Prevalence of subjects with progressive bone loss at implants

Abstract

Aim: The aim of the present study was to assess the prevalence of subjects with progressive bone loss at implants with a function time of at least 5 years. Material and methods: Radiographs of 1346 patients who had attended annual follow‐up visits at the Brånemark Clinic, Public Dental Services, Gothenburg, Sweden were retrieved. Six hundred and sixty‐two subjects fulfilled the inclusion criteria. Thus, they all had been provided with implant‐supported (Brånemark System® Nobel BioCare, Gothenburg, Sweden) fixed partial or complete dentures or single‐tooth replacements with a documented function time in radiographs of at least 5 years. Implants that demonstrated progressive bone loss to a level of ≥3 threads of an implant were detected. The number of subjects who exhibited one or more implants with progressive bone loss to the threshold level was recorded. Results: Twenty‐eight percent of 662 included subjects had one or more implants with progressive bone loss. A logistic regression analysis revealed that the individuals in this group carried a significantly larger number of implants than the subjects in whom no implants with progressive loss were detected (6 vs. 4.8). Furthermore, >30% of the subjects in the group with progressive bone loss had ≥3 identified implants and that about 33% of all such implants in this group exhibited extensive bone loss. Out of the total 3413 implants included in the study, 423 implants (12.4%) demonstrated progressive bone loss. Conclusion: It is suggested that the prevalence of progressive bone loss at implants assessed from subject‐based data is higher than that evaluated from implant‐based data.