Zirconia Implants as an Alternative to Titanium: A Systematic Review and Meta-Analysis

Purpose: The aim of the present study was to systematically evaluate the marginal bone loss (MBL), success, and survival of zirconia (Zi) implants and compare them with the widely studied titanium (Ti) implants. Materials and Methods: An electronic and manual literature search of several databases was performed by two independent reviewers for articles up to July 2015 that reported the use of Zi implants and survival, success, and MBL with at least 12 months' follow-up. In addition, random effects meta-analyses of selected studies were applied to analyze the weighted mean difference of survival, success, and MBL between groups. Meta-regression analysis was conducted to investigate any potential influence of confounding factors. Results: Twenty-one articles were included, analyzing a total of 1,948 Zi implants with a survival rate of 91.5% and a success rate of 91.6% for 1,250 Zi implants. In addition, three studies were included in the quantitative synthesis and were meta-analyzed for the comparison of survival between Zi and Ti implants, with Zi implants having an 89% greater risk of failure compared with Ti implants (OR = 1.89). There were no statistically significant differences (P = .968) in the success of Zi and Ti implants (odds ratio [OR] = 1.02; 95% confidence interval [CI], 0.47-2.20). MBL (+/- SD) for Zi implants was 0.89 +/- 0.18 mm, which was greater than the MBL for Ti implants (mean difference = 0.14 mm). Also, survival of Zi implants (91.5%) was significantly lower than that of Ti implants (OR = 1.89). Metaregression analysis revealed a similar survival rate for one-piece versus two-piece implants. Similarly, no significant differences were found between immediate and delayed loading. Conclusions: The survival rate of Zi implants was significantly lower than that for the commonly used Ti implants. However, for certain clinical conditions, such as a thin tissue biotype or in the highly esthetic anterior area, Zi implants may offer some benefit when compared with Ti implants.