Aim: To evaluate the antibacterial efficacy of green tea extract against two primary colonizers in vitro and to evaluate and compare the antiplaque efficacy in vivo with 0.2% chlorhexidine.
Materials and methods: The minimum inhibitory concentration (MIC) of 0.2% chlorhexidine and green tea were determined in vitro using agar dilution method. A double-blinded, parallel, randomized, 4 day plaque regrowth clinical trial was designed and conducted to determine and compare the antiplaque efficacy of 0.2% chlorhexidine (group1) and green tea (group 2). Thirty subjects (15 males, mean age 31.9 years), participated in the clinical trial, and the plaque index (Silness and Loe 1964) were compared at the 5th day. Statistical analyses for evaluation of plaque growth and comparison between groups were performed by independent t test.
Results: Green tea mouthrinse shows effective antibacterial action against two selected primary colonizers. When compared between groups chlorhexidine hows least MIC. Both groups showed an effective reduction in plaque re-growth. When compared between groups, chlorhexidine showed more plaque control efficacy than green tea, but the results were not statistically significant (p= 0.778).
Conclusion: The findings of this study suggest that green tea shows effective antibacterial against two primary colonizers with an antiplaque action which is comparable with 0.2% chlorhexidine.