Bacterial colonization at implant – abutment interface: a systematic review

Background: Although implants have shown to have a high success rate, clinicians are also called upon to encounter numerous complications and failures. Among the numerous reasons of failures, peri-implantitis is reported to account for 10% of the failures. As the oral cavity provides a natural habitat for various micro-organism due to its non-shedding surface, there is some evidence that gram-negative anaerobic rods colonize around the implant leading to peri-implanitis. This colonization is dependent on various factors such as the micro-gap at the implantabutment interface, the precision of fit, degree of micromovement and applied torque. Aim and Objective: The aim of this article is to provide an overview of current literature on bacterial colonization on the implant surface and the influence of different implantabutment designs on bacterial colonization. Material and Methods: An electronic search was conducted using the PubMed (Medline), PubMed central and Google scholar to identify articles published on bacterial colonization at the implant-abutment interface. The following search words were used: microbioleakage at implant-abutment interface, surface characteristics/roughness of implants, bacterial adhesion on dental implants, bacterial colonization at implant abutment surface. The articles included in the review comprises of in vitro studies, in vivo studies, review abstracts and review articles. Results: The total number of articles for the key words” microbioleakage at implantabutment interface” were 29 and for the key words” bacterial colonization at implant abutment interface“ were 17. After considering the inclusive and exclusive criteria, case report, case series and review articles were excluded. 11 articles were considered eligible based on their relevance to the subject. Conclusion: Although micro-gap formation inevitably occurs at the implant-abutment interface. The current literature highlights that the formation of this micro-gap is influenced by the type of implant-abutment design used. Though the results are insignificant, recent in vivo and in vitro studies have proved that external hexagon results in higher micro leakage compared to other connections used .Morse-taper connections shows the least amount of microbial leakage.