Abstract
This study aimed to assess the fracture resistance of full-coverage crowns fabricated with Zirconiareinforced lithium silicate glass ceramic [Vita Suprinity (VS group)], hybrid ceramic [Vita Enamic (En group)], and high translucency zirconia [Lava Plus high translucency zirconia (Zi(+) group)] at minimal thickness. A total of 120 epoxy cast replicas of prepared maxillary first molars at a uniform reduction of 0.6 mm were fabricated. VS, En, and Zi(+) crowns of 0.6-mm thickness were fabricated and cemented on the respective tooth models. Thermo-mechanical ageing was performed in all groups. Subsequently, static compressive load (CL) and progressively increasing cyclic load (FL) were applied to 20 specimens per each group (CL: n = 20/40; FL: n = 20/40). The data were analyzed using 1-way ANOVA and Fisher LSD post hoc test (alpha = 0.05). There were statistically significant differences in the mean CL and mean FL among the groups (P = .000). VS had the lowest rank in both tests (CL = 1046 N and FL = 485 N), and Zi(+) had a 58% higher value of the CL and 25% lower value of the FL than En (CL = 2662 N and FL = 1310 N). The minimally invasive full coverage crowns fabricated with En and Zi(+) were fracture resistant to the range of human biting forces. Further studies to determine the safe minimal thickness of VS are needed; other relevant clinical parameters of the materials should be determined to confirm their suitability for the fabrication of minimally invasive full-coverage crowns.