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Limones A, Celemín-Viñuela A, Romeo-Rubio M, Castillo-Oyagüe R, Gómez-Polo M, Martínez Vázquez de Parga JA. Outcome measurements and quality of randomized controlled clinical trials of tooth-supported fixed dental prostheses: A systematic review and qualitative analysis. J Prosthet Dent 2024; 132:326-336. [PMID: 36109260 DOI: 10.1016/j.prosdent.2022.04.022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2021] [Revised: 04/25/2022] [Accepted: 04/26/2022] [Indexed: 11/16/2022]
Abstract
STATEMENT OF PROBLEM The lack of consensus regarding a standardized set of outcome measurements and noncompliance with current reporting guidelines in clinical trials of tooth-supported fixed dental prostheses (FDPs) hamper interstudy comparability, compromise scientific evidence, and waste research effort and resources in prosthetic dentistry. PURPOSE The primary objective of this systematic review was to identify all primary and secondary outcome measurements assessed in randomized controlled trials (RCTs) of tooth-supported FDPs. Secondary objectives were to assess their methodological quality by using the Cochrane Collaboration's risk of bias tool (RoB, v2.0) and their reporting quality by means of a standardized 16-item CONSORT assessment tool through published reports. MATERIAL AND METHODS An electronic search was conducted in MEDLINE, EMBASE, and Cochrane library to identify all RCT-related articles published in the past 10 years. Differences in RoB were tested with the Pearson chi-squared test, and those in CONSORT score with the Student t test. RESULTS A total of 64 RCTs from 79 publications were deemed eligible. The diversity of outcome measures used in the field is apparent. Twenty percent of the included studies had a low RoB, 79% showed some concerns, and 1% had a high RoB. The mean ±standard deviation CONSORT compliance score was 22.56 ±3.17. Trials adhered to the CONSORT statement reported lower RoB than those that did not adhere (P<.001). RCTs with a low RoB reported more comprehensive adherence to CONSORT guidelines than those with some concerns (MD 4 [95% CI 1.52-6.48]; P=.004). CONCLUSIONS A standardized core outcome reporting set in clinical research on tooth-supported FDPs remains evident. Adherence to the CONSORT statement continues to be low, with some RoB concerns that can be improved.
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Affiliation(s)
- Alvaro Limones
- Student, Assistant Professor, Department of Conservative & Prosthetic Dentistry, Faculty of Dentistry, Complutense University of Madrid (UCM), Madrid, Spain.
| | - Alicia Celemín-Viñuela
- Professor, Department of Conservative & Prosthetic Dentistry, Faculty of Dentistry, Complutense University of Madrid (UCM), Madrid, Spain
| | - Marta Romeo-Rubio
- Professor, Department of Conservative & Prosthetic Dentistry, Faculty of Dentistry, Complutense University of Madrid (UCM), Madrid, Spain
| | - Raquel Castillo-Oyagüe
- Cathedratic Professor, Department of Conservative & Prosthetic Dentistry, Faculty of Dentistry, Complutense University of Madrid (UCM), Madrid, Spain
| | - Miguel Gómez-Polo
- Professor, Department of Conservative & Prosthetic Dentistry, Faculty of Dentistry, Complutense University of Madrid (UCM), Madrid, Spain
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Shihabi S, Chrcanovic BR. Clinical outcomes of tooth-supported monolithic zirconia vs. porcelain-veneered zirconia fixed dental prosthesis, with an additional focus on the cement type: a systematic review and meta-analysis. Clin Oral Investig 2023; 27:5755-5769. [PMID: 37626273 PMCID: PMC10560185 DOI: 10.1007/s00784-023-05219-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2023] [Accepted: 08/15/2023] [Indexed: 08/27/2023]
Abstract
PURPOSE To compare the failure rates and the prevalence of technical complications between full-coverage tooth-supported monolithic zirconia (MZ) and porcelain-veneered zirconia (PVZ) fixed dental prosthesis, based on a systematic literature review. METHODS An electronic search was performed in three databases, supplemented by hand searching. Several statistical methods were used. RESULTS Seventy-four publications reported 6370 restorations (4264 PVZ; 2106 MZ; 8200 abutment teeth; 3549 patients), followed up until 152 months. A total of 216 prostheses failed, and survival was statistically significant different between groups. PVZ had higher occurrence of complications than MZ; the difference was especially greater for either minor or major chipping. The difference in prevalence of either minor or major chipping was statistically significant for PVZ prostheses between cementation with glass ionomer and adhesive resin cement (higher), adhesive resin and resin-modified glass ionomer cement (RMGIC, higher), and between RMGIC (higher) and glass ionomer cement. For MZ the difference was significant only for minor chipping between RMGIC (higher) and adhesive resin cement. Abutment teeth to PVZ prostheses more often lost vitality. Decementation was not observed with RMGIC. Air abrasion did not seem to clinically decrease the decementation risk. The 5-year difference in the occurrence of minor or major chipping between MZ and PVZ prostheses was statistically significant, but nor for catastrophic fracture. CONCLUSION Tooth-supported PVZ prostheses present higher failure and complication rates than MZ prosthesis. The difference in complications is striking when it comes to chipping. CLINICAL RELEVANCE Awareness of the outcome differences between different types of zirconia prostheses is important for clinical practice.
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Affiliation(s)
| | - Bruno Ramos Chrcanovic
- Department of Prosthodontics, Faculty of Odontology, Malmö University, Carl Gustafs Väg 34, 214 21 Malmö, Sweden
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Reslan MR, Sayed M, Rayyan MM, Farouk H. Effect of Cement Type on Fracture Resistance and Mode of Failure of Monolith vs Bilayered Zirconia Single Crowns. J Contemp Dent Pract 2023; 24:576-581. [PMID: 38193181 DOI: 10.5005/jp-journals-10024-3546] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2024]
Abstract
AIM To compare the fracture resistance and the mode of failure between monolith second-generation zirconia and bilayered first-generation zirconia single crowns cemented by resin cement and glass ionomer cement (GIC). MATERIALS AND METHODS A total of 36 maxillary first premolar crowns (5 mm in length × 4 mm in cervical diameter, with a base of 6 mm) were computer-aided design-computer-aided manufacturing (CAD-CAM) milled. They were divided into the following two groups (n = 18) according to the fabrication techniques: Group M - monolith zirconia crown (1-mm axial thickness and 2-mm occlusal thickness) and group B - bilayer zirconia crown (0.5-mm axial thickness and 1-mm occlusal thickness). Each group was further subdivided into the following two subgroups (n = 9) according to the cement used: Subgroup G - cemented using GIC; subgroup R - cemented using resin cement. All crowns were cemented to their corresponding resin dies and stored in distilled water for 72 hours. Each specimen was mounted to the lower member of the universal testing machine with a load cell of 5 kN and a crosshead speed of 0.5 mm/minute. Failure modes were analyzed for fractured parts using scanning electron microscopy (SEM). RESULTS Subgroup MR recorded the highest fracture resistance mean value (3616 ± 347.2 N) while the BG subgroup recorded the statistically significant lowest fracture resistance mean value (1728.7 ± 115.3 N). One-way analysis of variance (ANOVA) followed by pairwise Tukey's post hoc tests revealed a statistically significant difference (p = 0.0001) between groups M and B. One-way ANOVA followed by pairwise Tukey's post hoc tests also showed a statistically significant difference (p = 0.0297) between the types of cement used (subgroups G and R). CONCLUSION Monolith zirconia crowns had better mean fracture resistance than bilayered zirconia crowns. Resin cement improved the fracture resistance compared to GIC. Monolith zirconia crowns showed bulk fracture while bilayered zirconia crowns showed chipping fracture. CLINICAL SIGNIFICANCE Monolith zirconia crowns present a good prosthetic alternative overcoming the veneer chipping drawback of bilayered zirconia crowns. In addition, resin cement could increase the fracture resistance of zirconia crowns.
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Affiliation(s)
- Maria Rafaat Reslan
- Department of Oral Rehabilitation Sciences, Faculty of Dentistry, Beirut Arab University, Beirut, Lebanon
| | - Mohamed Sayed
- Department of Fixed Prosthodontics, Faculty of Dentistry, Sinai University, Kantara Campus, Sinai, Egypt, Phone: +20 1288670943, e-mail:
| | - Mohammad Mostafa Rayyan
- Department of Fixed Prosthodontics, Faculty of Dentistry, Sinai University, Kantara Campus, Sinai, Egypt
| | - Hadeel Farouk
- Department of Conservative Dentistry, Faculty of Dentistry, Sinai University, Kantara Campus, Sinai, Egypt
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Aswal GS, Rawat R, Dwivedi D, Prabhakar N, Kumar V. Clinical Outcomes of CAD/CAM (Lithium disilicate and Zirconia) Based and Conventional Full Crowns and Fixed Partial Dentures: A Systematic Review and Meta-Analysis. Cureus 2023; 15:e37888. [PMID: 37213959 PMCID: PMC10199723 DOI: 10.7759/cureus.37888] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/14/2023] [Indexed: 05/23/2023] Open
Abstract
Although CAD/CAM (computer-aided design/computer-aided manufacturing) restorations act as a favorable alternative to conventional metal-ceramic restorations for fixed dental prostheses, little is known about their intermediate and persistent clinical performance. This systematic review and meta-analysis aimed to assess the clinical performance in terms of biological, technical, and esthetic aspects and the survival and success ratios for single full crowns (SFCs) and fixed partial dentures (FPDs) fabricated by CAD/CAM and conventional techniques and according to the materials used (zirconia {ZC} and lithium disilicate {LD}). The population, intervention, control, outcome, and study design (PICOS) strategy was used to electronically search key terms in the PubMed, Cochrane Library, Embase, and Wiley Online databases for randomized control trials (RCTs) and cohort studies. The bias risks for RCTs and cohort studies were assessed using the Cochrane collaboration tool and the Newcastle-Ottawa Scale (NOS). Meta-analysis was performed using Rev5 from Cochrane. A total of 13 studies reporting on 1598 restorations in 1161 patients with a mean observation period of 3.6 years (minimum-maximum: 1-9.3 years) met the inclusion criteria. Meta-analysis of the included studies indicated that CAD/CAM manufacturing resulted in 1.17, 1.14, and 16.88 (95% CI: 0.64-2.17, 0.86-1.52, 7.59-37.56) higher biological, technical, and esthetic complications than conventional manufacturing of restorations. However, the difference was significant for esthetic complications only (p<0.00001). A significant difference was observed for all biological, technical, and aesthetic aspects between SFCs and FPDs (odds ratio {OR} = 2.61 vs. 1.78, 95% CI: 1.92-3.56 vs. 1.33-2.38; p<0.00001). The survival ratio of SFCs was 2.69 (95% CI: 1.98-3.65), significantly higher compared to the 1.76 (95% CI: 1.31-2.36) of FPDs (p<0.00001). The success ratio of FPDs at 1.18 (95% CI: 0.83-1.69) was significantly lower compared to SFCs at 2.36 (95% CI: 1.68-3.33). The clinical performance of LD with 2.42 (CI: 1.16-5.03) was significantly higher compared to ZC with 2.22 (CI: 1.78-2.77) (p<0.00001). The biological, technical, and aesthetic behaviors showed similar clinical outcomes between the CAD/CAM and conventional groups. LD could be a good alternative to zirconia, but its intermediate or persistent clinical performance needs to be evaluated. Overall, zirconia and CAD/CAM techniques must evolve further to outclass the conventional techniques used in the fabrication of SFCs and FPDs.
