Analysis of risk factors for early crestal bone loss in osseointegrated, submerged implants prior to restoration.

BACKGROUND: Evidence on the etiology behind bone loss around submerged, prosthetically nonloaded implants is still limited. The long-term stability and success of implants with early crestal bone loss (ECBL), especially when placed as two-stage implants, is uncertain. Hence, the aim of this retrospective study is to analyze the potential patient-level, tooth- and implant-related factors for ECBL around osseointegrated, submerged implants, before restoration as compared with healthy implants with no bone loss. METHODS: Retrospective data were collected from patient electronic health records between 2015 and 2022. Control sites included healthy implants with no bone loss and test sites included implants with ECBL, both of which were submerged. Patient, tooth and implant level data were collected. ECBL was assessed using periapical radiographs obtained during implant placement and second-stage surgeries. Generalized estimating equation logistic regression models were used to account for multiple implants within patients. RESULTS: The total number of implants included in the study was 200 from 120 patients. Lack of supportive periodontal therapy (SPT) was shown to have nearly five-times higher risk of developing ECBL and was statistically significant (p < 0.05). Guided bone regeneration (GBR) procedures before implant placement had a protective effect with an odds ratio of 0.29 (p < 0.05). CONCLUSIONS: Lack of SPT was significantly associated with ECBL, while sites that received GBR procedures prior to implant placement were less likely to exhibit ECBL. Our results underscore the importance of periodontal treatment and SPT for peri-implant health, even when the implants are submerged and unrestored.