Effects of periodontal treatment on the C-reactive protein levels in hemodialysis patients: A systematic review and meta-analysis.

AIM: This systematic review provides a summary of the scientific evidence concerning effects of periodontal treatment on the C-reactive protein (CRP) levels in hemodialysis patients. MATERIAL AND METHODS: Eight databases were accessed until May 2020 for interventional studies which evaluated CRP levels in hemodialysis patients before and after periodontal treatment. Inclusion criteria were studies involving hemodialysis patients with gingivitis or periodontitis, without restriction of year, language, and publication status. Random effects meta-analysis was performed. The risk of bias in eligible studies was assessed using the Joanna Briggs Institute's Critical Appraisal tools for use in systematic reviews. Certainty of evidence was also evaluated using GRADE approach. RESULTS: The search in the databases resulted in 326 records, from which only seven met the eligibility criteria and therefore were submitted to qualitative evaluation. The meta-analysis revealed that, in general, the reduction in CRP levels had moderate and statistically significant effect size (standardized mean difference [SMD] = 0.45; confidence interval [CI] 95% = 0.25, 0.65; p < .001). Statistical heterogeneity was low (I(2) = 0.0%; p = .771). Most studies showed moderate risk of bias. CONCLUSION: Based on low certainty of evidence, the results suggest that periodontal treatment can significantly contribute to reduce CRP levels among hemodialysis patients. However, more randomized clinical studies, with follow-up longer than 12 months, using standardized diagnostic methods and controlling confounding factors, should be performed to strengthen the evidence.