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Affiliation(s)
- Gunjan S Aswal
- Dentistry, The University of the West Indies, St. Augustine, TTO
| | - Renu Rawat
- Dentistry, The University of the West Indies, St. Augustine, TTO
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Mechanical Properties of Translucent Zirconia: An In Vitro Study. PROSTHESIS 2023. [DOI: 10.3390/prosthesis5010004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Background: The introduction of translucent zirconia has improved mimetics: nevertheless, a reduction in the mechanical performance was registered. The study aim was to investigate the mechanical characteristics of a high-translucent zirconia used for monolithic restorations before and after the aging process compared to a low-translucent zirconia. Methods: A total of 23 specimens were used in the present study. Group A (n = 10) was made of a high-translucent Y-TZP; group B (n = 7) was made of a low-translucent Y-TZP and finally group C (n = 6) was an aged high-translucent Y-TZP. Flexural strength, fracture toughness, brittleness, microcrack’s propagation and grain size were analyzed. Results: The Vickers hardness was: 1483 ± 187 MPa (group C); 1102 ± 392 MPa (group A); 1284 ± 32 MPa (group B). The flexural strength was: 440 (±96.2) MPa (group C); 427 (±59.5) MPa (group A); 805 (±198.4) MPa (group B). The fracture toughness was: 5.1 (±0.7) MPa.m1/2 (group C); 4.9 (±0.9) MPa.m1/2 (group A); 8.9 (±1.1) MPa.m1/2 (group B). The brittleness was: 295 (±42.8) (group C), 230.9 (±46.4) (group A) and 144.9 (±20.3) (group B). The grain size was: 2.75 (±1.2) µm2 (group A); 0.16 (±0.05) µm2 (group B); 3.04 (±1.1) µm2 (group C). Conclusions: The significant reduction in the mechanical properties of high-translucent zirconia, compared to the traditional one, suggests their use in the anterior/lateral area (up to premolars).
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Rathmann F, Pohl M, Rammelsberg P, Bömicke W. Up to 10 years clinical performance of zirconia ceramic and metal-ceramic fixed partial dentures: A retrospective study. J Prosthet Dent 2022:S0022-3913(22)00692-8. [PMID: 36464507 DOI: 10.1016/j.prosdent.2022.11.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2022] [Revised: 11/03/2022] [Accepted: 11/03/2022] [Indexed: 12/02/2022]
Abstract
STATEMENT OF PROBLEM Completely veneered zirconia ceramic (ZC) fixed partial dentures (FPDs) have been reported to have a higher incidence of ceramic chipping than the standard metal-ceramic FPDs. However, data from comparative long-term studies are sparse. PURPOSE The purpose of this retrospective study was to compare the long-term survival, chipping-free survival, and success of ceramic-veneered high noble metal alloy (HN), base metal alloy (cobalt-chromium alloy) (CC), and ZC FPDs and to isolate risk factors for the incidence of failure, veneer chipping, and overall complications. MATERIAL AND METHODS Data from 289 study participants (58.7% women; mean age, 57.97 ±11.51 years) provided with a total of 400 FPDs comprising 197 (49.3%) HN FPDs, 121 (30.3%) CC FPDs, and 82 (20.5%) ZC FPDs fabricated from presintered 3 mol% yttria-stabilized zirconia (mean time of service, 6.85 ±3.25 years) were evaluated. Of these, 278 (69.5%) FPDs were provided by dentists and 122 (30.5%) by dental students. Five- and 10-year survival, chipping-free survival, and success rates were calculated using the Kaplan-Meier method and compared with the log-rank test. Risk factors were assessed using Cox regression analysis. The study was exploratory, so all P values were considered exploratory and descriptive. RESULTS The 5- and 10-year survival rates were 94.7% and 77.8% for HN, 93.7% and 81.2% for CC, and 92.9% and 53.3% for ZC FPDs, respectively, indicating no clear difference in survival among the framework materials. The 5- and 10-year chipping-free rates were 94.1% and 82.8% for HN, 96.1% and 78.9% for CC, and 82.6% and 62.2% for ZC FPDs, respectively, indicating a difference between HN and ZC, and CC and ZC restorations. The 5- and 10-year success rates were 83.7% and 55.3% for HN, 86.5% and 51.4% for CC, and 68.9% and 30.2% for ZC FPDs, respectively, indicating a difference between HN and ZC, and CC and ZC restorations. The Cox regression model indicated framework material as an influencing risk factor for success, and this influence persisted when chipping was investigated. Compared with zirconia, the use of a metal alloy reduced the risk of chipping or the occurrence of complications by up to one-third. CONCLUSIONS All FPDs showed high 5-year survival rates and acceptable 10-year survival rates with no strong differences among the materials. Higher success and chipping-free rates were observed for both HN and CC restorations compared with ZC restorations. Metal frameworks had a lower risk for complications or veneer chipping than zirconia frameworks.
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Affiliation(s)
- Friederike Rathmann
- Assistant Professor, Department of Prosthodontics, University Hospital Heidelberg, University of Heidelberg, Heidelberg, Germany
| | - Moritz Pohl
- Assistant Professor, Institute of Medical Biometry, University of Heidelberg, Heidelberg, Germany
| | - Peter Rammelsberg
- Director, Department of Prosthodontics, University Hospital Heidelberg, University of Heidelberg, Heidelberg, Germany
| | - Wolfgang Bömicke
- Associate Professor, Department of Prosthodontics, University Hospital Heidelberg, University of Heidelberg, Heidelberg, Germany.
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Do tooth-supported zirconia restorations present more technical failures related to fracture or loss of retention? Systematic review and meta-analysis. Clin Oral Investig 2022; 26:5129-5142. [PMID: 35660957 DOI: 10.1007/s00784-022-04573-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2022] [Accepted: 05/29/2022] [Indexed: 11/03/2022]
Abstract
OBJECTIVES This systematic review was performed to determine the main cause of technical failure of tooth-supported zirconia crowns and fixed partial dentures (FPDs), categorizing them as fracture/chipping or loss of retention/decementation. MATERIALS AND METHODS Electronic and manual searches were performed for randomized clinical trials, prospective clinical trials, and prospective cohort studies that reported the technical failure rates of zirconia restorations. The Cochrane Collaboration risk-of-bias tool and Newcastle-Ottawa scale were used to assess the quality of the studies. RESULTS Fifty-two studies were included and most of them had unclear risk of bias. Considering all reported fractures/chipping, for veneered crowns with 1 to 3 years of follow-up, the relative risk (RR) of fracture in relation to loss or retention was 3.95 (95% CI 1.18-13.23; p = 0.03). For 4 to 6 years of follow-up, the RR was 5.44 (95% CI 1.41-20.92; p = 0.01). For veneered FPDs with 1 to 3 years of follow-up, the RR was 5.98 (95% CI 2.31-15.01; p = 0.0002). For 4 to 6 years of follow-up, the RR was 3.70 (95% CI 1.63-8.41; p = 0.002). For 7 years or more of follow-up, the RR was 3.45 (95% CI 1.84-6.46; p = 0.0001). When only framework fractures were considered, there were no significant differences for the RR in all follow-up periods (p > 0.05). CONCLUSIONS Higher RR for fracture/chipping in relation to decementation for veneered zirconia crowns and FPDs at all follow-up times. For framework fractures, no difference was observed between the risk of failure of the restoration due to fracture or decementation. CLINICAL RELEVANCE Zirconia crowns and FPDs showed relatively high success and survival rates. However, considering the technical failures, there is approximately four times higher chance of fracture/chipping than loss of retention for both single and multi-unit tooth-supported veneered zirconia restorations.
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Prott LS, Spitznagel FA, Bonfante EA, Malassa MA, Gierthmuehlen PC. Monolithic zirconia crowns: effect of thickness reduction on fatigue behavior and failure load. J Adv Prosthodont 2021; 13:269-280. [PMID: 34777717 PMCID: PMC8558575 DOI: 10.4047/jap.2021.13.5.269] [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] [Received: 05/26/2021] [Revised: 08/30/2021] [Accepted: 09/14/2021] [Indexed: 11/23/2022] Open
Abstract
PURPOSE The objective of this study was to evaluate the effect of thickness reduction and fatigue on the failure load of monolithic zirconia crowns. MATERIALS AND METHODS 140 CAD-CAM fabricated crowns (3Y-TZP, inCorisTZI, Dentsply-Sirona) with different ceramic thicknesses (2.0, 1.5, 1.0, 0.8, 0.5 mm, respectively, named G2, G1.5, G1, G0.8, and G0.5) were investigated. Dies of a mandibular first molar were made of composite resin. The zirconia crowns were luted with a resin composite cement (RelyX Unicem 2 Automix, 3M ESPE). Half of the specimens (n = 14 per group) were mouth-motion-fatigued (1.2 million cycles, 1.6 Hz, 200 N/ 5 – 55℃, groups named G2-F, G1.5-F, G1-F, G0.8-F, and G0.5-F). Single-load to failure was performed using a universal testing-machine. Fracture modes were analyzed. Data were statistically analyzed using a Weibull 2-parameter distribution (90% CI) to determine the characteristic strength and Weibull modulus differences among the groups. RESULTS Three crowns (21%) of G0.8 and five crowns (36%) of G0.5 showed cracks after fatigue. Characteristic strength was the highest for G2, followed by G1.5. Intermediate values were observed for G1 and G1-F, followed by significantly lower values for G0.8, G0.8-F, and G0.5, and the lowest for G0.5-F. Weibull modulus was the lowest for G0.8, intermediate for G0.8-F and G0.5, and significantly higher for the remaining groups. Fatigue only affected G0.5-F. CONCLUSION Reduced crown thickness lead to reduced characteristic strength, even under failure loads that exceed physiological chewing forces. Fatigue significantly reduced the failure load of 0.5 mm monolithic 3Y-TZP crowns.
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Affiliation(s)
- Lea Sophia Prott
- Department of Prosthodontics, Medical Faculty and University Hospital Düsseldorf, Heinrich-Heine-University, Düsseldorf, Germany
| | - Frank Akito Spitznagel
- Department of Prosthodontics, Medical Faculty and University Hospital Düsseldorf, Heinrich-Heine-University, Düsseldorf, Germany
| | - Estevam Augusto Bonfante
- Department of Prosthodontics and Periodontology, Bauru School of Dentistry, University of Sao Paulo, Bauru, SP, Brazil
| | | | - Petra Christine Gierthmuehlen
- Department of Prosthodontics, Medical Faculty and University Hospital Düsseldorf, Heinrich-Heine-University, Düsseldorf, Germany
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Nakamura K, Tarkeshi A, Niklasson A, Shishido S, Svanborg P, Barkarmo S, Örtengren U. Influence of crystalline phase transformation induced by airborne-particle abrasion and low-temperature degradation on mechanical properties of dental zirconia ceramics stabilized with over 5 mol% yttria. J Mech Behav Biomed Mater 2021; 125:104890. [PMID: 34673358 DOI: 10.1016/j.jmbbm.2021.104890] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2021] [Revised: 10/05/2021] [Accepted: 10/10/2021] [Indexed: 11/30/2022]
Abstract
Monolithic dental prostheses fabricated from 5 mol% yttria-stabilized zirconia (5YZ) have been developed to improve the translucency of conventional 3 mol% yttria-stabilized zirconia. In this study, we aimed to evaluate the influence of airborne-particle abrasion (APA) and low-temperature degradation (LTD) on the mechanical properties of 5YZ in association with the crystalline phase transformation. In total, 120 disc-shaped specimens of two brands of 5YZ (Lava Esthetic and Katana UTML) were prepared. The specimens were divided into four groups (n = 15 for each group): (i) control, (ii) APA, (iii) LTD, and (iv) APA + LTD groups. APA was performed with 50 μm alumina particles, and LTD was induced by autoclaving at 134 °C for 50 h. The biaxial flexural strength of the specimens was assessed using a piston-on-three-ball test according to ISO 6872:2015, and Vickers hardness was determined using a microhardness tester. The crystalline phase was analyzed by the Rietveld refinement of X-ray diffraction patterns. APA significantly increased the flexural strength of the Lava Esthetic specimens, whereas LTD hardly affected the strength of both materials. APA and APA + LTD significantly increased the Vickers hardness of both materials. According to Rietveld analysis, the pseudocubic phase was predominant in both materials, i.e., 66 mass% and 81 mass% in the Lava Esthetic and Katana UTML specimens, respectively. APA induced the rhombohedral phase at approximately 37 mass% in both materials, while LTD induced the monoclinic phase at 2.8 mass% in the Lava Esthetic specimens and 0.9 mass% in the Katana UTML specimens. APA + LTD weakly affected the amount of the rhombohedral phase but slightly increased the amount of the monoclinic phase. These findings suggest that APA may improve the mechanical properties of 5YZ, particularly hardness, via the generation of the rhombohedral phase. In contrast, the influence of LTD on the mechanical and microstructural properties of 5YZ was limited.
