Kanyawat RattanasuwanSupanee RassameemasmaungVanida SangalungkarnChulaluk KomoltriMahidol University2018-12-112019-03-142018-12-112019-03-142016-01-01Odontology. Vol.104, No.1 (2016), 89-9716181255161812472-s2.0-84953354046https://repository.li.mahidol.ac.th/handle/20.500.14594/43595© 2014, The Society of The Nippon Dental University. Green tea catechins had an in vitro antibacterial effect against periodontopathic bacteria and were able to inhibit destruction of the periodontal tissue. In this study, we aimed to evaluate the effect of locally delivered gel containing green tea extract as an adjunct to non-surgical periodontal treatment. Forty-eight subjects who had teeth with probing pocket depth of 5–10 mm were randomly allocated into the test or control group. Probing pocket depth, clinical attachment level, gingival index (GI), bleeding on probing (BOP) and full mouth plaque score were measured at baseline. Subjects received oral hygiene instruction, single episode of scaling and root planing and subgingival application of the green tea gel (test group) or the placebo gel (control group). The gel was repeatedly applied at 1 and 2 weeks later. The parameters were recorded again at the 1st, 3rd and 6th month after the last gel application. The results showed that all parameters were improved in both groups compared to baseline. The test group exhibited significantly higher reduction in BOP at the 3rd month (p = 0.003) and significantly lower GI at the 1st month (p < 0.001) and 3rd month (p < 0.001) when compared with the control group. Thus, green tea gel could provide a superior benefit in reducing bleeding on probing and gingival inflammation when used as an adjunct to non-surgical periodontal treatment. (Trial Registration: MU-IRB 2008/153.0511, ClinicalTrials.gov NCT00918060).Mahidol UniversityDentistryArticleSCOPUS10.1007/s10266-014-0190-1