Influence of implant location on the prevalence of peri-implantitis in patients with periimplantitis: a within-subjects comparison of healthy and peri-implantitis affected implants

The aim of this study was to analyze the influence of implant location on the prevalence of peri-implantitis by within-subjects comparison of healthy and peri-implantitis affected implants in patients with peri-implantitis.To be included for this study, the patient should have at least one peri-implantitis affected implant and one healthy implant. Following clinical and radiographic assessments for peri-implantitis, 56 patients with 89 peri-implantitis affected implants and 249 healthy implants were included in this study. Influences of implant location variables including jaw position, tooth type, tooth position, and tooth adjacent to the implant on the prevalence of peri-implantitis were assessed using a multilevel analysis. Implants placed in the maxillary jaw showed 2 times higher frequency of peri-implantitis than those placed in the mandibular jaw. Implants with absence of adjacent tooth were twice more likely to be affected by peri-implantitis than those with presence of an adjacent tooth. Sub-group analysis for the combination of jaw and position variables revealed that implants in the maxillary anterior position showed significantly higher prevalence rate of peri-implantitis than those in the mandibular anterior position. Within limitations of the present study, patients showed significant increase in the prevalence rate of peri-implantitis when the implant was placed in the maxillary jaw or when tooth adjacent to the implant was absent. In addition, the presence of tooth seemed to provide positive effect on the occurrence of peri-implantitis at the adjacent implant.