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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.
| | - Aria Tarkeshi
- Department of Cariology, Institute of Odontology, Sahlgrenska Academy, University of Gothenburg, SE-405 30, Gothenburg, Sweden
| | - Alexander Niklasson
- Department of Cariology, Institute of Odontology, Sahlgrenska Academy, University of Gothenburg, SE-405 30, Gothenburg, Sweden
| | - Shunichi Shishido
- Department of Advanced Free Radical Science, Tohoku University Graduate School of Dentistry, 4-1 Seiryo-machi, Aoba-ku, Sendai, 980 8575, Japan
| | - Per Svanborg
- Department of Prosthetic Dentistry/Dental Materials Science, Institute of Odontology, Sahlgrenska Academy, University of Gothenburg, SE-405 30, Gothenburg, Sweden
| | - Sargon Barkarmo
- Department of Prosthetic Dentistry/Dental Materials Science, Institute of Odontology, Sahlgrenska Academy, University of Gothenburg, SE-405 30, Gothenburg, Sweden
| | - Ulf Örtengren
- Department of Cariology, Institute of Odontology, Sahlgrenska Academy, University of Gothenburg, SE-405 30, Gothenburg, Sweden
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Zandinejad A, Das O, Barmak AB, Kuttolamadom M, Revilla-León M. The Flexural Strength and Flexural Modulus of Stereolithography Additively Manufactured Zirconia with Different Porosities. J Prosthodont 2021; 31:434-440. [PMID: 34580962 DOI: 10.1111/jopr.13430] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2021] [Revised: 09/01/2021] [Accepted: 09/09/2021] [Indexed: 11/28/2022] Open
Abstract
PURPOSE Additive manufacturing (AM) technologies are capable of fabricating complex geometries with different porosities. However, the effect of such porosities on mechanical properties of stereolithography (SLA) AM zirconia with different porosities is unclear. The purpose of this in vitro study was to investigate the mechanical properties namely flexural strength, and flexural modulus of AM zirconia with different porosities. MATERIALS AND METHODS A bar (25 × 4 × 3 mm) for flexural strength test (ISO standard 6872/2015) was designed by CAD software program and standard tessellation language (STL) file was obtained. The STL file was used to fabricate a total of 80 bars in four groups. Three experimental groups each containing 20 samples were manufactured using an SLA ceramic printer (CeraMaker 900; 3DCeram Co) and zirconia material (3DMix ZrO2 paste; 3DCeram Co) with different sintering post processing to achieve different porosities including 0%-porosity (AMZ0), 20%-porosity (AMZ20), and 40%-porosity (AMZ40). The same STL file was used for subtractive manufacturing or milling of 20 zirconia bars as control group (CNCZ) with the same dimensions using a commercial zirconia. Three-point bending tests were performed for all groups following ISO standard 6872/2015 specification using a universal testing machine. Outcomes measured included load at fracture, mean flexural strength, and flexural modulus and they were compared across the experimental groups using a one-way ANOVA. Post hoc pair wise comparison between each pair of the groups were performed using Tukey test. RESULTS There was a significant difference between the four groups, in terms of fracture load, flexural strength and flexural modulus using one-way ANOVA. AM zirconia with 0% porosity (AMZ0) showed the highest value for fracture load (1132.7 ± 220.6 N), flexural strength (755.1 ± 147.1 MPa) and flexural modulus (41,273 ± 2193 MPa) and AM zirconia with 40% porosity (AMZ40) showed the lowest fracture load (72.13 ± 13.42 N), flexural strength (48.09 ± 8.95 MPa) and flexural modulus (7177 ± 506 MPa). Tukey's pairwise comparisons detected a significant difference between all the possible pairs for all variables except flexural modulus between AMZ0 and CNCZ. The Weibull moduli presented the lowest value for AMZ20 (4.4) followed by AMZ40 (6.1), AMZ0 (6.1), and the highest value was for CNCZ (8.1). CONCLUSION AM zirconia with 0% porosity showed significantly higher flexural strength and flexural modulus when compared to milled and AM zirconia with 20% and 40% porosities.
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Affiliation(s)
| | - Omprakash Das
- College of Engineering, Texas A&M University, College Station, TX
| | | | | | - Marta Revilla-León
- College of Dentistry, Texas A&M University, Dallas, TX.,School of Dentistry, University of Washington, Seattle, WA.,Revilla Research Center, Madrid, Spain
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Zarone F, Di Mauro MI, Spagnuolo G, Gherlone E, Sorrentino R. Fourteen-year evaluation of posterior zirconia-based three-unit fixed dental prostheses. J Dent 2020; 101:103419. [DOI: 10.1016/j.jdent.2020.103419] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2020] [Revised: 06/03/2020] [Accepted: 06/25/2020] [Indexed: 10/24/2022] Open
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12
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Sawada T, Schille C, Schweizer E, Geis-Gerstorfer J, Takemoto S. Bond strength of commercial veneering porcelain to experimental cast Ti-Cr alloy. Dent Mater J 2020; 39:825-833. [PMID: 32418951 DOI: 10.4012/dmj.2019-245] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
This study evaluated bond strengths of three commercial veneering porcelains to experimental cast titanium-chromium (Ti-Cr) alloy and commercially pure titanium (cp-Ti) via three-point bending test. After the bending test, the fractured specimens were analyzed using an electron probe microanalyzer (EPMA). The Ti-Cr specimens showed lower bond strengths than the cp-Ti specimens, irrespective of the layering porcelain material; however, all the strengths exceeded the minimum requirement of ISO 9693-1:2012 (>25 MPa). EPMA revealed that titanium and/or chromium elements were detected on the debonded porcelain surface of the Ti-Cr and cp-Ti specimens in the case of the higher bond strength. Contrastingly, the residual porcelain was retained on the metallic surface in the case of the lower bond strength. Although porcelain bonding to the titanium alloy is influenced by porcelain type, the Ti-Cr alloy could be feasible for porcelain-fused-to-metal restorations.
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Affiliation(s)
- Tomofumi Sawada
- Department of Biomedical Engineering, School of Dentistry, Iwate Medical University.,Section Medical Materials Science and Technology, University Hospital Tübingen
| | - Christine Schille
- Section Medical Materials Science and Technology, University Hospital Tübingen
| | - Ernst Schweizer
- Section Medical Materials Science and Technology, University Hospital Tübingen
| | | | - Shinji Takemoto
- Department of Biomedical Engineering, School of Dentistry, Iwate Medical University
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AL‐Turki L, Merdad Y, Abuhaimed TA, Sabbahi D, Almarshadi M, Aldabbagh R. Repair bond strength of dental computer‐aided design/computer‐aided manufactured ceramics after different surface treatments. J ESTHET RESTOR DENT 2020; 32:726-733. [DOI: 10.1111/jerd.12635] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2020] [Revised: 06/22/2020] [Accepted: 07/18/2020] [Indexed: 11/29/2022]
Affiliation(s)
- Lulwa AL‐Turki
- Department of Oral and Maxillofacial Prosthodontics, Faculty of Dentistry King Abdulaziz University Jeddah Saudi Arabia
| | - Yasser Merdad
- Department of Operative Dentistry, Faculty of Dentistry King Abdulaziz University Jeddah Saudi Arabia
| | - Tariq A. Abuhaimed
- Department of Operative Dentistry, Faculty of Dentistry King Abdulaziz University Jeddah Saudi Arabia
| | - Dania Sabbahi
- Department of Dental Public Health, Faculty of Dentistry King Abdulaziz University Jeddah Saudi Arabia
| | | | - Raghad Aldabbagh
- Department of Oral and Maxillofacial Prosthodontics, Faculty of Dentistry King Abdulaziz University Jeddah Saudi Arabia
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Wear analysis and topographical properties of monolithic zirconia and CoCr against human enamel after polishing and glazing procedures. J Mech Behav Biomed Mater 2020; 105:103712. [DOI: 10.1016/j.jmbbm.2020.103712] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2019] [Revised: 02/18/2020] [Accepted: 02/19/2020] [Indexed: 11/17/2022]
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Brandeburski SBN, Vidal ML, Collares K, Zhang Y, Della Bona A. Edge chipping test in dentistry: A comprehensive review. Dent Mater 2020; 36:e74-e84. [PMID: 32001022 PMCID: PMC7042093 DOI: 10.1016/j.dental.2020.01.019] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2019] [Revised: 12/01/2019] [Accepted: 01/14/2020] [Indexed: 11/30/2022]
Abstract
OBJECTIVE Literature on edge chipping test applied to dental materials and structures has been systematically reviewed with regard to the evaluation methods and parameters used. DATA A systematic search of the literature retrieved 3484 relevant studies. After removing duplicates, 1848 records were screened by titles and abstracts and 1797 were excluded; 51 papers were assessed full text for eligibility. Twenty papers were included in this study and they were organized according to the dental materials and structures tested as follows: 2 studies on human tooth, 9 on dental ceramics, 5 on polymer-based composites, and 4 studies evaluated both ceramic and polymer-based materials. SOURCES MEDLINE/PubMed, Scopus and Web of Science databases were searched up to June 2019 without restriction on date and language. STUDY SELECTION In vitro studies using edge chipping test on dental materials and structures were included. CONCLUSIONS Different methods have been used for edge chipping test, regardless of reported parameters. There is significant evidence that edge chipping test is a relevant approach to predict chipping behavior of dental materials and tooth tissues because chips produced from most edge chipping studies are similar to clinically reported chipping failures.
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Affiliation(s)
| | - Marina Lermenn Vidal
- Postgraduate Program in Dentistry, Dental School, University of Passo Fundo, Brazil
| | - Kaue Collares
- Postgraduate Program in Dentistry, Dental School, University of Passo Fundo, Brazil
| | - Yu Zhang
- Department of Biomaterials and Biomimetics, New York University College of Dentistry, New York, USA
| | - Alvaro Della Bona
- Postgraduate Program in Dentistry, Dental School, University of Passo Fundo, Brazil.
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Zimmermann M, Ender A, Mehl A. Influence of CAD/CAM Fabrication and Sintering Procedures on the Fracture Load of Full-Contour Monolithic Zirconia Crowns as a Function of Material Thickness. Oper Dent 2019; 45:219-226. [PMID: 31738694 DOI: 10.2341/19-086-l] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
OBJECTIVE The purpose of this in vitro study was to analyze the effect of computer-aided design/computer-aided manufacturing (CAD/CAM) fabrication and sintering procedures on the fracture load of monolithic zirconia crowns with different material thicknesses adhesively seated to methacrylate dies fabricated with stereolithography technology. METHOD Monolithic zirconia crowns were fabricated from inCoris TZI C material with a chairside CAD/CAM system (CEREC MCXL) comprising three material thicknesses (0.5/1.0/1.5 mm, n=8 each). Two CAD/CAM fabrication procedures (milling, MI; grinding, GR), two chairside sintering procedures (superspeed, SS; speedfire sintering, SF), and one labside sintering procedure (classic, CL) were evaluated. In total, 144 crowns were fabricated. Restorations were adhesively seated to methacrylate dies fabricated with SLA technology. Thermomechanical cycling (TCML) was performed before fracture testing. Loading forces until fracture were registered and statistically analyzed with one-way analysis of variance (ANOVA), post hoc Scheffé test, and three-way ANOVA (α=0.05). RESULTS Test groups showed statistically significant differences (p<0.05). The highest mean value was found for 1.5-mm crowns of group GR_SF with 3678.6 ± 363.9 N. The lowest mean value was found for group 0.5-mm crowns of group MI_SF with 382.4 ± 30.7 N. There was a significant three-way interaction effect between thickness, sintering, and processing [F(4,126)=9.542; p<0.001; three-way ANOVA, significance level α=0.05]. CONCLUSIONS CAD/CAM fabrication and sintering procedures influence the maximum loading force of monolithic zirconia crowns with different material thicknesses. A material thickness of 0.5 mm should be considered as a critical thickness for monolithic zirconia crown restorations.
