Microbial Characteristics of Peri-Implantitis: A Case-Control Study

Background: The aim of this case-control study is to compare oral microbiologic characteristics of patients with healthy peri-implant conditions and patients with peri-implantitis and to explore the influence of various patient-and implant-related factors on microbiologic characteristics. Methods: Peri-implant submucosal microbial samples were collected from 85 patients with peri-implantitis (cases) and from 69 patients with only implants with healthy peri-implant conditions (controls). Samples were analyzed using culturing techniques. Multivariable logistic regression was used to explore the association of disease status and various patient-and implant-related factors (sex, patient age, smoking, number of remaining teeth, percentage of teeth with bone loss, implant function time, implant surface, and presence of plaque) with microbiologic characteristics. Results: Peri-implant disease status was significantly associated with the submucosal presence of Porphyromonas gingivalis (Pg), Prevotella intermedia (Pi), Tannerella forsythia (Tf), and Fusobacterium nucleatum (Fn). The association with disease status was most obvious for Pi (odds ratio [OR]: 15.1; 95% confidence interval [CI]: 5.1 to 45.3) and Tf (OR: 13.3; 95% CI: 5.4 to 32.5). The prevalence of Aggregatibacter actinomycetemcomitans and Staphylococcus species was very low. Conclusions: The periodontal pathogens Pg, Pi, Tf, and Fn are associated with peri-implantitis. A. actinomycetemcomitans and Staphylococcus species do not seem to play an important role in peri-implantitis.