Marginal adaptation of zirconium dioxide crowns prepared with four different finish lines: An in vitro study

Poor marginal adaptation of zirconia crowns may lead to microleakage, secondary caries and reduced restoration longevity. Marginal integrity is therefore critical for the clinical success of CAD/CAM zirconia crowns. Therefore, it is of interest to evaluate the effect of four finish line designs-rounded shoulder, chamfer, bevelled shoulder, and sloping shoulder-on the marginal fit of zirconia crowns. The rounded shoulder showed superior marginal adaptation compared to chamfer, while bevelled shoulder showed no advantage over sloping shoulder. Rounded shoulder and chamfer finish lines may therefore be more favorable for CAD/CAM zirconia crowns.