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Nagarkar SR, Perdigão J, Seong WJ, Theis-Mahon N. Digital versus conventional impressions for full-coverage restorations: A systematic review and meta-analysis. J Am Dent Assoc 2019; 149:139-147.e1. [PMID: 29389337 DOI: 10.1016/j.adaj.2017.10.001] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2017] [Revised: 10/02/2017] [Accepted: 10/04/2017] [Indexed: 11/29/2022]
Abstract
BACKGROUND The primary objective of this systematic review was to investigate the survival of full-coverage restorations fabricated by using digital impressions (DIs) versus that of those fabricated by using conventional impressions. The authors also compared secondary outcomes of marginal and internal fit and occlusal and interproximal contacts. TYPES OF STUDIES REVIEWED The authors conducted a systematic literature search in multiple databases to identify clinical trials with no restrictions by publication type, date, or language. The authors assessed study-level risk of bias and outcome-level strength of evidence. The authors performed a meta-analysis by using a random-effects model. RESULTS Ten studies met the inclusion criteria. The authors identified no studies in which the investigators compared the impression techniques with respect to survival of full-coverage restorations. Mean differences for marginal gap and internal gap were -9.0 micrometers (95% confidence interval, -18.9 to 0.9) and -15.6 μm (95% confidence interval, -42.6 to 11.4), respectively. Studies assessing internal gap were substantially heterogeneous (I2 = 72%; P = .003). CONCLUSIONS AND PRACTICAL IMPLICATIONS Research is lacking to draw robust conclusions about the relative benefits of DIs in terms of restoration survival. Low-quality evidence for marginal fit and internal fit suggested similar performance for both techniques. Evidence quality for interproximal contact and occlusal contact was very low and insufficient to draw any conclusions regarding how the impression techniques compared. Given the uncertainty of the evidence, results should be interpreted with caution. With increasing popularity and adoption of digital scanners by dentists, pragmatic practice-based trials involving standardized, patient-centered outcomes may improve confidence in the comparative effectiveness of DIs.
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Śmielak B, Klimek L, Wojciechowski R, Bąkała M. Effect of zirconia surface treatment on its wettability by liquid ceramics. J Prosthet Dent 2019; 122:410.e1-410.e6. [PMID: 31547953 DOI: 10.1016/j.prosdent.2019.06.021] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2018] [Revised: 06/24/2019] [Accepted: 06/25/2019] [Indexed: 10/25/2022]
Abstract
STATEMENT OF PROBLEM The wettability of the framework by liquid ceramics is important in ensuring a suitable bond between veneering ceramics and zirconia. PURPOSE The purpose of this in vitro study was to examine the dependence of the wetting angle on temperature to determine the transition temperature from nonwettable to wettable states and to calculate the values of the relative wetting forces of the milled surfaces. MATERIAL AND METHODS Fifty zirconia cylinders were divided into 5 groups (n=10) and subjected to the following treatments: milling, grinding, polishing, and airborne-particle abrasion with Al2O3 or SiC. After treatment, the specimens were rinsed, dried, and examined with respect to their wettability by liquid ceramics by using the automated Thermo-Wet test bench. The results were statistically analyzed by an ANOVA (α=.05). RESULTS The most rapid wettability was obtained through airborne-particle abrasion with Al2O3 at 930 °C. Additionally, the highest relative bond strength (with respect to the machined surface) was obtained with Al2O3 abrasion. CONCLUSIONS Because of variations in the wettability of the zirconia surface after different treatment methods, the firing temperature of the ceramic should also vary depending on the type of surface treatment applied. Thus, it is determined individually according to the chosen method.
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Affiliation(s)
- Beata Śmielak
- Assistant Professor, Department of Prosthodontics, Medical University of Lodz, Lodz, Poland.
| | - Leszek Klimek
- Professor, Institute of Materials Science and Engineering, Lodz University of Technology, Lodz, Poland
| | - Rafał Wojciechowski
- Assistant Professor, Institute of Applied Computer Science, Lodz University of Technology, Lodz, Poland
| | - Marcin Bąkała
- Assistant Professor, Institute of Applied Computer Science, Lodz University of Technology, Lodz, Poland
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Rodrigues SB, Franken P, Celeste RK, Leitune VCB, Collares FM. CAD/CAM or conventional ceramic materials restorations longevity: a systematic review and meta-analysis. J Prosthodont Res 2019; 63:389-395. [PMID: 31303569 DOI: 10.1016/j.jpor.2018.11.006] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2018] [Revised: 10/23/2018] [Accepted: 11/09/2018] [Indexed: 11/17/2022]
Abstract
PURPOSE This systematic review and meta-analysis aimed to evaluate the difference in longevity of tooth-supported ceramic prostheses designed by conventional and computer-aided design/computer-aided manufacturing (CAD/CAM) techniques. STUDY SELECTION Two reviewers searched the Web of Science, PubMed, SCOPUS and LILACS databases between 1966 and October 2017. Clinical studies that compared the survival rate of CAD/CAM against conventional restorations were included. RESULTS Eleven randomized controlled trials and three prospective studies were included, n=14. Three types of tooth-supported restorations were searched in the included studies: single crown, multiple-unit and partial ceramic crown. The follow-up of patients in the studies ranged from 24 to 84 months. A total of 1209 restorations had been placed in 957 patients in the included trials, and failures were analyzed by type and material restoration. From a total of 72 restoration failures, the CAD/CAM system resulted in a 1.84 (IC95%: 1.28-2.63) higher risk than conventional manufacturing of ceramic restoration. Nevertheless, when drop-outs were included as a failure risk, the CAD/CAM system resulted in a risk of 1.32 (IC95%: 1.10-1.58). Multilevel analysis of tooth-supported ceramic restorations, considering drop-outs as successes, resulted in rates of 1.48 and 2.62 failures per 100 restoration-years for the controls and CAD/CAM groups, respectively. Considering drop-outs as failures, we found rates of 4.23 and 5.88 failures per 100 restoration-years for the controls and CAD/CAM groups, respectively. CONCLUSIONS The meta-analysis results suggest that the longevity of a tooth-supported ceramic prostheses made by CAD/CAM manufacturing is lower than that of crowns mad by the conventional technique.
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Affiliation(s)
- Stéfani Becker Rodrigues
- Department of Conservative Dentistry, Dental Materials Laboratory, School of Dentistry, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, Brazil
| | - Patrícia Franken
- Department of Conservative Dentistry, Dental Materials Laboratory, School of Dentistry, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, Brazil
| | - Roger Keller Celeste
- Department of Preventive and Social Dentistry, School of Dentistry, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, Brazil
| | - Vicente Castelo Branco Leitune
- Department of Conservative Dentistry, Dental Materials Laboratory, School of Dentistry, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, Brazil
| | - Fabrício Mezzomo Collares
- Department of Conservative Dentistry, Dental Materials Laboratory, School of Dentistry, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, Brazil.
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Juntavee N, Serirojanakul P. Influence of different veneering techniques and thermal tempering on flexural strength of ceramic veneered yttria partially stabilized tetragonal zirconia polycrystalline restoration. J Clin Exp Dent 2019; 11:e421-e431. [PMID: 31275514 PMCID: PMC6599706 DOI: 10.4317/jced.55722] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2019] [Accepted: 04/01/2019] [Indexed: 11/05/2022] Open
Abstract
Background Different technique for ceramic veneering and thermal tempering process are expected to be a reason for alteration in strength of ceramic veneered zirconia. This study evaluates the effect of different veneering technique and varied thermal tempering process on flexural strength of ceramic veneered zirconia. Material and Methods Ceramic veneered zirconia bars (25 mm length, 4 mm width, 0.7&1.0mm of zirconia & ceramic thickness) were prepared from zirconia block (e.max® ZirCAD), sintered at 1500°C for 4 hours, and veneered with ceramics with different techniques including CAD-fused using e.max CAD® (C), Pressed-on using e.max® Zirpress (P), and layering using e.max® ceram (L), with different tempering process through fast (F), medium (M), and slow (L) cooling (n=15). The specimens were determined for flexural strength on a universal testing machine. ANOVA and Bonferroni's multiple comparisons were used to determine for significant difference (α=0.05). Weibull analysis was applied for survival probability, Weibull modulus (m), and characteristics strength (σc). The interfaces were microscopically examined. The phase transformation of zirconia was determined using X ray diffraction. Results The mean±sd (MPa), m, σc of flexural strength were 922.06±83.45, 12.78, 958.32 for CF, 924.26±74.64, 14.28, 959.62 for CM, 930.25±92.42, 11.83, 970.83 for CS, 518.29±59.97, 10.11, 542.97 for PF, 516.50±67.51, 8.75, 539.17 for PM, and 520.51±42.38, 14.59, 544.51 for PS, 604.36±64.09, 11.28, 630.67 for LF, 583.81±56.95, 11.67, 609.81 for LM, 547.33±52.23, 12.19, 569.36 for LS. The flexural strength was significantly affected by veneering technique (p<0.05). No significant effect on flexural strength upon tempering process was evidenced (P >0.05). Phase transformation from t→m related with veneering and tempering procedure. Conclusions Strength of ceramic veneered zirconia associated with different veneering techniques, but not directly related with tempering process. CAD-on ceramic veneering zirconia is benefit for enhancing the strength of ceramic bilayer and was recommended as a method for ceramic veneering zirconia. Key words:CAD-CAM, cooling process, flexural strength, thermal tempering, zirconia.
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Affiliation(s)
- Niwut Juntavee
- Department of Prosthodontics, Faculty of Dentistry, Khon Kaen University, Khon Kaen, Thailand
| | - Pitsinee Serirojanakul
- Division of Biomaterials and Prosthodontics Research, Faculty of Dentistry, Khon Kaen University, Khon Kaen, Thailand
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The Use of the Finite Elements Method (FEM) to Determine the Optimal Angle of Force Application in Relation to Grooves Notched into a Zirconia Coping with the Aim of Reducing Load on a Connection with Veneering Ceramic. BIOMED RESEARCH INTERNATIONAL 2019; 2019:7485409. [PMID: 31355280 PMCID: PMC6634070 DOI: 10.1155/2019/7485409] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/12/2018] [Revised: 03/15/2019] [Accepted: 05/22/2019] [Indexed: 11/20/2022]
Abstract
Objective of Study To investigate, using the FEM, the influence of different notching angles on a zirconium dioxide coping with the aim of establishing the optimal connection conditions with veneering ceramic. Materials and Methods To calculate the stresses in the connection between zirconia coping and veneering ceramic, a model comprising grooves cut perpendicular was adopted. Such a notch profile was used to design the shape and spacing of the grooves on an FEM model simulating a zirconium dioxide coping. For discretization purposes we used twenty-node solid BRICK elements featuring intermediate nodes with three degrees of freedom in each node. The model was divided into 117 745 finished elements and 439 131 nodes. The problem was solved with a GLU type contact. The same load F = 1N divided by the number of nodes on the external surface was applied to each node of the outer surface of the base. In subsequent computing variants the F load changed the orientation by angle α from 0° to 45° every 15°. Results The highest level of material strain occurs at angle α = 0° σred max =309 MPa and the lowest at angle α = 45° σred max =220 MPa. The highest positive stress pressure occurs at angle α = 0° pmax=251 MPa, pmin=-354 MPa and the lowest at angle α = 15°, pmax=171 MPa, pmin=-186 MPa. In the case of tangential stresses on the coping-veneering ceramic connection, the highest values were noted at angle α = 15° τmax=44,4 MPa and the lowest at angle α = 45° τmax=32,7 MPa. Conclusions To reduce the load on the zirconia-veneering ceramic connection, the notches should be made at an angle of α = 45°.
