Restoration contour is a risk indicator for peri‐implantitis: A cross‐sectional radiographic analysis

AIM: The purpose of this study was to determine whether restoration emergence angle was associated with peri-implantitis. MATERIALS AND METHODS: A data set consisting of 96 patients with 225 implants (mean follow-up: 10.9 years) was utilized. Implants were divided into bone-level and tissue-level groups, and radiographs were analysed to determine the restoration emergence angles, as well as restoration profiles (convex or concave). Peri-implantitis was diagnosed based on probing depth and radiographic bone loss. Associations between peri-implantitis and emergence angles/profiles were assessed using generalized estimating equations. RESULTS: Eighty-three patients with 168 implants met inclusion criteria. The prevalence of peri-implantitis was significantly greater in the bone-level group when the emergence angle was >30 degrees compared to an angle ≤30 degrees (31.3% versus 15.1%, p = .04). In the tissue-level group, no such correlation was found. For bone-level implants, when a convex profile was combined with an angle of >30 degrees, the prevalence of peri-implantitis was 37.8% with a statistically significant interaction between emergence angle and profile (p = .003). CONCLUSIONS: Emergence angle of >30 degrees is a significant risk indicator for peri-implantitis and convex profile creates an additional risk for bone-level implants, but not for tissue-level implants.