Aim: The aim of this study is to determine the influence of restorative factors on peri-implant bone loss.

Material and methods: The clinical charts and radiographs of patients who received dental implants at the University of Pennsylvania or outside office were reviewed. In total, 1003 implants were studied across 323 patients. Of the total number of implants, 525 were placed in male patients, and 478 were placed in female patients. Information about the restoration including mesial and distal emergence angle of the original restoration, mesial and distal emergence profile (convex/concave/straight), mesial and distal bone loss %, restoration change, platform switched, subcrestal placement, distance between implant and adjacent tooth or implant, adjacent tooth with bone loss at the initial radiograph, and adjacent tooth with bone loss at the final radiograph were also recorded. All distance and angle measurements were made using the distance and angle tools in the Mipacs system.

Results: The mesial and distal emergence angle and emergence profiles did not have a statistically significant effect on marginal bone loss. Platformed switched implants and single unit crowns had a protective effect on bone loss.

Conclusion: From the variables examined in this study, there is not a clear answer of specific restorative factors that lead to peri-implantitis. Although some values were statistically significant, the values were not clinically significant. Due to the retrospective nature of the study, no causation can be attributed. Splinted implants and non-platformed switched implants may lead to more marginal bone loss, but further studies are necessary to confirm this claim.