Antimicrobial effects of a novel Triclosan/zinc citrate dentifrice against mixed culture oral biofilms.
OBJECTIVE
To compare the antimicrobial efficacy in vitro of a new fluoride system containing 0.3% Triclosan and 2.0% zinc citrate with a standard fluoride toothpaste against bacteria commonly isolated from dental plaque.


METHODS
Mature biofilms of fixed depth containing ten oral bacterial species were developed in a model system and then exposed to the formulations both in situ and ex situ.


RESULTS
The standard fluoride toothpaste had limited activity against the Gram positive species following 1 and 5 minutes ex situ exposure (p = 0.004 and p = 0.02, respectively) but none against the Gram negative species; also, no overall effect following repeated pulsing in situ was observed. In contrast, viable counts of Gram positive and Gram negative species were markedly reduced following ex situ exposure for 1 and 5 minutes to the new formulation (Gram positive: p = 0.0007 and p = 0.04; Gram negative: p = 0.04 and p = 0.00001, respectively). Counts of Gram positive bacteria were reduced by 99.9% over a 4-day in situ pulsing period, while no Gram negative species were recoverable from the biofilm by day 4.


CONCLUSIONS
The new toothpaste formulation had a broad spectrum of antimicrobial activity against biofilm consortia containing bacteria associated with both dental caries and periodontal diseases.
Finney
Michelle
M
Health Protection Agency, Porton Down, Centre for Applied Microbiology & Research, Salisbury SP4 0JG, UK. michelle.finney@hpa.org.uk
Walker
James T
JT
Marsh
Philip D
PD
Brading
Melanie G
MG
D000891:Anti-Infective Agents, Local / Q000627:therapeutic use*; D018441:Biofilms / Q000187:drug effects*; D002327:Cariostatic Agents / Q000627:therapeutic use; D002626:Chemistry, Pharmaceutical; D019343:Citric Acid / Q000627:therapeutic use*; D015169:Colony Count, Microbial; D003731:Dental Caries / Q000382:microbiology; D003773:Dental Plaque / Q000382:microbiology; D003802:Dentifrices / Q000627:therapeutic use*; D005459:Fluorides / Q000627:therapeutic use; D006090:Gram-Negative Bacteria / Q000187:drug effects; D006094:Gram-Positive Bacteria / Q000187:drug effects; D006801:Humans; D009055:Mouth / Q000382:microbiology*; D010510:Periodontal Diseases / Q000382:microbiology; D013997:Time Factors; D014260:Triclosan / Q000627:therapeutic use*; D015032:Zinc / Q000627:therapeutic use*
D000891:Anti-Infective Agents, Local; D002327:Cariostatic Agents; D003802:Dentifrices; D019343:Citric Acid; D014260:Triclosan; D015032:Zinc; D005459:Fluorides