The effect of the interproximal contour of single external hexagon implant restorations on the prevalence of peri‐implantitis: A retrospective study

Abstract

AbstractPurposeThe objective of this retrospective study was to evaluate the effect of the interproximal contour of single external hexagon implant restorations on the prevalence of peri‐implantitis.Material and MethodsRecords of 96 patients and 148 external hexagon (EH) implants with time in function ranging from 1 to 17 years were included in the study. The most recent clinical and radiographic data were collected from records and the prevalence of peri‐implantitis was defined according to the 2017 World Workshop on the Classification of Periodontal and Peri‐implant Diseases and Conditions. Marginal bone level (MBL), emergence angle (EA), emergence profile (EP), and crown/implant platform horizontal ratio (CIHR) were obtained from periapical radiographs. Dichotomous variables at the patient‐ and implant level were compared with association tests. Mann‐Whitney U‐Test was performed to compare continuous quantitative values between the studied groups. Binomial logistic regression was conducted to identify risk indicators associated with the peri‐implantitis event at the patient‐ and implant level, with the significance level set at 5% for all tests.ResultsNineteen patients (19.2%) and 24 implants (16.2%) with a mean time in function of 5.0 ± 4.7 years were classified as having peri‐implantitis. No statistically significant differences concerning gender, mean age, implant location in the jaw, or time in function were observed between patients with or without peri‐implantitis (p > 0.05). Of 24 implants with peri‐implantitis 10 (41.7%) displayed EA ≤ 30° (16.4%) while 14 (58.3%) presented EA > 30° with no statistical difference between the groups (p > 0.05). No statistically significant associations were identified between EA, EP, or CIHR and the prevalence of peri‐implantitis.ConclusionThe findings seem to indicate that the EA, EP, and CIHR of single restorations over external hexagon implants are not associated with the presence of peri‐implantitis. However, prospective studies with larger samples are required to better ascertain such an association in the long term.