The Effect of Finish Line Design on the Fracture Strength of Zirconia Copings.

Statement Of The Problem: One of the major concerns about all ceramic crowns is their fracture resistance.

Purpose: The purpose of this study was to evaluate the effect of two marginal designs (shoulder 90°, shoulder 135°) on the fracture resistance of zirconia copings.

Materials And Method: In this study, 20 brass dies were prepared using milling machine: 10 with 1mm width shoulder 90° marginal design and the other 10 with 1mm width shoulder 135° finish line design.