Impact of Open Proximal Contacts on Peri-Implant Diseases: A Systematic Review and Meta-Analysis

Objectives: The aim of this systematic review and meta-analysis was to evaluate the impact of open proximal contacts on peri-implant tissue changes, specifically marginal bone levels, probing pocket depth, and the incidence of peri-implant diseases. Methods: Electronic databases were searched to identify non-randomized observational studies comparing open and closed proximal contacts. Risk of bias was assessed using the Cochrane Collaboration's tool and data were analyzed with a statistical software. Results: Out of 276 studies initially identified, five met the inclusion criteria, involving 4882 dental implants. Meta-analysis indicated that open proximal contacts were associated with greater, but not statistically significant, marginal bone changes (mean difference (MD) 0.07; 95% confidence interval (CI) −0.09 to 0.24; p = 0.38); probing pocket depths (MD 0.11; 95% CI −0.29 to 0.51; p = 0.59) and a higher incidence of peri-implantitis (relative risk (RR) 1.63; 95% CI 0.88–3.02; p = 0.12) compared to closed contacts. Open proximal contact was associated with a significant increase in incidence of peri-implant mucositis (RR 1.74; 95% CI 1.06–2.86; p = 0.03). Conclusions: Open proximal contacts are associated with increased probing pocket depths and marginal bone changes and could be a risk indicator for peri-implant mucositis. Further research is needed to assess long-term effects and to develop preventive measures.