Catechin-incorporated dental copolymers inhibit growth of Streptococcus mutans

Objective: to test the inhibitory growth activity of green tea catechin incorporated into dental resins compared to resins containing the broad-spectrum antimicrobial compound chlorhexidine against streptococcus mutans in vitro. material and methods: the minimum inhibitory concentrations (mics) of epigallocatechin-gallate (egcg) and chlorhexidine (chx) were determined according to the microdilution method. resin discs (5 mm × 3 mm) were prepared from bis-gma/tegdma (r1) and bis-gma/ch3bis-gma (r2) comonomers (n=9) containing: a) no drug,b) egcg,c) chx. two concentrations of each drug (0.5× mic and 1× mic) were incorporated into the resin discs. samples were individually immersed in a bacterial culture and incubated for 24 h at 37°c under constant agitation. cell viability was assessed by counting the number of colonies on replica agar plates. statistical analysis was performed using one-way anova,tukey and student t-tests (α=0.05). results: both resins containing egcg and chx showed a significant inhibition of bacterial growth at both concentrations tested (p<0.05). a significantly higher inhibition was observed in response to resins containing chx at 0.5× mic and 1× mic,and egcg at 1× mic when compared to egcg at 0.5× mic. also,egcg at 0.5× mic in r1 had a significantly higher growth inhibition than in r2. conclusions: both egcg and chx retained their antibacterial activity when incorporated into the resin matrix. egcg at 1× mic in r1 and r2 resins significantly reduced s. mutans survival at a level similar to chx. the data generated from this study will provide advances in the field of bioactive dental materials with the potential of improving the lifespan of resin-based restorations.