Introduction:

Due to the indiscriminate consumption of drugs, many bacteria have begun to show resistance. However, there is more and more research that seeks solutions to this problem, and to achieve this they investigate the medical benefits of certain plants on the oral cavity and its less toxic effect. 10% of the world's plants are used for medicinal purposes. The National Cancer Institute indicates that 67% of drugs originate in nature, and 25% are derived from plants.

Objective:

Determine the inhibitory effect of in vitro growth of the extracts of Plantago major, Eucalyptus globulus and Matricaria chamomilla at different concentrations (100%, 50%, 25% and 12.5%) on strains of Streptococcus mutans (ATCC 25175).

Methods:

Quasiexperimental, in vitro, longitudinal and prospective study. The universe was formed by the strains Streptococcus mutans, and the population by the strains of Streptococcus mutans (ATCC 25175). The sample size was based on the standardized CLSI method. The sample was 10 discs per extract, embedded with 50 uL., placed on Mueller Hinton agar with Streptococcus mutans seeding (ATCC 25175). Inhibition halos measurements were performed at 24 hours. Parametric analysis of variance tests and the Tukey test were used.

Results:

The average inhibitory halo of 0.12% chlorhexidine was 12.76 mm (p = 0.006). The extract of “eucalyptus” at 25% showed significant differences with respect to the other groups (p = 0.040), 50% (p = 0.002) and 100% (p = 0.000).

Conclusions:

The hydroalcoholic extract of Eucalyptus globulus at 100% presented inhibitory effect against Streptococcus mutans (ATCC 25175) in vitro.