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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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Cheng CW, Yang CC, Yan M. Bond strength of heat-pressed veneer ceramics to zirconia with various blasting conditions. J Dent Sci 2019; 13:301-310. [PMID: 30895138 PMCID: PMC6388831 DOI: 10.1016/j.jds.2018.03.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2017] [Revised: 03/13/2018] [Indexed: 11/29/2022] Open
Abstract
Background/purpose With the technology of dental prostheses and materials progress, the bond durability of the all-ceramic restoration system plays an important role in the oral environment. The purpose of this study was to evaluate the influence of the parameters of blasting on the shear bond strength between zirconia and pressed veneer ceramics. Materials and methods Zirconia was blasted with different alumina particle size subjected to two types of applied pressures. Heat-pressed and layered veneer ceramic blocks were served as an experimental group and control group, respectively. The shear strength of specimens after thermocycling for 20,000 times was also investigated to simulate oral environment. Results The results indicated that the surface roughness was increased significantly (P < 0.05) with increasing particle size of alumina and blasting pressure. The alumina particle size had statistically significant influence (P < 0.05) on shear strength of heat-pressed groups. Among heat-pressed ceramic specimens, the highest and lowest shear strength could be obtained when 50 μm of alumina was used at pressure of 0.3 MPa and 110 μm of alumina was used at 0.5 MPa, respectively. The negligible effect of thermal cycle on shear strength of heat-pressed groups can be seen. Conclusion Blasting with 50 μm of alumina at 0.3 MPa could enhance the bond strength between zirconia and veneer ceramics.
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Affiliation(s)
- Chih-Wen Cheng
- Department of Prosthodontics, Chi Mei Hospital, No.901, Zhonghua Rd., Yongkang Dist., Tainan City 710, Taiwan
| | - Chun-Chuan Yang
- Department of Dental Technology, Shu Zen Junior College of Medicine and Management, No.452, Huanqiu Rd. Luzhu Dist., Kaohsiung City 82144, Taiwan
| | - Min Yan
- Institute of Oral Sciences, Chung Shan Medical University, 110, Sec. 1, Jianguo N. Road, Taichung 402, Taiwan
- Department of Dentistry, Chung Shan Medical University Hospital, Chung Shan Medical University, 110, Sec. 1, Jianguo N. Road, Taichung 402, Taiwan
- Corresponding author. Institute of Oral Science, Chung Shan Medical University, 110, Sec. 1, Jianguo N. Road, Taichung 402, Taiwan. Fax: +886-4-24759065.
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Cantner F, Cacaci C, Mücke T, Randelzhofer P, Hajtó J, Beuer F. Clinical performance of tooth- or implant-supported veneered zirconia single crowns: 42-month results. Clin Oral Investig 2019; 23:4301-4309. [PMID: 30887188 DOI: 10.1007/s00784-019-02878-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2018] [Accepted: 03/11/2019] [Indexed: 11/29/2022]
Abstract
OBJECTIVES The objective of this clinical study was to compare and assess the clinical performance of tooth-supported and implant-supported zirconia single crowns with sintered veneering caps. METHODS In this prospective study, 118 patients with a total of 220 single crowns placed on 106 teeth (69 vital teeth, 37 endodontically treated teeth) and 114 implants in molar and premolar regions were examined during a mean observation period of 42 months. The restorations were evaluated for technical failures such as veneering porcelain fractures (chipping), surface quality, marginal fit, and the interface quality of the coping and sintered veneering. The soft tissue status was assessed using the modified Silness and Löe's plaque and gingival index (mPI) and the modified Muhlemann sulcus bleeding index (mSBI). Tooth-supported crowns were checked for secondary caries and hypersensitivity during the follow-up period. Recalls were performed every 6 months. RESULTS The 3-year Kaplan-Meier success probability was 98.2% and 100% for implant- and tooth-supported crowns, respectively. A significant difference could be detected between the implant-supported and tooth-supported zirconia single crowns, in terms of their chipping rate (p = 0.039). Veneering material fractures were recorded on two implant-supported restorations (1.8%). No veneering fractures occurred on tooth-supported single crowns. The plaque and gingival index and sulcus bleeding index showed stable and healthy soft peri-implant and periodontal tissues. Neither loss of vitality nor secondary caries occurred on tooth-supported crowns. CONCLUSIONS Zirconia-based single crowns with a sintered veneering cap showed promising clinical results on both tooth and implant abutments; however, the dental implants were more prone to complications. In terms of clinical significance, high-strength ceramic with a sintered veneering cap can be recommended for prosthetic treatment of both tooth- and implant-supported single crowns in molar regions. CLINICAL RELEVANCE This study provides valuable information for further application of all-ceramic restorations.
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Affiliation(s)
| | - Claudio Cacaci
- Private Dental Office, Weinstraße 4, 80333, Munich, Germany
| | - Thomas Mücke
- Department of Oral and Maxillofacial Surgery, St. Josefshospital, Kurfürstenstr. 69, 47829, Krefeld-Uerdingen, Germany
| | | | - Jan Hajtó
- Private Dental Office, Briennerstrße 7, 80333, Munich, Germany
| | - Florian Beuer
- Department of Prosthodontics, Geriatric Dentistry and Craniomandibular Disorders, University Charité Berlin, Assmannshauser Strasse 4-6, 14197, Berlin, Germany.
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Sorrentino R, Navarra CO, Di Lenarda R, Breschi L, Zarone F, Cadenaro M, Spagnuolo G. Effects of Finish Line Design and Fatigue Cyclic Loading on Phase Transformation of Zirconia Dental Ceramics: A Qualitative Micro-Raman Spectroscopic Analysis. MATERIALS 2019; 12:ma12060863. [PMID: 30875849 PMCID: PMC6470560 DOI: 10.3390/ma12060863] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/27/2019] [Revised: 02/28/2019] [Accepted: 03/12/2019] [Indexed: 11/16/2022]
Abstract
Objectives: Stresses produced during the fabrication of copings and by chewing activity can induce a tetragonal-to-monoclinic (t–m) transformation of zirconia. As a consequence, in the m-phase, the material is not able to hinder possible cracks by the favorable mechanism known as “transformation toughening”. This study aimed at evaluating if different marginal preparations of zirconia copings can cause a premature phase transformation immediately after manufacturing milling and after chewing simulation. Methods: Ninety copings using three commercial zirconia ceramics (Nobel Procera Zirconia, Nobel Biocare Management AG; Lava Classic, 3M ESPE; Lava Plus, 3M ESPE) were prepared with deep-chamfer, slight-chamfer, or feather-edge finish lines (n = 10). Specimens were tested in a chewing simulator (CS-4.4, SD Mechatronik) under cyclic occlusal loads simulating one year of clinical service. Raman spectra were acquired and analyzed for each specimen along the finish lines and at the top of each coping before and after chewing simulation, respectively. Results: Raman analysis did not show any t–m transformation both before and after chewing simulation, as the typical monoclinic bands at 181 cm−1 and 192 cm−1 were not detected in any of the tested specimens. Conclusions: After a one-year simulation of chewing activity, irrespective of preparation geometry, zirconia copings did not show any sign of t–m transformation, either in the load application areas or at the margins. Consequently, manufacturing milling even in thin thickness did not cause any structural modification of zirconia ceramics “as received by manufacturers” both before and after chewing simulation.
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Affiliation(s)
- Roberto Sorrentino
- Department of Neurosciences, Reproductive and Odontostomatological Sciences, Division of Prosthodontics and Digital Dentistry, University of Naples "Federico II", via S. Pansini 5, 80131 Naples, Italy.
| | - Chiara Ottavia Navarra
- Department of Medical Sciences, University of Trieste, Piazza dell'Ospitale 1, 34129 Trieste, Italy.
| | - Roberto Di Lenarda
- Department of Medical Sciences, University of Trieste, Piazza dell'Ospitale 1, 34129 Trieste, Italy.
| | - Lorenzo Breschi
- Department of Biomedical Science and Neuromotor Sciences, DIBINEM, University of Bologna, Via San Vitale 59, 40123 Bologna, Italy.
| | - Fernando Zarone
- Department of Neurosciences, Reproductive and Odontostomatological Sciences, Division of Prosthodontics and Digital Dentistry, University of Naples "Federico II", via S. Pansini 5, 80131 Naples, Italy.
| | - Milena Cadenaro
- Department of Medical Sciences, University of Trieste, Piazza dell'Ospitale 1, 34129 Trieste, Italy.
| | - Gianrico Spagnuolo
- Department of Neurosciences, Reproductive and Odontostomatological Sciences, Division of Prosthodontics and Digital Dentistry, University of Naples "Federico II", via S. Pansini 5, 80131 Naples, Italy.
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Lümkemann N, Eichberger M, Stawarczyk B. Different surface modifications combined with universal adhesives: the impact on the bonding properties of zirconia to composite resin cement. Clin Oral Investig 2019; 23:3941-3950. [PMID: 30756181 DOI: 10.1007/s00784-019-02825-z] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2018] [Accepted: 01/17/2019] [Indexed: 01/07/2023]
Abstract
OBJECTIVE The purpose of this study was to analyze the impact of plasma treatment and (universal adhesives) UAs on the bonding properties of zirconia. MATERIAL AND METHODS Zirconia specimens (N = 744; n = 186/pretreatment) were prepared, highly polished, and pretreated: (i) plasma (oxygen plasma, 10s, 5 mm), (ii) airborne-particle abrasion (alumina, 50 μm, 0.05 MPa, 5 s, 10 mm), (iii) airborne-particle abrasion + plasma, and (iv) without pretreatment (highly polished surface). Surface roughness (Ra) and surface free energy (SFE) were measured (n = 6/pretreatment). Tensile bond strength (TBS) specimens (n = 180/pretreatment) were further divided (n = 18/conditioning): Clearfil Ceramic Primer (PCG), All-Bond Universal (ABU), Adhese Universal (AU), Clearfil Universal Bond (CUB), G-Premio Bond (GPB), Futurabond U (FBU), iBond Universal (IBU), One Coat 7 Universal (OCU), Scotchbond Universal (SBU), and no conditioning. PCG was luted with Panavia F2.0 and the remaining groups with DuoCem. After storage in distilled water (24 h; 37 °C) and thermocycling (5000×; 5 °C/55 °C), TBS was measured and fracture types (FTs) were determined. Data were analyzed using univariate ANOVA with a partial eta square (ƞP2), the Kruskal-Wallis H, the Mann-Whitney U, and the Chi2 test (P < .05). RESULTS Plasma treatment resulted in an increase of SFE but had no impact on Ra. Airborne-particle abrasion resulted in the highest Ra and a higher TBS when compared with plasma and non-treatment. SBU and AU obtained a higher TBS when compared with PCG. OCU, FBU, ABU, IBU, and GPB indicated comparable TBS to PCG. CUB revealed the lowest TBS. CONCLUSIONS Plasma treatment cannot substitute airborne-particle abrasion when bonding zirconia but MDP-containing adhesives are essential for successful clinical outcomes. CLINICAL RELEVANCE Airborne-particle abrasion with a low pressure (0.05 MPa) in combination with UAs promotes the clinical success of adhesively bonded zirconia restorations.
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Affiliation(s)
- Nina Lümkemann
- Research Associate of Dental Material Unit, Department of Prosthetic Dentistry, University Hospital, Ludwig-Maximilians-University, Munich, Germany
| | - Marlis Eichberger
- Dental Technician of Dental Material Unit, Department of Prosthetic Dentistry, University Hospital, Ludwig-Maximilians-University, Munich, Germany
| | - Bogna Stawarczyk
- Scientific Head of Dental Material Unit, Department of Prosthetic Dentistry, University Hospital, Ludwig-Maximilians-University, Munich, Germany. .,Department of Prosthetic Dentistry, University Hospital, Ludwig-Maximilians-University Munich, Goethestrasse 70, 80336, Munich, Germany.
