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

Area of Science:

• Biomaterials Science
• Orthodontics
• Antimicrobial Coatings

Background:

• Orthodontic elastomerics can harbor bacteria, increasing the risk of oral infections.
• Chlorhexidine (CHX) is a potent antimicrobial agent with potential for incorporation into orthodontic materials.
• Developing effective methods for sustained CHX release from elastomerics is crucial for enhanced oral hygiene during orthodontic treatment.

Purpose of the Study:

• To determine the optimal concentration of CHX-coated orthodontic elastomerics using a layer-by-layer technique.
• To evaluate the physical properties and antimicrobial efficacy of CHX-releasing elastomerics.
• To identify the best solvent combination for maximizing CHX release and antimicrobial effect.

Main Methods:

• Layer-by-layer coating of orthodontic elastomerics with ethyl cellulose (EC) and CHX.
• Utilizing different solvent combinations (ethanol and dichloromethane [DCM]) to create five study groups.
• Assessing CHX release using spectrophotometry and surface morphology via Scanning Electron Microscopy (SEM).
• Evaluating antimicrobial effects through inhibition zone tests against *S. mutans*.

Main Results:

• The CHX+EC+DCM group exhibited sustained CHX release for up to 168 hours (p<0.001).
• This group demonstrated the most significant antimicrobial effect against *S. mutans* over 7 days (p<0.05).
• The CHX+EC+DCM formulation showed superior physical properties and antimicrobial performance compared to other groups.

Conclusions:

• The layer-by-layer technique with CHX, EC, and DCM is effective for creating antimicrobial orthodontic elastomerics.
• The CHX+EC+DCM composition offers sustained CHX release and potent antimicrobial activity.
• This optimized formulation holds promise for clinical application in orthodontics to improve oral hygiene and prevent infections.