Clinical efficacy of subgingivally delivered propolis as an adjuvant to nonsurgical periodontal treatment of periodontitis: A systematic review and meta-analysis.

This systematic review and meta-analysis evaluated randomized and nonrandomized studies that assessed the effect of local subgingival propolis as an adjunct to nonsurgical periodontal therapy (NSPT) in the treatment of periodontitis. A detailed search was carried out in Cochrane Library, Embase, LILACS, LIVIVO, PubMed, Scopus, and Web of Science, with no time or language restrictions. A grey literature search was also conducted. The methodology of included studies was evaluated by the Cochrane RoB2 tool. The certainty of each clinical outcome was assessed by the GRADE system. Meta-analyses of mean difference were conducted using the random-effects model, through RevMan 5.4 software. Six studies met the eligibility criteria to be synthesized in the qualitative analysis, and three studies were included in the meta-analysis. The subgingival application of propolis as an adjunct to NSPT improved probing pocket depth (PPD), clinical attachment level (CAL), and bleeding on probing (BOP) in most of the assessed studies. The overall mean difference in PPD reduction was 1.49 mm, 30-45 days after treatment, and 0.8 mm, 90 days after treatment, with very low level of certainty. The overall bias was scored as high risk for all included studies. The adjunctive use of locally delivered propolis associated to NSPT to treat periodontitis may improve periodontal clinical parameters, compared with NSPT alone/placebo. However, the evidence was not strong enough to safely base any clinical recommendation.