, Ciapina LP, Cicarelli RMB, Coutinho LL, Cursino-Santos JR, El-Dorry H, Faria JB, Ferreira AJS, Ferreira RCC, Ferro MIT, Formighieri EF, Franco MC, Greggio CC, Gruber A, Katsuyama AM, Kishi LT, Leite RP, Lemos EGM, Lemos MVF, Locali EC, Machado MA, Madeira AMBN, Martinez-Rossi NM, Martins EC, Meidanis J, Menck CFM, Miyaki CY, Moon DH, Moreira LM, Novo MTM, Okura VK, Oliveira MC, Oliveira VR, Pereira HA, Rossi A, Sena JAD, Silva C, de Souza RF, Spinola LAF, Takita MA, Tamura RE, Teixeira EC, Tezza RID, Trindade dos Santos M, Truffi D, Tsai SM, White FF, Setubal JC, Kitajima JP. Comparison of the genomes of two Xanthomonas pathogens with differing host specificities. Nature 2002; 417:459-63. [PMID: 12024217 DOI: 10.1038/417459a] [Citation(s) in RCA: 782] [Impact Index Per Article: 35.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The genus Xanthomonas is a diverse and economically important group of bacterial phytopathogens, belonging to the gamma-subdivision of the Proteobacteria. Xanthomonas axonopodis pv. citri (Xac) causes citrus canker, which affects most commercial citrus cultivars, resulting in significant losses worldwide. Symptoms include canker lesions, leading to abscission of fruit and leaves and general tree decline. Xanthomonas campestris pv. campestris (Xcc) causes black rot, which affects crucifers such as Brassica and Arabidopsis. Symptoms include marginal leaf chlorosis and darkening of vascular tissue, accompanied by extensive wilting and necrosis. Xanthomonas campestris pv. campestris is grown commercially to produce the exopolysaccharide xanthan gum, which is used as a viscosifying and stabilizing agent in many industries. Here we report and compare the complete genome sequences of Xac and Xcc. Their distinct disease phenotypes and host ranges belie a high degree of similarity at the genomic level. More than 80% of genes are shared, and gene order is conserved along most of their respective chromosomes. We identified several groups of strain-specific genes, and on the basis of these groups we propose mechanisms that may explain the differing host specificities and pathogenic processes.
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Affiliation(s)
- A C R da Silva
- Departamento de Bioquímica, Instituto de Química, Av. Prof. Lineu Prestes 748, São Paulo, SP, Brazil
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