Interaction Chlorhexidine-Fluoride on de novo Plaque Formation and Fluoride Retention

OBJECTIVE: The aim was to study if there exists an interaction between chlorhexidine (CHX) and fluoride (F) in a mouthrinse solution on: 1) de novo plaque formation, and 2) retention of F in the oral cavity METHODS: 16 healthy subjects participated in a double-blind, cross-over study without any mechanical tooth cleaning. They were asked to rinse their mouth for one minute in the morning and in the evening during 4 days with 10 ml of the following four test solutions: 1) 0.12% CHX+0.2% NaF, 2) 0.2% NaF, 3) 0.12% CHX, and 4) placebo. Plaque was registered on all tooth surfaces in two randomly selected quadrants using the Quigley-Hein index. Directly thereafter, they rinsed during 1 min with 10 ml of the test solution and unstimulated saliva samples were collected (for F analysis) at various time points up to 45 min. RESULTS: The plaque-inhibiting effect was identical for the two CHX-solutions with 0.12% CHX and 0.12% CHX+0.2% NaF vs. placebo (p<0.001) and there was no significant differences between them. The F retention, based on AUC (Area Under the Curve), was the same (NS) for the two F-containing test solutions containing 0.2% NaF and 0.2% NaF+0.12% CHX. CONCLUSIONS: This experimental 4-day study showed no signs of interaction between chlorhexidine and fluoride in a mouthrinse solution with respect to de novo plaque formation or to fluoride retention in the oral cavity. (The products used in the present study were manufactured by Actavis, Stockholm, Sweden).