Osseointegration of zirconia dental implants in animal investigations: A systematic review and meta-analysis

Objective. To determine the osseointegration rate of zirconium dioxide (ZrO2) dental implants in preclinical investigations. Data. Data on the osseointegration rate was extracted considering the bone to implant contact (BIC), removal torque analysis (RTQ) and push-in tests. Meta analyses were conducted using multilevel multivariable mixed-effects linear regression models. The Sidak method was used in case of multiple testing. Sources. An electronic screening of the literature (MEDLINE/Pubmed, Cochrane Library and Embase) and a supplementary manual search were performed. Animal investigations with a minimum sample size of 3 units evaluating implants made of zirconia (ZrO2) or its composites (ZrO2 > 50 vol.%) were included. Study selection. The search provided 4577 articles, and finally 54 investigations were included and analyzed. Fifty-two studies included implants made from zirconia, 4 zirconia composite implants and 37 titanium implants. In total, 3435 implants were installed in 954 animals. Conclusions. No significant influence of the evaluated bulk materials on the outcomes of interest could be detected. When comparing different animal models, significant differences for the evaluated variables could be found. These results might be of interest for the design of further animal investigations. (C) 2017 The Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.