IADR Abstract Archives
In Vivo Antimicrobial Efficacy of a 2-step Stannous Fluoride Dentifrice
Objectives: The Plaque Glycolysis and Regrowth Method (PGRM) is an ex vivo assay for assessing the plaque inhibition of dentifrices containing antimicrobial ingredients (J Clin Dent 6: 59, 1995; FDA 21 CFR Part 356 Vol 68: 103, May 30 2003) by assessing plaque acidogenicity and regrowth. High bioavailable stannous fluoride provides significant clinical efficacy for plaque and gingivitis (J Perio 75: 1592-5196, 2004). Objective: To evaluate the antimicrobial efficacy of Crest® Pro-Health HD Daily Two-Step Toothpaste System (HD).
Methods: HD Step1 (0.454%SnF2) and HD Step 2 (H2O2) were evaluated independently in two separate randomized double-blind triple-exposure cross-over PGRM studies. In both studies Crest® Pro Health (CPH: 0.454%SnF2/HMP) was the positive control and Crest® Cavity Protection (CCP: 0.243% NaF) the negative control. Subjects collected baseline plaque samples from the upper dentition then exposed to treatment by swishing with dentifrice for 1min. At 15 and 45 minutes post treatment subjects took additional plaque samples from the lower dentition. Plaque samples were dispersed in 0.03% TSB and normalized to OD600 0.20. Glycolysis inhibition was measured by pH after adding sucrose and incubating at 37oC for 2 hours. Regrowth inhibition was measured by OD after incubating 4hrs in TSB. Change in pH and OD at baseline, 15 and 45min were used to calculate pH response (AUC pH) and regrowth (AUC RG), comparing results across subjects adjusting for baseline.
Results: Study 1 (n=19): AUC pH: HD Step1=28.25a CPH=16.20b CCP=12.38c; AUC RG: HD Step1=13.91a CPH=10.06b CCP=7.32c;
Study 2 (n=15): AUC pH: CPH=17.32a CCP=10.37b HD Step2=2.64c; AUC RG: CPH=9.44a CCP=7.27b HD Step2=4.47c
(a≠b≠c p <0.05 Student's t ).
Conclusions: Stannous Fluoride provided significant in vivo antimicrobial activity suppressing glycolysis and regrowth of plaque. As predicted, Step 2 of the two-step toothpaste system did not show antimicrobial efficacy. PGRM is a useful screen in assessing efficacy of antimicrobial dentifrices.
Methods: HD Step1 (0.454%SnF2) and HD Step 2 (H2O2) were evaluated independently in two separate randomized double-blind triple-exposure cross-over PGRM studies. In both studies Crest® Pro Health (CPH: 0.454%SnF2/HMP) was the positive control and Crest® Cavity Protection (CCP: 0.243% NaF) the negative control. Subjects collected baseline plaque samples from the upper dentition then exposed to treatment by swishing with dentifrice for 1min. At 15 and 45 minutes post treatment subjects took additional plaque samples from the lower dentition. Plaque samples were dispersed in 0.03% TSB and normalized to OD600 0.20. Glycolysis inhibition was measured by pH after adding sucrose and incubating at 37oC for 2 hours. Regrowth inhibition was measured by OD after incubating 4hrs in TSB. Change in pH and OD at baseline, 15 and 45min were used to calculate pH response (AUC pH) and regrowth (AUC RG), comparing results across subjects adjusting for baseline.
Results: Study 1 (n=19): AUC pH: HD Step1=28.25a CPH=16.20b CCP=12.38c; AUC RG: HD Step1=13.91a CPH=10.06b CCP=7.32c;
Study 2 (n=15): AUC pH: CPH=17.32a CCP=10.37b HD Step2=2.64c; AUC RG: CPH=9.44a CCP=7.27b HD Step2=4.47c
(a≠b≠c p <0.05 Student's t ).
Conclusions: Stannous Fluoride provided significant in vivo antimicrobial activity suppressing glycolysis and regrowth of plaque. As predicted, Step 2 of the two-step toothpaste system did not show antimicrobial efficacy. PGRM is a useful screen in assessing efficacy of antimicrobial dentifrices.