Survival of Zirconia Implants: A Systematic Review and Meta-Analysis

Abstract: Aim To assess the clinical outcomes of zirconia implants, namely survival rate and the prevalence of fracture, based on a systematic review of the literature. Material and method An electronic search was conducted in three databases (PubMed, Web of Science, Science Direct), last updated in October 2022. Inclusion criteria were clinical human studies providing information on implant failure rates in any group of patients receiving zirconia dental implants. Log-rank test was used to compare the survival distributions of implants between some groups of variables. Interval survival rate (ISR) and cumulative survival rate (CSR) were calculated. Results Thirty-seven publications were included in the review, with 2941 zirconia implants in 1766 patients, with a mean follow-up of 36.3 ± 22.7 months. There were 182 implant failures, with the great majority of them occurring within the first year after implant installation. Twenty-four implant fractures were reported, most of them in implants of narrow diameter. There was no statistically significant difference of implant failure between the anterior and posterior regions (p = 0.798), nor between maxilla and mandible (p = 0.341), nor between one- and two-piece implants (p = 0.787). The CSR after 10 years was 88.1 %. Conclusion Clinical studies assessing clinical outcomes of zirconia implants in humans have a relatively short mean follow-up time. Zirconia implants present a CSR of 88.1% after 10 years, with most failures happening within the first year after implant installation. Implants of narrow diameter present higher risk of fractures than implants of wider diameter.