Impact of Green Tea (Camellia Sinensis) on periodontitis and caries. Systematic review and meta-analysis

Background: The oral health-promoting effects of green tea are attributed to its polyphenol components. Aim of this work was to systematically review the literature in search for clinical trials assessing green tea for managing periodontitis and caries. Methods: Randomized clinical trials comparing the efficacy of green tea versus control groups in oral hygiene and gingival health; periodontitis; caries; periodontal pathogens number; Streptococcus mutans, Lactobacillus spp. Meta-analysis and meta-regression analysis were performed. Literature searches were carried out using MedLine (PubMed), Scopus, and the Cochrane Library. Eighteen studies (870 subjects) were included. Results: Green tea treatment had medium positive effect size in reducing GI (SMD: 0.50; 95%CI: −0.02/1.01); PI (SMD: 0.54; 95%CI: 0.14/0.95); GBI (SMD: 0.58; 95%CI: −0.41/1.56) and BOP (SMD: 0.52; 95%CI: −0.57/1.60) in respect to the control group. Splitting to subgroups, green tea showed a small neg- ative effect in the chlorhexidine control groups. Green tea treatment had medium positive effect size in reducing CAL (SMD 0.58; 95%CI: −0.49/1.65) and large positive effect size in reducing PPD (SMD:1.02; 95%CI: 0.45/1.59). Conclusion: Even if the results are encouraging, there is insufficient evidence to recommend the use of green tea formulation as first choice treatment for gingivitis, periodontitis and caries.