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Her SB, Kim KH, Park SE, Park EJ. The effect of zirconia surface architecturing technique on the zirconia/veneer interfacial bond strength. J Adv Prosthodont 2018; 10:259-264. [PMID: 30140391 PMCID: PMC6104496 DOI: 10.4047/jap.2018.10.4.259] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2017] [Revised: 02/03/2018] [Accepted: 05/08/2018] [Indexed: 11/30/2022] Open
Abstract
PURPOSE The purpose of this study was to evaluate the effect of the zirconia surface architecturing technique (ZSAT) on the bond strength between veneering porcelain and zirconia ceramic. MATERIALS AND METHODS 20 sintered zirconia ceramic specimens were used to determine the optimal surface treatment time, and were randomly divided into 4 groups based on treatment times of 0, 1, 2, and 3 hours. After etching with a special solution, the surface was observed under scanning electron microscope, and then the porcelain was veneered for scratch testing. Sixty 3 mol% yttria-stabilized tetragonal zirconia polycrystal ceramic blocks were used for tensile strength testing; 30 of these blocks were surface treated and the rest were not. Statistical analysis was performed using ANOVA, the Tukey post-hoc test, and independent t-test, and the level of significance was set at α=.05. RESULTS The surface treatment of the zirconia using ZSAT increased the surface roughness, and tensile strength test results showed that the ZSAT group significantly increased the bond strength between zirconia and veneering porcelain compared to the untreated group (36 MPa vs. 30 MPa). Optimal etching time was determined to be 2 hours based on the scratch test results. CONCLUSION ZSAT increases the surface roughness of zirconia, and this might contribute to the increased interfacial bond strength between zirconia and veneering porcelain.
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Affiliation(s)
- Soo-Bok Her
- Seoul Meerae Dental Clinic, Seoul, Republic of Korea
| | - Kyoung Hun Kim
- Korea Institute of Ceramic Engineering and Technology, Jinju, Republic of Korea
| | - Sang Eun Park
- Restorative Dentistry and Biomaterials Sciences, Harvard School of Dental Medicine, Boston, MA, USA
| | - Eun-Jin Park
- Department of Dentistry, School of Medicine, Ewha Womans University, Seoul, Republic of Korea
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Cheng CW, Chien CH, Chen CJ, Papaspyridakos P. Randomized Controlled Clinical Trial to Compare Posterior Implant-Supported Modified Monolithic Zirconia and Metal-Ceramic Single Crowns: One-Year Results. J Prosthodont 2018. [PMID: 29528175 DOI: 10.1111/jopr.12767] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
PURPOSE The purpose of this randomized controlled clinical trial was to investigate the prosthetic outcomes of posterior implant-supported single crowns (SCs) with a modified monolithic zirconia or metal-ceramic design at 1 year of loading. MATERIALS AND METHODS Forty participants with 73 dental implants in need of at least 1 maxillary or mandibular posterior implant-supported SC were consecutively selected for this study. The included participants were randomly divided into modified monolithic zirconia (MMZ) and metal-ceramic (MC) groups. The implant-supported SCs were examined after 1 year for survival and technical complications. Descriptive statistics were used to illustrate the data, and the association associated risks of complications were estimated using the logistic regression model with Firth's approach for rare outcome (α = 0.05). RESULTS During the observation period, 2 participants in the MC group were lost to follow-up. A total of 38 participants with 70 posterior implant-supported SCs (36 and 34 SCs in the MMZ and MC groups respectively) completed the 1-year follow-up examination. One implant failed in the MMZ group. The 1-year survival rates for implants and crowns were both 97.2% in the MMZ group. The survival rates for implants and crowns were both 100% in the MC group. One screw loosening event was observed in one screw-retained SC in the MMZ group; however, 8 complication events occurred in 7 SCs in the MC group. Therefore, the complication-free rates were 97.1% and 79.4% in the MMZ and MC SCs respectively. The most common complication in the MC group was screw loosening (14.7%), followed by loss of retention (5.9%), and ceramic fracture (2.9%). Significantly more technical complications were observed in the MC SCs than MMZ SCs (p = 0.0432). CONCLUSION The modified monolithic zirconia design applied to the posterior implant-supported SCs had a significantly lower technical complication rate than did the metal-ceramic one.
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Affiliation(s)
- Chih-Wen Cheng
- Division of Prosthodontics, Department of Dentistry, Chi Mei Medical Center, Tainan, Taiwan
| | - Chia-Hui Chien
- Division of Prosthodontics, Department of Dentistry, Chi Mei Medical Center, Liouying, Tainan, Taiwan
| | - Chun-Jung Chen
- Division of Periodontics, Department of Dentistry, Chi Mei Medical Center, Tainan, Taiwan
| | - Panos Papaspyridakos
- Division of Postgraduate Prosthodontics, Tufts University School of Dental Medicine, Boston, MA.,Department of Prosthodontics, Eastman Institute for Oral Health, University of Rochester, Rochester, NY
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Figueiredo VMGD, Pereira SMB, Bressiani E, Valera MC, Bottino MA, Zhang Y, Melo RMD. Effects of porcelain thickness on the flexural strength and crack propagation in a bilayered zirconia system. J Appl Oral Sci 2017; 25:566-574. [PMID: 29069155 PMCID: PMC5806690 DOI: 10.1590/1678-7757-2015-0479] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2016] [Accepted: 03/10/2017] [Indexed: 11/22/2022] Open
Abstract
OBJECTIVE This study evaluated the influence of porcelain (VM9, VITA Zahnfabrik, Germany) thickness on the flexural strength and crack propagation in bilayered zirconia systems (YZ, VITA Zahnfabrik, Germany). MATERIAL AND METHODS Thirty zirconia bars (20.0x4.0x1.0 mm) and six zirconia blocks (12.0x7.5x1.2 mm) were prepared and veneered with porcelain with different thickness: 1 mm, 2 mm, or 3 mm. The bars of each experimental group (n=10) were subjected to four-point flexural strength testing. In each ceramic block, a Vickers indentation was created under a load of 10 kgf for 10 seconds, for the propagation of cracks. RESULTS The results of flexural strength were evaluated by One-way ANOVA and Tukey's test, with a significance level of 5%. The factor "thickness of the porcelain" was statistically significant (p=0.001) and the l-mm group presented the highest values of flexural strength. The cracks were predominant among the bending specimens with 1 and 2 mm of porcelain, and catastrophic failures were found in 50% of 3-mm-thick porcelain. After the indentation of blocks, the most severe defects were observed in blocks with 3-mm-thick porcelain. CONCLUSION The smallest (1 mm) thickness of porcelain on the zirconia infrastructure presented higher values of flexural strength. Better resistance to defect propagation was observed near the porcelain/ zirconia interface for all groups. Higher flexural strength was found for a thinner porcelain layer in a bilayered zirconia system. The damage caused by a Vickers indentation near and far the interface with the zirconia shows that the stress profiles are different.
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Affiliation(s)
- Viviane Maria Gonçalves de Figueiredo
- Univ. Estadual Paulista, Instituto de Ciência e Tecnologia de São José dos Campos, Departamento de Materiais Odontológicos e Prótese, São Jose dos Campos, SP, Brasil
| | - Sarina Maciel Braga Pereira
- Univ. Estadual Paulista, Instituto de Ciência e Tecnologia de São José dos Campos, Departamento de Materiais Odontológicos e Prótese, São Jose dos Campos, SP, Brasil
| | - Eduardo Bressiani
- Univ. Estadual Paulista, Instituto de Ciência e Tecnologia de São José dos Campos, Departamento de Odontologia Restauradora, São Jose dos Campos, SP, Brasil
| | - Márcia Carneiro Valera
- Univ. Estadual Paulista, Instituto de Ciência e Tecnologia de São José dos Campos, Departamento de Odontologia Restauradora, São Jose dos Campos, SP, Brasil
| | - Marco Antônio Bottino
- Univ. Estadual Paulista, Instituto de Ciência e Tecnologia de São José dos Campos, Departamento de Materiais Odontológicos e Prótese, São Jose dos Campos, SP, Brasil
| | - Yu Zhang
- New York University, College of Dentistry, Biomaterials and Biomimetics, New York, USA
| | - Renata Marques de Melo
- Univ. Estadual Paulista, Instituto de Ciência e Tecnologia de São José dos Campos, Departamento de Materiais Odontológicos e Prótese, São Jose dos Campos, SP, Brasil
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Nakamura T, Nakano Y, Usami H, Wakabayashi K, Ohnishi H, Sekino T, Yatani H. Translucency and low-temperature degradation of silica-doped zirconia: A pilot study. Dent Mater J 2017; 35:571-7. [PMID: 27477222 DOI: 10.4012/dmj.2015-274] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The purpose of this study was to examine the translucency and low-temperature degradation of silica-doped experimental Y-TZP (Yttria-stabilized tetragonal zirconia polycrystal) containing almost no alumina. The experimental Y-TZP samples were sintered at either 1,450 or 1,500°C. The samples of commercially available translucent Y-TZP and conventional Y-TZP were used as controls. The contrast ratio (CR) and translucency parameter (TP) were obtained to compare the translucencies. In addition, the specimens were also subjected to an accelerated aging test. The results showed that the experimental Y-TZP sintered at 1,500°C and translucent Y-TZP exhibited almost the same level of translucency. During the accelerated aging test, the translucent Y-TZP underwent a substantial increase in monoclinic content, an index of degradation after the aging test. However, neither the experimental Y-TZP nor the conventional Y-TZP exhibited any appreciable change. It was concluded that the silica-doped Y-TZP will develop translucency and resistance to degradation when sintered at 1,500°C.
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Affiliation(s)
- Takashi Nakamura
- Department of Fixed Prosthodontics, Osaka University Graduate School of Dentistry
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Abstract
Amelogenesis imperfecta (AI) refers to a group of rare genetic disorders that involve tooth development and that are passed down through families as a dominant trait. This condition is characterized by abnormal enamel formation caused by gene mutations that alter the quality and/or quantity of enamel. This dental problem can impact both primary and permanent dentition, varies among affected individuals, and results in esthetic and functional problems. This condition caused the patient in the current case report to have a lack of confidence when speaking. The treatment for amelogenesis imperfecta depends on the severity of the problem and age of the patient. It is crucial to plan a proper remedy, which requires collaboration among dental specialties to execute comprehensive dental treatment in order to provide a long-term solution with adequate esthetics. The current clinical study presents a patient affected by AI that was diagnosed when the patient was a child. The interdisciplinary treatment continued throughout his childhood and into adult life. The initial treatment consisted of resin composite veneers and stainless-steel crowns to restore the defective tooth structure. The malocclusion of the patient was corrected using a fixed orthodontic appliance that was placed when he had an entire permanent dentition. The treatment plan was eventually intended to include all ceramic crowns and veneers.
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Heintze S, Eser A, Monreal D, Rousson V. Using a chewing simulator for fatigue testing of metal ceramic crowns. J Mech Behav Biomed Mater 2017; 65:770-780. [DOI: 10.1016/j.jmbbm.2016.09.002] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2016] [Revised: 08/29/2016] [Accepted: 09/01/2016] [Indexed: 11/26/2022]
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Meirelles PD, Spigolon YO, Borba M, Benetti P. Leucite and cooling rate effect on porcelain-zirconia mechanical behavior. Dent Mater 2016; 32:e382-e388. [PMID: 27707502 DOI: 10.1016/j.dental.2016.09.018] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2015] [Revised: 05/12/2016] [Accepted: 09/03/2016] [Indexed: 10/20/2022]
Abstract
OBJECTIVE This study investigated the influence of the cooling protocol on the mechanical behavior of Y-TZP veneered with porcelain with different compositions. The tested hypotheses were: (1) Y-TZP infrastructures veneered with porcelain containing leucite in its composition presents higher flexural strength (σ) and reliability (m), and (2) slow cooling protocol results in greater σ and m. METHODS A total of 120 bilayer porcelain-Y-TZP bar-shaped specimens were prepared with the dimensions of 1.8mm (0.8mm Y-TZP±1.0mm porcelain)×4.0mm×16.0mm. Specimens were divided into four groups (n=30) according to the porcelain composition (containing or not leucite) and cooling protocol. Fast cooling was performed by opening the furnace chamber at sintering temperature. For the slow cooling, the chamber was maintained closed until it reached the room temperature. Specimens were tested in three-point bending with the porcelain surface under tension using a universal testing machine, in 37°C water, at 0.5mm/min crosshead speed. Data were analyzed by two-way ANOVA, Tukey post-hoc test (α=0.05) and Weibull. RESULTS Y-TZP veneered with porcelains with different microstructural composition presented similar σ and m values (p=0.718). The cooling protocol had no influence on the σ and m values of the experimental groups (p=0.718). Cracking represented 95% of failures, whereas the initial flaw propagated from the porcelain surface towards the interface. SIGNIFICANCE Y-TZP veneered with porcelain containing or not leucite present similar mechanical behavior and, at 1-mm thickness, is not sensitive to the cooling protocol.
