Objectives:The aim of the present systematic review was to analyze the survival and com plication rates of zirconiabased and metalceramic implantsupported single crowns (SCs).
Materials and Methods: An electronic MEDLINE search complemented by manual searching was conducted to identify randomized controlled clinical trials, prospective cohort and retrospective case series on implantsupported SCs with a mean followup time of at least 3 years. Patients had to have been clinically examined at the followup visit. Assessment of the identified studies and data extraction was performed independently by two reviewers. Failure and complication rates were analyzed using robust Poisson's regression models to obtain summary estimates of 5year proportions. Results: The search provided 5,263 titles and 455 abstracts, fulltext analysis was performed for 240 articles, resulting in 35 included studies on implantsupported crowns. Metaanalysis revealed an estimated 5year survival rate of 98.3% (95% CI: 96.8-99.1) for metalceramic implant supported SCs (n = 4,363) compared to 97.6% (95% CI: 94.3-99.0) for zirconia implant supported SCs (n = 912). About 86.7% (95% CI: 80.7-91.0) of the metalceramic SCs (n = 1,300) experienced no biological/ technical complications over the entire observation period. The corresponding rate for zirconia SCs (n = 76) was 83.8% (95% CI: 61.6-93.8). The biologic outcomes of the two types of crowns were similar; yet, zirconia SCs exhibited less aesthetic complications than metalceramics. The 5year incidence of chipping of the veneering ceramic was similar between the material groups (2.9% metalceramic, 2.8% zirconia ceramic). Significantly (p = 0.001), more zirconiaceramic implant SCs failed due to material fractures (2.1% vs. 0.2% metalceramic implant SCs). No studies on newer types of monolithic zirconia SCs fulfilled the simple inclusion criteria of 3 years followup time and clinical examination of the present systematic review. Conclusion: Zirconiaceramic implantsupported SCs are a valid treatment alternative to metalceramic SCs, with similar incidence of biological complications and less aesthetic problems. The amount of ceramic chipping was similar between the materialgroups; yet, significantly more zirconia crowns failed due to material fractures.
K E Y W O R D Sbiological, complications, fixed dental prostheses, implant crown, metaanalysis, metal ceramics, success, survival, systematic review, technical, zirconia frameworkThis is an open access article under the terms of the Creative Commons AttributionNonCommercial License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited and is not used for commercial purposes.