Caroliene Meijndert

116 Chapter 7 Abstract Aim : To systematically review literature about the effect of different implant- abutment interface designs on peri-implant bone level changes, implant loss and mid-buccal mucosa changes around single implants placed in the anterior maxilla. Methods : A detailed search was carried out in Pubmed, EMBASE, Cochrane, Scopus, Open Grey and African journals Online (until December 1, 2020). Eligible prospective studies were divided according to the internal implant-abutment configuration: i) platform switched conical (PS-conical), ii) platform switched parallel (PS-parallel) and iii) platformmatched parallel (PM-parallel). Risk of bias was assessed with RoB 2.0 and ROBINS-I. A meta regression analysis was carried out primarily on the pooled peri-implant bone level changes and secondly on implant loss and mid-buccal mucosa level change. The manuscript complied with the PRISMA guidelines and was registered in the PROSPERO database (ID: 225092). Results : A total of 5,513 hits gave 44 eligible articles for the analyses. Bone level change did not differ significantly between the PS-conical and PS-parallel connections, their bone losses were significantly lower compared to the PM connections, only the PS-conical has significant lower implant losses than the PM connections. Mid-buccal mucosa level change was comparable between the three connection configurations. Moderate to high risk of bias was detected in the included studies. Conclusions : The performance of PS-conical and PS-parallel connection configurations are comparable and are accompanied with significantly less bone loss compared to PM-parallel connection configurations. All 3 connection types demonstrated mid-buccal mucosa changes that were small and did not differ significantly amongst the types.