Periodontitis as a risk factor for peri-implantitis: Systematic review and meta-analysis of observational studies

Objectives: To evaluate the scientific evidence from observational studies concerning the risk of peri-implantitis development in periodontally-compromised patients. Source: The search was carried out in Medline, via PubMed, and the Cochrane Library up to March 2018. Study selection: Clinical studies reporting data on periodontitis and peri-implantitis, with confirmed diagnosis of peri-implantitis based on specific parameters (peri-implant probing depth and peri-implant bleeding on probing) and with evaluations of implants with at least 1 year of function were selected. Data: Nineteen articles were included; only two did not show any association between periodontitis and peri-implantitis. Quality analysis of the articles revealed a low risk of bias in most of the studies. Meta-analyses by study design on patient data showed that patients with periodontitis had a 2.29 higher risk of peri-implantitis than patients without periodontitis (95% CI: 1.34-3.24). However, the effect estimate was OR 5.15 (95% CI: -3.35; 13.65; I2: 0%, p=0.887) for cohort studies. A subgroup analysis showed a significant association between peri-implantitis and chronic periodontitis (patient based data: OR=2.89, 95% CI: 1.79-4.00). Meta-analysis by study design on implant data showed that implants in individuals with periodontitis had 2.15 higher chances of having peri-implantitis (95% CI: 1.10; 3.21). However, the effect estimate was OR 3.24 (95% CI: -0.05; 6.53) for cohort studies. Conclusions: This systematic review showed that diagnosis or history of periodontitis was associated with the occurrence of peri-implantitis. However, this association was not observed when only the cohort studies were analyzed. Results should be evaluated with caution due to heterogeneity among the included primary studies.