The effect of (-)-epigallocatechin gallate as an adjunct to non-surgical periodontal treatment: a randomized clinical trial

BACKGROUND: EGCG is proven to be of good effect to relieve periodontal inflammation, but it has not been applied as a local delivery medicine in patients with periodontitis widely. The aim of this clinical trial was to evaluate the adjunctive effect of (-)-epigallocatechin gallate (EGCG) aqueous solution as a coolant during scaling and root planing in the management of chronic periodontitis. METHODS: A double-blind, randomized controlled study was performed on 15 patients with moderate to severe chronic periodontitis. The bilateral maxillary teeth were randomly divided into the test side and the control side on every individual. On the control side, the periodontal therapy was routinely performed. And on the test side, in the process of periodontal therapy, the distilled water in the ultrasonic scaler was replaced with a 5-mg/mL EGCG solution. The probing depth (PPD), clinical attachment level (CAL), bleeding index (BI), gingival index (GI), and plaque index (PI) were recorded at baseline and 6 and 12 weeks after the treatment. RESULTS: PPD, CAL, BI, GI, and PI generally improved after treatment in both groups. At the sixth week and the twelfth week of review, PPD, CAL, GI, and PI had no statistical difference (p >0.05) between the two groups. At the review of the twelfth week, BI on the test side decreased significantly (p <0.05). CONCLUSIONS: Using EGCG solution as the irrigant instead of water has an additional benefit on the bleeding index at the 12-week review. However, the rest clinical parameters had no additional benefit. TRIAL REGISTRATION: ClinicalTrials.gov ChiCTR2000029831, date of registration: Feb 15, 2020. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s13063-022-06298-6.