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Affiliation(s)
- P D Meirelles
- University of Passo Fundo, Post-Graduate Program in Dentistry, Passo Fundo, RS, Brazil
| | - Y O Spigolon
- University of Passo Fundo, Post-Graduate Program in Dentistry, Passo Fundo, RS, Brazil
| | - M Borba
- University of Passo Fundo, Post-Graduate Program in Dentistry, Passo Fundo, RS, Brazil
| | - P Benetti
- University of Passo Fundo, Post-Graduate Program in Dentistry, Passo Fundo, RS, Brazil.
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Abstract
INTRODUCTION The use of zirconia in medicine and dentistry has rapidly expanded over the past decade, driven by its advantageous physical, biological, esthetic, and corrosion properties. Zirconia orthopedic hip replacements have shown superior wear-resistance over other systems; however, risk of catastrophic fracture remains a concern. In dentistry, zirconia has been widely adopted for endosseous implants, implant abutments, and all-ceramic crowns. Because of an increasing demand for esthetically pleasing dental restorations, zirconia-based ceramic restorations have become one of the dominant restorative choices. Areas covered: This review provides an updated overview of the applications of zirconia in medicine and dentistry with a focus on dental applications. The MEDLINE electronic database (via PubMed) was searched, and relevant original and review articles from 2010 to 2016 were included. Expert commentary: Recent data suggest that zirconia performs favorably in both orthopedic and dental applications, but quality long-term clinical data remain scarce. Concerns about the effects of wear, crystalline degradation, crack propagation, and catastrophic fracture are still debated. The future of zirconia in biomedical applications will depend on the generation of these data to resolve concerns.
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Affiliation(s)
- Yen-Wei Chen
- a Department of Restorative Dentistry , University of Washington School of Dentistry , Seattle , WA , USA
| | - Joelle Moussi
- a Department of Restorative Dentistry , University of Washington School of Dentistry , Seattle , WA , USA
| | - Jeanie L Drury
- a Department of Restorative Dentistry , University of Washington School of Dentistry , Seattle , WA , USA
| | - John C Wataha
- a Department of Restorative Dentistry , University of Washington School of Dentistry , Seattle , WA , USA
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Abstract
Ceramics has become increasingly popular as a dental restorative material because of its superior esthetics, as well as its inertness and biocompatibility. Among dental ceramics, zirconia is used as a dental biomaterial and it is the material of choice in contemporary restorative dentistry. Zirconia ceramics has both clinical popularity and success due to its outstanding mechanical properties and ease of machining in the green stage via computer-aided design and computer-aided manufacturing technology. Zirconia is one of the most promising restorative biomaterial because it has favorable mechanical and chemical properties suitable for medical application. Zirconia ceramics is becoming a prevalent biomaterial in dentistry. Clinical evaluations also indicate a good success rate for zirconia with minimal complications. This article reviews the current literature on dental zirconia with respect to basic properties, biocompatibility, and clinical applications in aesthetic dentistry as single unit crown.
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Affiliation(s)
- Yasser Alfawaz
- Lecturer, Department of Restorative Dental Sciences, College of Dentistry King Saud University, Riyadh, Kingdom of Saudi Arabia, Phone: +96614677420, e-mail:
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Flexural strength and reliability of monolithic and trilayer ceramic structures obtained by the CAD-on technique. Dent Mater 2015; 31:1453-9. [DOI: 10.1016/j.dental.2015.09.013] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2015] [Revised: 07/21/2015] [Accepted: 09/21/2015] [Indexed: 11/19/2022]
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Dogan DO, Gorler O, Mutaf B, Ozcan M, Eyuboglu GB, Ulgey M. Fracture Resistance of Molar Crowns Fabricated with Monolithic All-Ceramic CAD/CAM Materials Cemented on Titanium Abutments: An In Vitro Study. J Prosthodont 2015; 26:309-314. [PMID: 26618513 DOI: 10.1111/jopr.12393] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/29/2015] [Indexed: 11/26/2022] Open
Abstract
PURPOSE To assess the fracture resistance of single-tooth implant-supported crown restorations made with different CAD/CAM blocks. MATERIALS AND METHODS Thirty-six titanium abutments were put on dental implant analogs (Mis Implant). For each of three test groups (n = 12/group), implant-supported, cement-retained mandibular molar single crowns were produced. Crowns were made of lithium disilicate glass (LD) IPS e.max CAD, feldspathic glass ceramic (FEL) Vita Mark II, and resin nano-ceramic (RNC) Lava Ultimate. The crowns were cemented with self-adhesive resin cement RelyX Unicem 2. After chewing cycling, crowns were tested to failure in a universal testing machine. Fracture values were calculated as initial (F-initial) and maximum fracture (F-max). RESULTS The study groups were ranked, in order of having highest value, (LD > FEL) > RNC for F-initial load value and (LD > RNC) > FEL for F-max load value. This demonstrated that there was no parallel change in the F-initial and F-max values presenting the fracture resistance of specimens. CONCLUSIONS There was no accordance between the F-initial and F-max values of the LD, RNC, and FEL after chewing simulation with thermocycling resembling 5 years of clinical functional use. LD had the highest fracture resistance during the fracture test. RNC had low fracture resistance; however, it had considerably high fracture resistance during the fracture test. FEL had considerably low fracture resistance values.
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Affiliation(s)
- Derya Ozdemir Dogan
- Department of Prosthodontics, Cumhuriyet University Faculty of Dentistry, Sivas, Turkey
| | - Oguzhan Gorler
- Department of Prosthodontics, Cumhuriyet University Faculty of Dentistry, Sivas, Turkey
| | - Burcu Mutaf
- Sultanbeyli Oral Health Center, Istanbul, Turkey
| | - Mutlu Ozcan
- University of Zurich, Head of Dental Materials Unit, Center for Dental and Oral Medicine, Clinic for Fixed and Removable Prosthodontics and Dental Materials Science, Zurich, Switzerland
| | - Gunes Bulut Eyuboglu
- Department of Restorative Dentistry, Karadeniz Technical University Faculty of Dentistry, Trabzon, Turkey
| | - Melih Ulgey
- Department of Prosthodontics, Cumhuriyet University Faculty of Dentistry, Sivas, Turkey
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Fracture Strength of Aged Monolithic and Bilayer Zirconia-Based Crowns. BIOMED RESEARCH INTERNATIONAL 2015; 2015:418641. [PMID: 26576423 PMCID: PMC4631855 DOI: 10.1155/2015/418641] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/28/2014] [Accepted: 01/19/2015] [Indexed: 11/18/2022]
Abstract
The purpose of this study was to evaluate the effect of design and surface finishing on fracture strength of yttria-tetragonal zirconia polycrystal (Y-TZP) crowns in monolithic (1.5 mm thickness) and bilayer (0.8 mm zirconia coping and 0.7 mm porcelain veneer) configuration after artificial aging. Bovine incisors received crown preparation and Y-TZP crowns were manufactured using CAD/CAM technique, according to the following groups (n = 10): Polished monolithic zirconia crowns (PM); Glazed monolithic zirconia crowns (GM); Bi-layer crowns (BL). Crowns were cemented with resin cement, submitted to artificial aging in a chewing simulator (2.5 million cycles/80 N/artificial saliva/37°C), and tested for fracture strength. Two remaining crowns referring to PM and GM groups were submitted to a chemical composition analysis to measure the level of yttrium after aging. One-way ANOVA and Tukey's test (P = .05) indicated that monolithic zirconia crowns presented similar fracture strength (PM = 3476.2 N ± 791.7; GM = 3561.5 N ± 991.6), which was higher than bilayer crowns (2060.4 N ± 810.6). There was no difference in the yttrium content among the three surfaces evaluated in the monolithic crowns. Thus, monolithic zirconia crowns present higher fracture strength than bilayer veneered zirconia after artificial aging and surface finishing does not affect their fracture strength.
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Rinke S, Kramer K, Bürgers R, Roediger M. A practice-based clinical evaluation of the survival and success of metal-ceramic and zirconia molar crowns: 5-year results. J Oral Rehabil 2015; 43:136-44. [DOI: 10.1111/joor.12348] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/24/2015] [Indexed: 12/22/2022]
Affiliation(s)
- S. Rinke
- Private Practice; Hanau Germany
- Department of Prosthodontics; Georg-August-University; Göttingen Germany
| | - K. Kramer
- Department of Medical Statistics; Georg-August-University; Göttingen Germany
| | - R. Bürgers
- Department of Prosthodontics; Georg-August-University; Göttingen Germany
| | - M. Roediger
- Department of Prosthodontics; Georg-August-University; Göttingen Germany
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Vigolo P, Mutinelli S, Biscaro L, Stellini E. An In Vivo Evaluation of the Fit of Zirconium-Oxide Based, Ceramic Single Crowns with Vertical and Horizontal Finish Line Preparations. J Prosthodont 2015; 24:603-9. [DOI: 10.1111/jopr.12340] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/20/2015] [Indexed: 11/29/2022] Open
Affiliation(s)
- Paolo Vigolo
- Department of Clinical Odontostomatology; University of Padova; Padova Italy
| | | | | | - Edoardo Stellini
- Department of Clinical Odontostomatology; University of Padova; Padova Italy
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41
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Mainjot AK, Najjar A, Jakubowicz-Kohen BD, Sadoun MJ. Influence of thermal expansion mismatch on residual stress profile in veneering ceramic layered on zirconia: Measurement by hole-drilling. Dent Mater 2015; 31:1142-9. [DOI: 10.1016/j.dental.2015.06.017] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2014] [Revised: 05/16/2015] [Accepted: 06/25/2015] [Indexed: 11/16/2022]
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López-Suárez C, Gonzalo E, Peláez J, Rodríguez V, Suárez MJ. Fracture resistance and failure mode of posterior fixed dental prostheses fabricated with two zirconia CAD/CAM systems. J Clin Exp Dent 2015; 7:e250-3. [PMID: 26155341 PMCID: PMC4483332 DOI: 10.4317/jced.52067] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2014] [Accepted: 02/05/2015] [Indexed: 11/29/2022] Open
Abstract
Background In recent years there has been an improvement of zirconia ceramic materials to replace posterior missing teeth. To date little in vitro studies has been carried out on the fracture resistance of zirconia veneered posterior fixed dental prostheses. This study investigated the fracture resistance and the failure mode of 3-unit zirconia-based posterior fixed dental prostheses fabricated with two CAD/CAM systems. Material and Methods Twenty posterior fixed dental prostheses were studied. Samples were randomly divided into two groups (n=10 each) according to the zirconia ceramic analyzed: Lava and Procera. Specimens were loaded until fracture under static load. Data were analyzed using Wilcoxon´s rank sum test and Wilcoxon´s signed-rank test (P<0.05). Results Partial fracture of the veneering porcelain occurred in 100% of the samples. Within each group, significant differences were shown between the veneering and the framework fracture resistance (P=0.002). The failure occurred in the connector cervical area in 80% of the cases. Conclusions All fracture load values of the zirconia frameworks could be considered clinically acceptable. The connector area is the weak point of the restorations. Key words:Fixed dental prostheses, zirconium-dioxide, zirconia, fracture resistance, failure mode.
