Comparative Evaluation of the Effect of Different Finish Lines on Fracture Resistance of Zirconia Crowns: A Systematic Review and Meta-Analysis

Abstract

The fracture resistance of zirconia crowns is significantly influenced by the finish line design of tooth preparations. This systematic review and meta-analysis aimed to evaluate the impact of various finish lines, including chamfer, deep chamfer, and shoulder designs, on zirconia crown performance. A comprehensive literature search across multiple databases identified 17 in-vitro studies for inclusion. Fracture resistance was assessed using universal testing machines, with chamfer and deep chamfer finish lines demonstrating higher resistance compared to shoulder designs, although the differences were not statistically significant. Meta-analysis revealed a pooled mean difference favoring chamfer finish lines for improved stress distribution and structural integrity. The heterogeneity observed highlights the influence of factors such as preparation geometry, material thickness, and cementation protocols. The findings suggest that chamfer and deep chamfer finish lines offer mechanical advantages for zirconia crowns, but further clinical studies are necessary to establish definitive guidelines for optimal finish line design in prosthodontic practice.