Early and late implant loss in a university-based periodontal setting: A retrospective analysis on 1821 patients and 2639 implants over a period of 18 years.

The aim of this study was to retrospectively analyze the implant failure rate, not due to peri-implantitis, in periodontally compromised patients rehabilitated with at least one dental implant placed in a specialist university setting over the last 18 years. Records of patients receiving dental implants at the Department of Periodontology, University of Bern, Switzerland, between 2005 and 2022 were analyzed. Data on 1821 patients with 2639 implants were retrieved. Fifty-nine patients experienced implant loss (rate at patient level: 3.2%) out of which 2.1% were early and 1.1% late implant losses, respectively. The majority of the 59 patients were males (68%) and 27.1% were smokers. Eight mm implants were lost with the highest rate (42.4%) followed by 10 mm implants (31.8%). The rate of lost maxillary implants was more than twice as high compared with that of mandibular implants (69.7 vs. 30.3%). Within the study limitations, the implant failure rate in this cohort of patients enrolled in regular supportive periodontal and peri-implant care, was low.