A comparative evaluation of the effect of different incisal preparations on the fracture resistance and fracture pattern of mandibular anterior porcelain laminate veneers using two different materials-an in vitro study

Purpose: To evaluate the effect of different incisal preparations on the fracture resistance of mandibular anterior veneers with the use of two routinely indicated ceramics. Method: 35 typodont teeth were randomly allocated to 3 groups according to the design (Group I Leucite reinforced glass ceramic, Group II Lithium disilicate glass ceramic and Group III Control). Veneers were fabricated and cemented using Rely X cement, and were tested under oblique loading to evaluate their fracture resistance and pattern. ANOVA and Post hoc Tukeys test were used to evaluate fracture strength and and Chi square test to evaluate fracture patterns (p<0.01) Results: 1 mm butt joint lithium disilicate group showed significantly higher compressive strength. Conclusion: Both leucite and lithium disilicate may be used to restore mandibular anteriors with the butt joint being the most favourable design.