Zirconia in fixed prosthodontics: a review of the literature

The purpose of this narrative review is to organize information and knowledge about the properties of the clinical evidence of zirconia-applied dental restorations and to provide relevant information to establish application methods to obtain long-term clinical prognosis of zirconia-applied dental prostheses. From PubMed and manual searches, found "zirconia," "crown," "survival," and "success" keywords were searched. Case reports, case series, reviews, abstracts, in vitro studies, and observational studies were excluded. Additionally, implant superstructures not supported by the periodontal ligament and partially covered crowns were excluded. A total of 42 studies were identified. According to the studies in this review, the most common complication of porcelain-layered zirconia restorations is porcelain fracture, but the long-term prognosis is stable. However, complications of monolithic zirconia restorations include crown fractures and fractures of the abutment tooth and root, and long-term clinical evidence is not available yet. Additionally, bruxism can be a complication factor with both types of restorations, so it is important to carefully examine the oral habits, including bruxism, before treatment. Therefore, the success of zirconia-based restorations in clinical practice requires a careful approach in addition to accurate knowledge of the zirconia material and identification of applicable cases.