Platform-Switching for Cemented Versus Screwed Fixed Dental Prostheses: Reliability and Failure Modes: An In Vitro Study
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Data
2016-08-01
Autores
Anchieta, Rodolfo Brunieira [UNESP]
Machado, Lucas Silveira [UNESP]
Hirata, Ronaldo
Bonfante, Estevam Augusto
Coelho, Paulo G.
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Wiley-Blackwell
Resumo
Purpose: The aim of this study was to evaluate the probability of survival of cemented and screwed three-unit implant-supported fixed dental prostheses (ISFDP) using different implant-abutment horizontal matching configurations (regular vs switching platforms). Methods: One hundred and sixty-eight implants with internal hexagon connection (4 mm diameter, 10 mm length, Emfils; Colosso Evolution System, Itu, SP, Brazil) were selected for this study according to the horizontal implant-abutment matching configuration (regular or switching) and retention method and divided in four groups (n = 21 per group) as follows: 1) regular platform cemented (IRC); 2) or screw-retained (IRS); 3) switched-platform cemented (ISC); or 4) screw-retained (ISS). Regular and platform-switched abutments (Colosso evolution, 4 mm and 3.3 mm, respectively) were torqued, and 84 three-unit metal bridges were fabricated (first molar pontic). Implants were embedded in polymethylmethacrylate resin and subjected to step-stress accelerated life testing in water. Weibull distribution was used to determine the probability of survival for a mission of 100,000 cycles at 400 N (90% two-sided confidence intervals). Polarized light and scanning electron microscopes were used for fractographic analysis. Results: The beta values of 0.50, 1.19, 1.25, and 1.95 for groups IRC, IRS, ISC, and ISS respectively, indicated that fatigue accelerated the failure for all groups, except IRC. The cement-retained groups presented significantly higher probability of survival (IRC -98%, ISC -59%) than screw-retained groups (IRS -23% and ISS -0%). Screw-retained FDPs exclusively failed by abutment-screw fractures, whereas cement-retained presented implant/screw/abutment fractures. Conclusions: The probability of survival of cement-retained ISFDP was higher than screw-retained, irrespective of implant-abutment horizontal configuration.
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dental implant, fatigue, fixed dental prostheses, fractography, reliability, Weibull analysis
Como citar
Clinical Implant Dentistry And Related Research. Hoboken: Wiley-blackwell, v. 18, n. 4, p. 830-839, 2016.