A 3-month randomized trial evaluating the effects of stannous fluoride bioavailability on gingivitis.

Purpose: To assess the impact of formulation chemistry on gingivitis effects of two experimental 0.454% stannous fluoride (SnF2) dentifrices with low tin bioavailability versus positive and negative controls.

Methods: Adults with gingivitis were enrolled in this double-blind, parallel group, randomized clinical trial. Gingivitis was assessed with the Löe-Silness Gingivitis Index (LSGI) at baseline, 1 month, and 3 months. The four treatments were: experimental dentifrice A (0.454% SnF2, pH 4.7, soluble tin = 592 ppm), experimental dentifrice B (0.454% SnF2, pH 5.8, soluble tin = 102 ppm), positive control (0.454% SnF2 commercial dentifrice, soluble tin = 2,037 ppm), and negative control (0.76% sodium monofluorophosphate, soluble tin = 0 ppm). Participants brushed for 1 minute twice daily with their assigned dentifrice and a standard manual toothbrush. The primary clinical endpoint was number of gingival bleeding sites. In vitro analyses characterized tin uptake into biofilm and bacterial glycolysis.

Results: Of 120 participants randomized to treatment, 115 completed the study. Baseline mean number of bleeding sites (SD) was 35.11 (17.479). At 1 and 3 months, respectively, the mean was 19.52 and 16.64 for the positive control, 26.91 and 21.71 for Experimental dentifrice A, 31.01 and 27.59 for Experimental dentifrice B, and 33.20 and 29.59 for the negative control. At 1 and 3 months, the positive control showed significantly fewer bleeding sites versus all treatments (P≤ 0.04) and Experimental dentifrice A had significantly less bleeding versus the negative control (P≤ 0.041). Experimental dentifrice B was not significantly different from the negative control (P≥ 0.438) at either timepoint. Tin biofilm uptake and in vitro PGRM exhibited a similar trend.

Clinical significance: SnF2 dentifrice formulation chemistry influences the level of antigingivitis efficacy, which was also reflected in tin bioavailability, tin uptake into biofilm, and bacterial glycolysis inhibition.