Fracture resistance of highly translucent zirconia laminate veneers with different finish line locations

This in vitro study aimed to evaluate the fracture resistance of maxillary central incisor laminate veneers with different finish line locations, fabricated using four highly translucent zirconia ceramics. Maxillary right central incisor typodonts were prepared with finish lines at equigingival, incisal third, and upper or lower middle third levels. Scanned typodonts were used to fabricate 40 veneers per design from Katana STML (KA), Lava Esthetic (LA), Cercon XT (CE), and ZirCAD MT (ZI) zirconia (n = 10). Additively manufactured resin abutments were used for cementation with dual-polymerising resin cement. Veneers underwent thermocycling (10,000 cycles, 5-55 °C) before load-to-fracture testing. Data were analyzed using two-way ANOVA and Dunnett T3 post hoc tests (α = 0.05). ZI veneers exhibited the highest fracture resistance, while veneers with incisal-third finish lines had the lowest (p ≤ 0.008). CE veneers had lower resistance than KA veneers when the finish line was on the lower middle third (p = 0.029). Equigingival finish led to the highest resistance within LA veneers and led to higher resistance than lower middle third finish lines within ZI veneers (p ≤ 0.014). Overall, ZI veneers demonstrated superior fracture resistance. Although veneers with incisal-third finish lines had the lowest values, all configurations remained within clinically acceptable limits.