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Affiliation(s)
- Carlos López-Suárez
- DDS, Researcher, Department of Buccofacial Prostheses, Faculty of Odontology, University Complutense of Madrid, Spain
| | - Esther Gonzalo
- DDS, PhD, Associate Professor, Department of Buccofacial Prostheses, Faculty of Odontology, University Complutense of Madrid, Spain
| | - Jesús Peláez
- DDS, PhD, Associate Professor, Department of Buccofacial Prostheses, Faculty of Odontology, University Complutense of Madrid, Spain
| | - Verónica Rodríguez
- DDS, Researcher, Department of Buccofacial Prostheses, Faculty of Odontology, University Complutense of Madrid, Spain
| | - María-Jesús Suárez
- MD, DDS, PhD, Professor, Department of Buccofacial Prostheses, Faculty of Odontology, University Complutense of Madrid, Spain
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All-ceramic or metal-ceramic tooth-supported fixed dental prostheses (FDPs)? A systematic review of the survival and complication rates. Part II: Multiple-unit FDPs. Dent Mater 2015; 31:624-39. [PMID: 25935732 DOI: 10.1016/j.dental.2015.02.013] [Citation(s) in RCA: 240] [Impact Index Per Article: 26.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2014] [Revised: 02/24/2015] [Accepted: 02/27/2015] [Indexed: 11/22/2022]
Abstract
OBJECTIVE To assess the 5-year survival of metal-ceramic and all-ceramic tooth-supported fixed dental prostheses (FDPs) and to describe the incidence of biological, technical and esthetic complications. METHODS Medline (PubMed), Embase and Cochrane Central Register of Controlled Trials (CENTRAL) searches (2006-2013) were performed for clinical studies focusing on tooth-supported FDPs with a mean follow-up of at least 3 years. This was complemented by an additional hand search and the inclusion of 10 studies from a previous systematic review [1]. Survival and complication rates were analyzed using robust Poisson's regression models to obtain summary estimates of 5-year proportions. RESULTS Forty studies reporting on 1796 metal-ceramic and 1110 all-ceramic FDPs fulfilled the inclusion criteria. Meta-analysis of the included studies indicated an estimated 5-year survival rate of metal-ceramic FDPs of 94.4% (95% CI: 91.2-96.5%). The estimated survival rate of reinforced glass ceramic FDPs was 89.1% (95% CI: 80.4-94.0%), the survival rate of glass-infiltrated alumina FDPs was 86.2% (95% CI: 69.3-94.2%) and the survival rate of densely sintered zirconia FDPs was 90.4% (95% CI: 84.8-94.0%) in 5 years of function. Even though the survival rate of all-ceramic FDPs was lower than for metal-ceramic FDPs, the differences did not reach statistical significance except for the glass-infiltrated alumina FDPs (p=0.05). A significantly higher incidence of caries in abutment teeth was observed for densely sintered zirconia FDPs compared to metal-ceramic FDPs. Significantly more framework fractures were reported for reinforced glass ceramic FDPs (8.0%) and glass-infiltrated alumina FDPs (12.9%) compared to metal-ceramic FDPs (0.6%) and densely sintered zirconia FDPs (1.9%) in 5 years in function. However, the incidence of ceramic fractures and loss of retention was significantly (p=0.018 and 0.028 respectively) higher for densely sintered zirconia FDPs compared to all other types of FDPs. CONCLUSIONS Survival rates of all types of all-ceramic FDPs were lower than those reported for metal-ceramic FDPs. The incidence of framework fractures was significantly higher for reinforced glass ceramic FDPs and infiltrated glass ceramic FDPs, and the incidence for ceramic fractures and loss of retention was significantly higher for densely sintered zirconia FDPs compared to metal-ceramic FDPs.
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Clinical outcomes of zirconia-based implant- and tooth-supported single crowns. Clin Oral Investig 2015; 20:169-78. [PMID: 25910472 DOI: 10.1007/s00784-015-1479-3] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2014] [Accepted: 04/13/2015] [Indexed: 10/23/2022]
Abstract
OBJECTIVES Zirconia-based restorations have been increasingly used on implant and teeth abutments, but the evidence about clinical outcomes of these restorations is limited. The aim of this study was to assess up to 7-year clinical outcomes of implant- and tooth-supported zirconia-based single crowns. MATERIALS AND METHODS In this retrospective study, 261 patients with 556 single crowns supported by either teeth (324) or implants (232) were examined during 3- to 7-year follow-up (mean observation of 60.70 months for tooth and 59.20 months for implant-supported crowns). California Dental Association (CDA) quality evaluation system was used to evaluate the restorations. Soft tissue status was assessed using plaque and gingival index scores, bleeding on probing, and pocket depth. Patient and professional satisfaction were evaluated by visual analog scale (VAS). RESULTS The 5-year Kaplan-Meier survival probability was 98.3 and 97.3 for implant- and tooth-supported crowns, respectively. In regard to CDA rating, most of the crowns were ranked as either excellent or acceptable (99.5 %). The recorded failures were replacement of the crown due to porcelain chipping (3), implant failure (1), and teeth extraction (5). Soft tissue parameters were not affected by the restorations compare to control teeth. The VAS was high for both patients and clinicians. CONCLUSIONS Zirconia-based single crowns on both tooth and implant abutments showed promising clinical performance in this up to 7-year follow-up. CLINICAL RELEVANCE The zirconia-based single crowns can be used clinically for tooth- and implant-supported restorations.
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45
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Ahmed SN, Donovan TE, Swift EJ. Evaluation of Contemporary Ceramic Materials. J ESTHET RESTOR DENT 2015; 27:59-62. [DOI: 10.1111/jerd.12163] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Sumitha N. Ahmed
- Department of Operative Dentistry; UNC School of Dentistry at Chapel Hill; Chapel Hill NC USA
| | - Terry E. Donovan
- Department of Operative Dentistry; UNC School of Dentistry at Chapel Hill; Chapel Hill NC USA
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Näpänkangas R, Pihlaja J, Raustia A. Outcome of zirconia single crowns made by predoctoral dental students: a clinical retrospective study after 2 to 6 years of clinical service. J Prosthet Dent 2015; 113:289-94. [PMID: 25702968 DOI: 10.1016/j.prosdent.2014.09.025] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2014] [Revised: 09/30/2014] [Accepted: 09/30/2014] [Indexed: 10/24/2022]
Abstract
STATEMENT OF PROBLEM Zirconia has established its role as a reliable ceramic material for fixed prostheses. PURPOSE The purpose of this retrospective study was to evaluate the outcome of zirconia single crowns made by predoctoral students after 2 to 6 years of clinical service. MATERIAL AND METHODS A cohort of 88 patients treated with zirconia single crowns (mean 3 crowns per patient, range 1 to 12 crowns) from 2007 to 2010 by predoctoral dental students was identified. The patients were invited to attend a clinical examination. RESULTS Sixty-six participants (75%) took part in the clinical follow-up (30 women and 36 men; mean age 60.4 years, range 19 to 81 years). Altogether, 190 teeth with single crowns were examined, and the mean follow-up time was 3.88 years (1.85 to 6.04 years). The most common complications were chipping of veneering porcelain (4%) and loss of cementation (4%). The success rate of the zirconia single crowns after 2 to 6 years was 80% and the survival rate 89%. CONCLUSIONS Zirconia crowns can be successfully used in predoctoral dental education. The success rate of zirconia single crowns after 2 to 6 years was 80% and the survival rate was 89%, in accordance with previous studies.
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Affiliation(s)
- Ritva Näpänkangas
- Senior Lecturer, Department of Prosthetic Dentistry and Stomatognathic Physiology, Institute of Dentistry, University of Oulu; and Medical Research Center, Oulu, Oulu University Hospital and University of Oulu, Finland.
| | - Juha Pihlaja
- Research Assistant, Department of Prosthetic Dentistry and Stomatognathic Physiology, Institute of Dentistry, University of Oulu; and Medical Research Center, Oulu, Oulu University Hospital and University of Oulu, Finland
| | - Aune Raustia
- Professor, Department of Prosthetic Dentistry and Stomatognathic Physiology, Institute of Dentistry, University of Oulu; and Medical Research Center, Oulu, Oulu University Hospital and University of Oulu, Finland
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Seven-year prospective clinical study on zirconia-based single crowns and fixed dental prostheses. Clin Oral Investig 2014; 19:1137-45. [DOI: 10.1007/s00784-014-1330-2] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2013] [Accepted: 10/03/2014] [Indexed: 11/26/2022]
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48
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Boemicke W, Kappel S, Stober T, Rammelsberg P. Clinical comparison of metal ceramic resin-bonded fixed dental prostheses with a conventional and a mixed retainer design. J Prosthet Dent 2014; 112:472-80. [DOI: 10.1016/j.prosdent.2014.04.025] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2013] [Revised: 04/30/2014] [Accepted: 04/30/2014] [Indexed: 11/26/2022]
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49
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The rehabilitation of an edentulous mandible with a CAD/CAM zirconia framework and heat-pressed lithium disilicate ceramic crowns: A clinical report. J Prosthet Dent 2014; 111:443-7. [DOI: 10.1016/j.prosdent.2013.11.011] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2013] [Revised: 11/21/2013] [Accepted: 11/27/2013] [Indexed: 01/25/2023]
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50
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Chong KKH, Palamara J, Wong RHK, Judge RB. Fracture force of cantilevered zirconia frameworks: an in vitro study. J Prosthet Dent 2014; 112:849-56. [PMID: 24836535 DOI: 10.1016/j.prosdent.2014.04.016] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
STATEMENT OF PROBLEM Little evidence is available showing the effect of connector dimension and cantilever length on the ultimate fracture force of computer-aided design/computer-aided manufacturing (CAD/CAM) zirconia implant frameworks. PURPOSE The purpose of the study was to determine the impact of variations in the cross-sectional dimension of connector sites and variations in the effective cantilever length (load point) on zirconia implant frameworks. This would allow verification of the fracture force with 2 proposed mathematical models. MATERIAL AND METHODS Forty zirconia implant-supported frameworks with 12-mm distal cantilevers were divided into 4 equal test groups (n=10). Connector dimensions (3×5 mm, 3×4 mm) and cantilever loading distance (7 mm, 10 mm) were tested for ultimate fracture force. A 2-way analysis of variance (ANOVA) was used to examine the ultimate fracture force and examine the relationship between connector dimension and ultimate fracture force. The data obtained from all 4 groups were compared and verified with calculations from 2 theoretical mathematical models. RESULTS Two-way ANOVA revealed significant effects for cross-sectional area connector dimension on fracture force (P<.001) and cantilever length (P=.009). No statistically significant interaction was observed between the 2 factors (P=.229). The observed data were consistent with the data from the proposed mathematical models, with group comparisons showing no statistical significance. The largest difference between the mathematical results and mathematical models was in the 7 mm 3×5 mm group of the fixed cantilever bending model (P=.032). The predominant mode of failure was fracture of the zirconia framework, without damage or plastic deformation of the abutment screws or implant analogs. The 10 mm 3×5 mm specimens fractured at a mean load of 923.7 ±234.5 N; the 10 mm 3×4 mm specimens at a mean load of 474.8 ±122.9 N; the 7 mm 3×5 mm specimens at a mean load of 1011.7 ±185.3 N; and the 7 mm 3×4 mm specimens at a mean load of 700.9 ±152.4 N. CONCLUSIONS Zirconia implant frameworks loaded 7 mm from the distal abutment failed at higher fracture loads than specimens loaded 10 mm from the distal abutment. Zirconia implant frameworks with cross-sectional area connector dimensions of 3×5 mm failed at higher fracture loads than specimens with cross-sectional area connector dimensions of 3×4 mm. No statistically significant interaction was observed between the cross-sectional connector area dimension and cantilever length. Calculations from the mathematical models closely approximated the observed data, which supports the use of the mathematical models as a predictor of fracture force.
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Affiliation(s)
- Kenny K H Chong
- Lecturer, Prosthodontics, Restorative Section, Melbourne Dental School, Faculty of Medicine, Dentistry and Health Sciences, University of Melbourne, Melbourne, Australia
| | - Joseph Palamara
- Associate Professor, Dental Materials, Restorative Section, Melbourne Dental School, Faculty of Medicine, Dentistry and Health Sciences, University of Melbourne, Melbourne, Australia
| | - Rebecca H K Wong
- Coordinator for clinical education, General Practice, Melbourne Dental School, Faculty of Medicine, Dentistry and Health Sciences, University of Melbourne, Melbourne, Australia
| | - Roy B Judge
- Associate Professor, Head of Prosthodontics, Restorative Section, Melbourne Dental School, Faculty of Medicine, Dentistry and Health Sciences, University of Melbourne, Melbourne, Australia.
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