In vitro Antibacterial Comparison of Dentifrices Claiming Antigingivitis and Gum-healing Properties

Antibacterial activity is a key part of the efficacy of toothpastes currently marketed with gum healing and antigingivitis claims. Prior in vitro testing has shown zinc to be efficacious against organisms associated with caries, supragingival plaque, and gingivitis. Objective: To compare the antibacterial efficacy of prototype antigingivitis toothpastes to currently marketed toothpaste products making gum-related claims, when tested vs. oral microorganisms of significance in an agar dilution MIC test. Methods: All toothpaste samples were placed in identical tubes and submitted blind for testing. The toothpastes were diluted in sterile, deionized water and tested in a twofold dilution series ranging from 0.05 g/mL to 0.0008 g/mL. A toothpaste without antibacterial claims (Crest Regular Paste) was employed as the control. Test organisms were: S. mutans, S. sanguinis, F. nucleatum, A. viscosus and A. naeslundii. Each agar dilution was inoculated with spots of approximately 1 x 105 cfu of each test organism. Plates were incubated at 37°C, aerobically or anaerobically as appropriate. All toothpastes were tested in triplicate vs. each organism. Results: Antibacterial activity was defined by concentration variance from the control. MICs equal to control values were considered non-active. Colgate Total displayed the best activity against the three organisms associated with gum disease. Natural Care Tom’s of Maine Antigingivitis Toothpaste (with and without fluoride) with Zinc Citrate, Viadent Advanced Care, and Listerine Essential Care were superior to control and all equivalent to each other. Jason Healthy Mouth was equivalent to control (no activity), while The Natural Dentist Herbal Toothpaste and Gum Therapy was inferior to control. Conclusion: An all-natural antigingivitis toothpaste with zinc citrate displayed superior antibacterial properties to all other natural brands, equivalency to another zinc citrate product, and equivalency to a four essential oil-based dentifrice.