Assessment of Antagonist Enamel Wear and Clinical Performance of Full-Contour Monolithic Zirconia Crowns: One-Year Results of a Prospective Study.

Purpose: To assess the clinical performance and survival of full-contour monolithic zirconia (MZ) crowns and enamel wear produced over a 1-year period.
Materials and Methods: 60 patients requiring full-coverage restorations for endodontically treated posterior teeth opposed by healthy unrestored antagonistic teeth were selected. MZ crowns were fabricated. Vinyl polysiloxane impressions of the antagonist teeth were made, and the stone casts were digitized using a 3D laser scanner. Wear of the opposing natural teeth was evaluated at baseline (1 week), 6 months, and 1 year after crown cementation. Superimposition of the follow-up scans on the baseline scans were performed to evaluate wear. Survival and function of the restorations were evaluated by the modified USPHS rating criteria at the same timeframes.
Results: Comparison of the baseline and the follow-up wear values was statistically tested using the paired t-test. Statistical significance was noted between the wear values at 6 months (15.5 μm) and at 12 months (16.3 μm) (p < 0.05). The Wilcoxon signed rank sum test was performed to evaluate each parameter of the modified USPHS criteria and to analyze the change in the follow-up scores of the restorations. The survival rate for the crowns was 100%. Results were classified as "excellent" over a 1-year follow up.
Conclusions: MZ crowns showed promising results related to antagonist enamel wear and survival/clinical performance.
(© 2018 by the American College of Prosthodontists.)