A Novel Antimicrobial Nitric Oxide-Releasing Elastomeric Chain

Objectives: Microbial colonization of orthodontic elastomeric chains is a two-fold problem: (1) plaque promotes carious lesions during orthodontic treatment and (2) bacterial by-products can degrade a chain’s mechanical properties. Efforts to combat this colonization have included the development of materials with antimicrobial activity. Recently, biomedical research has focused on the antibacterial properties of S-nitroso-N-acetylpenicillamine (SNAP), a synthetic NO donor that exhibits extended NO release when incorporated into low water-uptake polymers. The objective of this study is to impregnate an orthodontic elastomeric chain with SNAP at three concentrations and evaluate effects on mechanical and physical properties of the chains.
Methods: Elastomeric chains were swelled in 3mL tetrahydrofuran containing concentrations of 75, 125, and 200mg/mL SNAP, respectively. Control chains were swelled in tetrahydrofuran without SNAP. Chains were dried for 48 hours and stored in amber vials.
Results: The experimental elastic chains were successfully impregnated with the SNAP molecule at all three concentrations. Chains impregnated with SNAP exhibited a green color and maintained dimensions after shrinking; however, upon stretching, chains swelled in concentrations of 125 and 200mg/mL broke under tensile stress. Chains swelled in a concentration of 75mg/mL retained their elastic properties. Control chains showed no difference in color or elastic properties.
Conclusions: Elastomeric chains were successfully loaded with three different concentrations of SNAP. However, it appears that a swelling concentration of 75mg/mL may be approaching the upper limit for maintaining mechanical properties, as chains swelled in a higher concentration broke upon stretching. Future studies will test the NO release kinetics of the fabricated chains and evaluate their antimicrobial and mechanical properties.