Objectives: This study compared the antimicrobial activity of commercially available SnF2 dentifrices toward reducing plaque metabolism in vitro.
Methods:To compare antimicrobial actions, the efficacy of formulations can be assessed in plaque growth or metabolism assays (e.g. J Clin Dent 6: 59-70, 1995). Plaque biofilms were prepared on glass rods (N=4/testgroup) with whole saliva spiked TSB as growth media. Following 3 days growth, plaque was treated a single time with 16.7% w/w dentifrice/water slurries for two minutes. Following rinsing plaque was immersed in glycolysis media containing 0.5 % sucrose in TSB pH adjusted to 6.5. Plaque metabolism was followed at 37°C until Bromocresol Purple/Chlorophenol Red (added to neg. ctrl) responded. Metabolic effects of dentifrice treatment were assessed by measuring medium pH post incubation. Treatments: I: Crest® Regular Cavity Protection (NaF, neg. control); II: US Sensodyne Repair & Protect (SnF2) III: Crest Pro-Health (SnF2) IV: Crest Gumcare (positive control – SnF2).
Results:pH decrease in buffer (lesser decrease = more efficacy) by ANOVA comparing groups by Students t test. Letter differences (a≠b≠c) denote statistical significance (p<0.05): I= 2.18a II=1.92b III=1.35c; IV= 1.28c
Conclusions: While Sensodyne Repair & Protect (II) and Crest Pro Health (III) both contain 0.454% Stannous Fluoride as the active, II showed very low efficacy in inhibiting plaque metabolism and III was highly effective indicating that formulation differences are critical in determining bioavailability of stannous fluoride in dentifrice formulations.