Is Immunosuppression a Risk Factor for Development of Peri-implantitis? A Retrospective Cohort Analysis

Abstract

The present study aims to identify if immunosuppression is a risk factor for the development of peri-implantitis. A retrospective cohort study design was conducted on patients presenting to the Philadelphia Veterans Affairs (VA) Medical Center for dental implant placement from 2006 to 2013. Medical encounter notes within 3 months of implant placement were used to collect information about patients’ health status, including evaluations of immune system function. Implant status was assessed using dental encounter notes and radiographs from follow-up appointments at 1, 3, 5, and 10 years. Peri-implantitis was defined as radiographic evidence of change in crestal bone level, clinical evidence of bleeding on probing, with or without suppuration.1Electronic medical records of 884 implants were retrospectively analyzed. Descriptive statistics were calculated using the SAS System (SAS Institute Version 9.4, 2002-2012, Cary, NC). The primary predictor variable was immunosuppression. The primary outcome variable was the presence of peri-implantitis. Other study variables assessed included graft at the time of implant placement, diabetes, smoking, gender, and age over 60. Descriptive, univariate, and multivariate regression analyses were performed to measure the association between predictive variables and development of peri-implantitis.Of the 884 implants placed, 205 (23.1%) developed peri-implantitis. Following a multivariate analysis that controlled for diabetes, smoking, gender, and age over 60, immunosuppression was shown to be significantly associated with an increased risk in the presence of peri-implantitis (P = .0071) when compared to implants placed in immunocompetent subjects. The data from this study show that implants placed in immunosuppressed patients were 29.78% more likely to develop peri-implantitis compared to implants placed in immunocompetent patients (OR = 2.229, 95% CI 1.243-3.996). To the best of the authors’ knowledge, no existing literature has demonstrated this significant risk relationship.Following surgical implant placement, adequate function of the immune system's inflammatory response is imperative to target infections and orchestrates wound healing to allow for successful osseointegration of implants. Few studies, however, have directly investigated this nexus at a mechanistic level. In vivo studies in rabbits have indicated that titanium implant placement may up-regulate the immune system's type 2 inflammatory response to inhibit bone resorption markers and promote healing.2 Therefore, in conjunction with the authors' results, immunosuppression could play a significant role in increasing risk of peri-implantitis.Analysis of implants placed at the Philadelphia VA Medical Center revealed an important association between immunosuppression and the development of peri-implantitis. This study shows that immunosuppression may play a role in increasing the development of peri-implantitis. Along with need for further exploration regarding the pathophysiology of this relationship, additional observational and randomized controlled studies are necessary to validate the authors' findings. As implant restoration of edentulous areas is becoming the new standard of care, identification and understanding of associated risks factors are critical to ensure successful implant outcomes.