Associations of clinical characteristics and interval between maintenance visits with peri-implant pathology

We investigated the effects of clinical characteristics and the interval between maintenance visits on incidence of peri-implant pathology in a sample of 1,350 patients treated with dental implants (270 cases of peri-implant pathology and 1,080 healthy controls). The chi-square test was used to evaluate differences between cases and controls in the presence of dental plaque, bleeding, peri-implant pockets >4 mm, bone level, and interval between maintenance visits (significance level, 5%). Crude odds ratios (ORs) and attributable fractions were calculated for variables that significantly differed between cases and controls. The variables identified as risk indicators were dental plaque (P < 0.001; OR = 5.2), bleeding (P < 0.001; OR = 5.0), peri-implant pockets >4 mm (P < 0.001; OR = 17.2), bone level (P < 0.001; middle third, OR = 8.4; apical third, OR = 8.6), and interval between maintenance visits (P < 0.001; 1-3 months, OR = 2.9; 3-5 months, OR = 2.1). Attributable fractions revealed a potential reduction in peri-implant pathology of 53-94% after removing exposures to dental plaque (81%), bleeding (80%), peri-implant pockets >4 mm (94%), bone level (88%), and interval between maintenance visits (53-66%). Selected clinical characteristics and the interval between maintenance visits were significantly associated with the incidence of peri-implant pathology.