Comparative Antimicrobial Efficacy of Commercial Dentifrices in Vitro

Objectives: The objective of this study is to compare antimicrobial efficacy of commercially available sodium fluoride dentifrices by utilizing an in-vitro plaque glycolysis assay which measures effects on bacterial metabolism in salivary-derived biofilms.
Methods: Biofilms were grown on actively-attached hydroxyapatite disks with whole saliva in enriched McBain growth media. Post 48hrs of growth, biofilms were treated once with 1:2.5 dentifrice:water slurries for two minutes (n=4 biofilms/treatment). The treated biofilms were then rinsed two times with water and immersed in glycolysis media (0.3% TSB + 0. 5% sucrose, pH 7.2) for 6.5hrs at 37°C. Post incubation in plaque glycolysis media, the metabolic effect of treatment on biofilm was assessed by measuring the pH of immersed glycolysis media post incubation. The experiment was repeated three times. Four commercial dentifrices were tested along with a water control ( I: Sensodyne® (potassium nitrate, 1450ppm fluoride), II: Zendium® (enzymes, zinc gluconate, 1450 ppm fluoride), III: Parodontax® (herbal extracts, sodium bicarbonate, 1400 ppm fluoride), IV:New Colgate Total®(dual zinc plus arginine, 1450 ppm fluoride))
Results: The pH decrease (lesser decrease = less acid produced = more glycolysis inhibition efficacy) was analyzed by ANOVA and p-values for all treatment groups were calculated by Tukey test: water=2.864a, I=2.594b; II=2.574b; III=2.349c; IV=1.590d. Means that do not share a letter are significantly different (p<0.05).
Conclusions: Under the experimental conditions, the New Colgate Total with dual zinc plus arginine showed significantly higher efficacy than commercially available dentifrices in inhibiting plaque metabolism.