Improving the efficacy of chlorhexidine-releasing elastomerics using a layer-by-layer coating technique.

The aims of this study were to identify the optimal concentration of coated orthodontic elastomerics using a layer-by-layer technique that can release chlorhexidine (CHX) as an antimicrobial material, and to measure the physical properties and antimicrobial effects of the coated elastomerics. Ethyl cellulose (EC) was used as the polymer, and five study groups with various combinations of solvents (i.e., ethanol and dichloromethane [DCM]) were included. The coated elastomerics were evaluated with a spectrophotometer to confirm the release of CHX, and their surfaces were observed by SEM. The CHX+EC+DCM group sustained antimicrobial release for the longest period (168 h, p<0.001) and exhibited the largest antimicrobial effect in an inhibition zone test using S. mutans for 7 days (p<0.05). This group had most effective physical properties and antimicrobial effects of coated elastomerics produced using a layerby-layer technique, and so its composition should be considered for use in clinical applications in orthodontics.