Evaluation of the antimicrobial activity of some commonly used toothpastes against selected microorganisms

The addition of antimicrobial agents to toothpaste is one possible way of improving the efficacy of mechanical tooth cleaning procedures as well as aiding the control of dental plaque, preventing dental caries and periodontal diseases. Bacterial isolates comprising of Staphylococcus aureus and Streptococcus pyogenes (GPC), Pseudomonas aeruginosa and Escherichia coli (GNB), Bacillus subtilis (GPR) and Candida albicans (a fungus) were exposed to four fluoride containing toothpastes (Oral-B, Colgate, Macleans and Close-up) and a herbal toothpaste (Dabur herbal) at different concentrations, 10mg/ml, 20mg/ml, 40mg/ml, 80mg/ml and 100mg/ml respectively. Their antimicrobial activity was assessed by measuring their zones of inhibition by Agar diffusion method. After 24hours of incubation, Oral-B gave the highest zones of inhibition against the test isolates at the different concentration. Colgate and Close-Up toothpaste gave close zones of inhibition at the different concentrations against the GPC’s. Close-up appeared to be higher with certain variations against GPR, GNB, and the fungus. Dabur herbal gave lower zones of inhibition against test isolates compared to fluoride containing toothpaste. The gram-positive organisms were found to be more susceptible to the different concentrations of the different toothpaste than the gram-negative organisms. Bacillus subtilis was the most susceptible while Pseudomonas aeruginosa was the least susceptible. Moreso, the activity of the various toothpastes increased with increase in concentration. Oral-B had the highest antimicrobial activity, while Dabur herbal toothpaste had the least activity on the selected organisms. Though the fluoride containing toothpaste seems better, they should be used as recommended to prevent dental fluorosis.Keywords: Toothpaste, Antimicrobial agents, Fluoride, and Herba