A retrospective analysis of 102 zirconia single crowns with knife-edge margins
Statement of problem: Clinical reports of feldspathic porcelain veneered-zirconia crowns placed on teeth with knifeedge marginal finish lines have recently been presented but with data available for only a limited number of crowns in the anterior maxilla. Purpose: This retrospective study evaluated the clinical success and survival of feldspathic porcelain veneered-zirconia crowns fabricated with knife-edge margins in a private practice. Material and methods: One hundred and two teeth (51 anterior, 51 posterior) were prepared with knife-edge margins and restored with feldspathic porcelain veneered-zirconia crowns. The modified California Dental Association (CDA) criteria were used to clinically evaluate subjects recalled between May and December 2010. Data were analyzed with descriptive statistics. Results: The mean follow-up time was 20.9 months (SD, 13.6; range, 10-72). One tooth had to be extracted because of an endodontic problem not related with the restoration, 2 crowns had minor chipping of the veneering porcelain, while no crowns exhibited fracture of the zirconia core. Conclusions: In this retrospective evaluation, feldspathic porcelain veneered-zirconia crowns with knife-edge margins provided clinical performance similar to that reported with other margin designs.