Fatigue performance of distinct CAD/CAM dental ceramics

Abstract This study investigated the effect of surface roughness (polished vs. CAD/CAM milling roughness simulation) on the fatigue behavior of five dental ceramics for manufacturing CAD/CAM monolithic restorations. Specimens of five dental ceramics (FC- feldspathic; PICN- polymer-infiltrated ceramic-network; ZLS- zirconia-reinforced lithium silicate glass-ceramic; LD-lithium disilicate glass-ceramic; YZ-yttria-stabilized tetragonal zirconia polycrystal), to be tested under fatigue (12 × 12 × 1.2 mm3), were assigned into two groups according to surface treatment: polished ‘p’ (#2500-grit SiC papers) and CAD/CAM milling roughness simulation ‘gr’ (grinding with #60-grit SiC paper). The fatigue test was performed through the stepwise method (40N–660N; step of 20N; 10,000 cycles/step; 20 Hz frequency). Roughness, topographic and fractographic analyses were performed. The fatigue data were analyzed by Kaplan-Meier and Mantel-Cox (Log rank), and Pearson correlation was used to correlate roughness vs. fatigue data. CAD/CAM milling roughness simulation led to significantly (p