Evaluating Complications, Success Rate, and Marginal Bone Loss in Cement- Versus Screw-Retained Single Implant-Supported Zirconia Crowns: A Systematic Review and Meta-Analysis.

This systematic review and meta-analysis aimed to compare marginal bone loss (MBL), bleeding on probing (BOP), and the incidence of complications between cement-retained and screw-retained (SR) single implant-supported zirconia crowns to provide evidence-based guidance for clinicians. A comprehensive search of PubMed/MEDLINE, Scopus, Embase, Google Scholar, and Lilac databases was conducted by two independent reviewers for studies published between January 2000 and March 2024. Studies evaluating the success rates and complications of single zirconia implant crowns with either cement or screw retention were included. Data on complication frequency, types, and overall success rates were extracted and analyzed. A total of 168 cement-retained and 166 SR zirconia crowns from seven studies with follow-ups ranging from 3 to 10 years were included. Meta-analysis of three to six studies per outcome indicated that SR crowns had significantly lower MBL at six months (standardized mean difference (SMD): -0.63; p = 0.002), though no significant differences in MBL were found at one, three, and five years. BOP outcomes were similar between both retention types. Notably, SR restorations demonstrated a 46% reduced risk of complications compared to cement-retained ones (RR: 0.54; p = 0.02). In conclusion, SR implant-supported zirconia crowns are associated with fewer early MBL and complications. However, long-term bone loss and peri-implant mucosal health appear comparable between the two retention methods.