Effectiveness of a novel experimental herbal toothpaste against bacterial consortium associated with dental caries

To evaluate the effectiveness of an experimental toothpaste based on Hypericum laricifolium Juss. essential oil against a bacterial consortium associated with dental caries.

The antibacterial activity of the essential oil was evaluated by the disk diffusion and microdilution tests against Streptococcus mutans, Streptococcus sanguinis and Streptococcus salivarius. Petri dishes were incubated at 37°C for 24 h. An experimental toothpaste was prepared at a concentration of 201.76 mg/mL. The antibacterial activity of the experimental and six commercial toothpastes were evaluated by agar well-diffusion method. Petri dishes were inoculated with a bacterial consortium prepared with the three strains. 80 mg of the toothpastes were placed in the wells and the Petri dishes were incubated at 37°C for 24 h. The inhibition zones were measured with a digital compass. The differences between the pastas were evaluated with the one-way ANOVA test, with a 5% level of significance.

The essential oil was more effective than 0.12% chlorhexidine in inhibiting the growth of S. mutans (29.02±1.74 mm) and S. sanguinis (21.92±3.43 mm), being more moderate for S. salivarius (17.66±1.11 mm) . In MBC tests, the EO showed complete inhibition of the growth of S. mutans at a concentration of 5% (50.44 mg/mL), 10% (100.88 mg/mL) for S. sanguinis and 2.5% (25.22 mg/mL) for S. salivarius. The experimental toothpaste was effective in inhibiting the growth of the bacterial consortium (31.88±66 mm), having a similar performance to Total Dent, Colgate Total 12, Kolynos® Herbal and Colgate® Herbal (p> 0.05).

The development of an experimental paste based on H. laricifolium Juss. essential oil (0.28% v/v) showed an important antibacterial activity similar to commercial toothpastes against a bacterial consortium of S. mutans, S. sanguinis and S. salivarius. Key words:Antibacterial agents, toothpastes, medicinal plants, Streptococcus mutans, Streptococcus sanguinis, Streptococcus salivarius.