Objective:
To assess the fracture load of lithium silicate occlusal veneers reinforced with zirconia at two thicknesses of 0.3 and 0.6 mm, luted to either dentin or enamel, in vitro.
Materials and methods:
Forty human maxillary premolars were randomly distributed into four groups (n = 10): Veneers that are E1-0.3 mm thick, E2-0.6 mm thick, D1-0.3 mm thick, and D2-0.6 mm thick are luted to enamel, dentin, and dentin, respectively. Following the luting processes, the specimens were heated for 5000 thermal cycles (5ºC/55ºC, 1 min dwell period, and 10-second interval) and then submerged in distilled water at 37°C for 7 days. A fracture load test was performed on the specimens in a universal testing apparatus. A one-way ANOVA test along with a post-hoc analysis test was employed to examine the variation in means among many groups. A p-value less than 0.05 was considered significant.
Results:
P < 0.05 indicated that just the thickness component was significant. Fracture load values: E1 (1436.4N ± 242.1); E2 (1119.1N ± 213.9); D1 (1593.6N ± 285.3); and D2 (1237.6N ± 205.5).