Potential risks, treatment strategies, and treatment outcomes of retrograde peri-implantitis: A systematic review

Abstract

Statement of problem

Potential risk factors of retrograde peri-implantitis have been identified from literature reviews; however, only clinical reports or isolated risk factors were evaluated. Retrograde peri-implantitis likely involves multifactorial risks, and outcomes following treatment remain underexplored.

Purpose

The purpose of this systematic review was to identify factors associated with retrograde peri-implantitis occurrence and evaluate outcomes following specific treatment approaches.

Material and methods

A systematic search was performed in PubMed, Cochrane Database of Systematic Reviews, and SCOPUS databases up to December 2024 without language restriction, followed by a manual search. The review followed the population, intervention, control, outcome, study type (PICOS) criteria by including observational human studies on dental implants, with or without prostheses, reporting factors associated with retrograde peri-implantitis occurrence or treatment outcomes following treatment. Retrograde peri-implantitis was defined as progressive bone loss at the implant periapex, with or without clinical symptoms. Exclusion criteria included review articles, case series, and clinical reports, studies lacking a clear definition of retrograde peri-implantitis, or those reporting only retrograde peri-implantitis occurrence. Mixed-population studies were excluded unless retrograde peri-implantitis was clearly reported separately. Clinical outcomes following treatment were assessed, and the risk of bias was assessed using the modified Newcastle-Ottawa scale.

Results

Nine observational studies were evaluated: 2 case-control, 3 retrospective cohort, 1 prospective cohort, and 3 ambispective studies. The ambispective studies collected implant data from dental records of recalled patients and followed up on treatment outcomes after retrograde peri-implantitis management. Occurrence of retrograde peri-implantitis ranged from 0.9% to 23.8%. Higher rates of retrograde peri-implantitis were reported in periapical lesions at the extraction sites or adjacent teeth, periodontitis at the extraction site, and shorter distance between the implant and adjacent teeth. After at least 1-year of follow-up, surgical treatments revealed survival rates of 66.7% to 100%, while the endodontic treatment of the adjacent tooth yielded 49% to 100% survival rates.

Conclusions

Within the limitations of current evidence, the occurrence of retrograde peri-implantitis tended to be associated with periapical lesions of teeth at implant recipient sites and adjacent teeth, exacerbated by close implant proximity to adjacent teeth, and periodontitis at the recipient sites. Comprehensive management of potential risk factors, including surgical intervention for retrograde peri-implantitis-affected implant and endodontic treatment of adjacent teeth with periapical lesions, may improve long-term implant survival.