Retrospective Radiographic Analysis of Peri-Implant Bone Loss in Mandibular Full-Arch Implant Rehabilitations

Can the type of implant rehabilitation influence peri-implant bone loss in case of full-arch mandibular prosthesis? The purpose of the study was to assess, by orthopantomograms (OPG), bone loss around implants in different types of implant-supported prosthetic rehabilitations and evaluate potential risk factors associated with the number and location of implants that may have an association with bone defect. A radiographic study was conducted on 22317 OPGs in the time range from 2010 to 2024. All OPGs with implant-supported prosthetic mandibular rehabilitations were included in the study. A total of 155 OPGs were evaluated, with peri-implant bone loss identified in 64 (41.3%). Distal implants (furthest from the center) across various positioning patterns were most susceptible to bone loss, with positions 3.6 and 4.6 demonstrating the most frequent occurrences (25 and 26 cases, respectively). χ² test revealed significant associations between both implant positioning pattern (p < 0.001) and number of implants (p < 0.001) with peri-implant bone loss. Also by updating the sample of OPGs, increased susceptibility to bone resorption was found for implants placed distal to the mental foramen compared to mesial ones in full-arch implant-supported fixed prostheses. Prospective clinical studies will then be useful to investigate this finding further.