Abstract
ObjectivesThe aim of this study was to investigate the in vitro fatigue and fracture force of temporary implant-supported anterior crowns made of different materials with different abutment total occlusal convergence (TOC), with/without a screw channel, and with different types of fabrication.Materials and methodsOne hundred ninety-two implant-supported crowns were manufactured (4 degrees or 8 ...
Abstract
ObjectivesThe aim of this study was to investigate the in vitro fatigue and fracture force of temporary implant-supported anterior crowns made of different materials with different abutment total occlusal convergence (TOC), with/without a screw channel, and with different types of fabrication.Materials and methodsOne hundred ninety-two implant-supported crowns were manufactured (4 degrees or 8 degrees TOC; with/without screw channel) form 6 materials (n = 8; 2 x additive, 3 x subtractive, 1 x automix; reference). Crowns were temporarily cemented, screw channels were closed (polytetrafluoroethylene, resin composite), and crowns were stored in water (37 degrees C; 10 days) before thermal cycling and mechanical loading (TCML). Fracture force was determined. Statistics: Kolmogorov-Smirnov, ANOVA; Bonferroni; Kaplan-Meier; log-rank; alpha = 0.05.ResultsFailure during TCML varied between 0 failures and total failure. Mean survival was between 1.8 x 10(5) and 4.8 x 10(5) cycles. The highest impact on survival presented the material (eta(2) = 0.072, p < .001). Fracture forces varied between 265.7 and 628.6 N. The highest impact on force was found for the material (eta(2) = 0.084, p < .001).ConclusionAdditively and subtractively manufactured crowns provided similar or higher survival rates and fracture forces compared to automix crowns. The choice of material is decisive for the survival and fracture force. The fabrication is not crucial. A smaller TOC led to higher fracture force. Manually inserted screw channels had negative effects on fatigue testing.
Altmetric