Clinical Performance of Zirconium Implants Compared to Titanium Implants: a Systematic Review and Meta-Analysis of Randomized Controlled Trials

Purpose To quantitatively assess and compare the clinical outcomes, including survival rate, success rate, and peri-implant indices of titanium and zirconium implants in randomized controlled trials. Methods The electronic databases searched included the Cochrane Central Register of Controlled Trials (CENTRAL), Medline via Ovid, EMBASE, and Web of Science. Randomized controlled trials (RCTs) that reported the effects of zirconium implants on primary outcomes, such as survival rate, success rate, marginal bone loss (MBL), and probing pocket depth (PPD), compared to titanium implants were included in this review. Two reviewers independently screened and selected the records, assessed their quality, and extracted the data from the included studies. Results A total of four studies from six publications reviewed were included. Two of the comparative studies were assessed at minimal risk of bias. Zirconium implants may have a lower survival rate (risk ratio (RR) = 0.91, CI [0.82–1.02], P = 0.100, I2 = 0%) and a significantly lower success rate than titanium implants (RR = 0.87, CI [0.78–0.98], P = 0.030, I2 = 0%). In addition, there was no difference between the titanium and zirconium implants in terms of MBL, PPD, bleeding on probing (BOP), plaque index (PI), and pink esthetic score (PES) (for MBL, MD = 0.25, CI [0.02–0.49], P = 0.033, I2 = 0%; for PPD, MD = −0.07, CI [−0.19–0.05], P = 0.250, I2 = 31%). Conclusion Zirconium implants may have higher failure rates due to their mechanical weakness. Zirconium implants should be strictly assessed before they enter the market. Further studies are required to confirm these findings.