Chlorhexidine release from orthodontic adhesives after topical chlorhexidine treatment

This study was designed to investigate the ability of orthodontic adhesives to adsorb and release chlorhexidine ( CHX ) after periodic treatment with 1% CHX solution. Composite and resin‐modified glass‐ionomer cement ( RM ‐ GIC ) adhesive disks were incubated with whole saliva or distilled water for 2 h. Release of CHX was measured using high‐performance liquid chromatography after 1, 2, and 5 d of incubation, 1 min after exposure to 1% CHX solution. The CHX measurements were performed in a 5‐d cycle, which was repeated four consecutive times ( n  =   7). The amount of CHX adsorbed and the cumulative amounts of CHX released, with respect to type of adhesive and saliva‐coating, were analyzed using repeated‐measures anova . Chlorhexidine‐adsorbed orthodontic adhesives demonstrated a short‐term release of CHX , which rapidly returned to near‐baseline levels within 3 d. Saliva‐coating did not significantly influence CHX release from RM ‐ GIC , but increased the amount of CHX released from the composite. The amount of CHX released from the composite was 20‐fold higher than that released from the RM ‐ GIC after saliva‐coating. The composite adhesive showed a greater adsorption capacity for CHX than did the RM ‐ GIC , which was more evident after saliva‐coating. This study suggests that composite adhesives may be a significantly more effective CHX reservoir than RM ‐ GIC s in the oral cavity filled with saliva.