Retrospective clinical evaluation of posterior monolithic zirconia restorations after 1 to 3.5 years of clinical service

This retrospective study analyzed clinical outcomes of monolithic zirconia restorations (MZRs) and factors related to restoration success. Patient records were searched to identify those provided MZRs (Cercon ht) for premolars or molars between April 2012 and March 2016. All MZRs were placed according to a standardized protocol. Kaplan-Meier analysis was used to assess MZR performance and failure after recall appointments at 1 year or later. In total, 101 patients received 148 MZRs. Mean duration of follow-up was 25.0 ± 9.9 months. Six MZRs required replacement: three because of pulpal complications, one because of root fracture of an abutment tooth, one because of restoration fracture, and one because the tooth was used as an abutment tooth for a fixed partial denture after root fracture of an adjacent tooth. The cumulative MZR survival (success) rate at 3.5 years was 91.5% (95% confidence interval, 82.1% to 100%). The findings of this short-term retrospective study indicate that posterior MZRs are a therapeutic option for certain patients. In addition, several clinical procedures contribute to MZR success, including preparation design and occlusal and adhesive surface treatments.