An insight performance of zirconia implant abutment: A systematic review and meta-analysis of randomized controlled clinical trial

To determine the clinical performance of zirconia abutment (ZA) by comparing with a titanium abutment (TA) and sub-mucosal-modified zirconia abutment. A systematic search was conducted to retrieve eligible randomised controlled trials (RCTs) from Medline, Cochrane Library, SCOPUS, Embase, Web of Science, and Google Scholar. A search was further divided in two parts. Part I comprises eligible RCTs between zirconia abutment and titanium abutment, and part II included RCTs of zirconia abutment with sub-mucosal modified, pink-veneered glass ceramic versus non-veneered zirconia abutment. Esthetic, biological, and abutment survival was a primary outcome, and technical complications were included as an additional outcome. Fifteen eligible RCTs (Part I: N = 9 and Part II: N = 6) were evaluated, and a total of 362 abutments in 364 subjects were analysed for outcome variables. A sub-group meta-analysis reported no significant difference for Esthetic outcome. However, the overall mean (p =0.03) was higher for zirconia group in those of thin gingival phenotype. Spectrophotometric evaluation of peri-implant mucosal Esthetic does not show any significant difference. Similarly, pink-veneered versus non-veneered group reported no significant difference for thin (<2 mm) and thick (>2 mm) mucosal attachment. Biological outcome does not show any significant difference for comparable groups in both parts. There is marginally lower abutment survival for internally connected zirconia abutment (ZA: 95.4% TA: 100%). Zirconia abutment exhibited excellent Esthetic compared to titanium abutment in those of thin gingival phenotype. Sub-mucosa veneering of zirconia abutment with pink glass ceramic does not show any favourable Esthetic outcome compared to the non-veneered surface.