The Impact of Implant–Abutment Connection on Clinical Outcomes and Microbial Colonization: A Narrative Review

Introduction: Osseointegration are often suffering from oral conditions, especially, the micro gap at the implant–abutment connection represents a site for bacterial plaque aggregation, leading to increased inflammatory cells and causing peri-implantitis. Aim: The aim of this narrative review was to describe the different kinds of implant–abutment connections and their ability to reduce bacterial leakage and thus prevent peri-implantitis. Materials and methods: The following databases were consulted: Pubmed, Scopus, Cochrane Library, and Research gate and a total of 528 articles were found. After reading the abstract and titles, 473 items were excluded. The remaining articles (n = 55) were assessed for full-text eligibility. Thirty-three studies were included in the review. Results and Conclusions: We selected 22 clinical trials and 11 reviews, examining a total sample of 2110 implants. From the review, it was clear that there exists a relationship between the implant–abutment interface and bacterial leakage. All the connections presented an amount of micro-gap and bacterial micro-leakage, though conical and mixed connection systems seemed to behave better. Moreover, both connections seemed to have a better load distribution and the mixed system also had anti-rotational properties which are very useful during the positioning of the prosthesis.