Comparison of the fracture strength of single unit metal ceramic and monolithic zirconium restorations in the molar region: A systematic review and meta-analysis

Abstract

Abstract Background: Despite the increasing popularity of monolithic zirconia restorations (MZ), metal ceramic restorations (MC) are still considered the gold standard in the posterior region. The aim of this systematic review and meta-analysis was to compare the fracture strengths of single unit MC and MZ in the molar region. Methods: This review was structured based on the Preferred Reporting Items for Systematic Reviews and Meta- Analyses (PRISMA 2020). Literature search was conducted in PubMed and Web of Science databases until November 18, 2022. In vitro studies that evaluated the fracture strength of MC and MZ were included. Statistical analyzes were performed with CMA (Comprehensive Meta-Analysis) program, with a significance level of 0.05. Results:Five of 753 studies were selected. Fracture strengths of MZ and MC did not show a statistically significant difference both tooth (95% CI:-1.589: 2.118, p=0.779, z= 0.280) and implant (95% CI: -2.215: 2.191, p=0.992 z= -0.010) supported restorations. However in tooth supported restorations a significant difference was found in the subgroup analysis considering different abutment materials (P<0.001) and aging treatments (P<0.001). Additionally in implant supported restorations a significant difference was found in subgroup analysis considering different cements (p=0.001) and load speeds (p=0.001). Conclusion:Within the limitations this present study, fracture strengths of MZ and MC did not show a significant difference in implant or tooth supported single unit restorations at posterior region. Clinical relevance: MZ may be an alternative to MC in posterior single restorations. Present results should be interpreted with caution, as included studies were in vitro.