Evaluating the Probability of Survival and Damage Mechanisms of Resin Matrix Ceramics: Insights Into Wear Progression and Surface Damage Under Fatigue

Abstract

Objective: This study evaluated the probability of survival, failure modes, and fatigue-induced wear progression, as well as assessed damage tolerance under simulated mastication in two resin matrix ceramics (polymer-infiltrated ceramic networks (PICN) and resin nanoceramic (RNC)). Methodology: Specimens underwent step-stress accelerated life testing (SSALT) (n = 21), mouth-motion simulation (n = 12), followed by wear analysis and flexural strength testing. Probability of survival and flexural strength were analyzed using Weibull statistical modeling. Damage mechanisms were characterized by optical microscopy, scanning electron microscopy (SEM), and high-resolution 3D quantitative analysis of wear depth and volumetric loss after mouth motion simulation. Two-way ANOVA was used, followed by Tukey Post Hoc with a significance level of 5% (α = 0.05). Results: At 600 N, PICN exhibited significantly lower probability of survival (6%) compared to RNC (60%). SEM images showed delamination and radial cracking for both groups, being more frequent in PICN. Both materials demonstrated progressively significant increases in volumetric wear with the increase in the number of cycles and showed 0.014 mm3 for PICN and 0.016 mm3 for RNC after 100,000. Flexural strength was higher for RNC (303 MPa) than for PICN (189 MPa). Also, it decreased after 1,000 cycles for PICN, while for RNC it decreased only after 100,000 cycles, and it was always higher than for PICN. SEM images showed that fracture originated at wear craters. Conclusions: RNC exhibited superior probability of survival, particularly under more demanding conditions compared to PICN. Both materials showed a progressive increase in surface wear as the number of cycles increased. The flexural strength of RNC remained consistently higher over time. Regarding failure mechanisms, both materials experienced delamination and crack formation; however, radial cracks were more frequently observed in PICN, indicating a higher susceptibility to structural failure under fatigue conditions. Clinical Significance: Selection of restorative materials must balance mechanical performance and long-term durability under functional loading. Resin nanoceramic appears to be a more reliable option than polymer-infiltrated ceramic networks for restorations in high-stress areas, such as posterior teeth or patients with parafunctional habits.