Interproximal open contacts between implant restorations and adjacent natural teeth as a risk-indicator for peri-implant disease-A cross-sectional study

Objectives: The primary aim of this study was to investigate the relationship between interproximal open contacts and peri-implant disease. The secondary aim was to assess patient-reported outcome measures in relation to contact status.

Materials and methods: A cross-sectional study was performed on 61 patients with 142 implants adjacent to at least one natural tooth. Patients underwent a clinical examination to assess contact status and width, plaque index (PI), gingival index (GI), periodontal probing depths (PPD), and bleeding on probing (BoP). Radiographic marginal bone level was measured in vertical bitewings taken within one year. A diagnosis was given to each implant. Last, subjects completed a brief questionnaire. Rao-scott chi-squared tests and generalized estimating equations (GEE) models were used to compare outcomes between groups.

Results: Seventy-seven (54.2%) implants were found to have ≥1 interproximal open contact. Sixty-five (45.8%) implants had closed contacts only. Implants with interproximal open contacts were significantly associated with peri-implant mucositis and peri-implantitis (p = .003) and increased prevalence of peri-implant disease (adjusted PR = 1.57; 95% CI: 1.09-2.27, p = .015). Open contact status was also associated with higher PPD (p = .045), PI scores (p = .036), and GI scores (p = .021). Open contact prevalence was 75.4% on the patient-level and 54.2% on the implant-level, involving the mesial surface of the implant restorations 68.5% of the time (p < .001).

Conclusion: Interproximal open contacts between implant restorations and adjacent natural teeth are a risk indicator for peri-implant disease. Adequate contact between implant restorations and natural teeth may contribute to the health of peri-implant tissues.