Objective:

To evaluate the antimicrobial and ant-adherent in vitro activity of tannins isolated from Anacardium occidentale Linn. (Cashew) on dental biofilm bacteria.

Material and Methods:

Streptococcus mutans ATCC 25175, Streptococcus mitis ATCC 903, Streptococcus sanguis ATCC 15300, Streptococcus oralis ATCC 10557, Streptococcus salivarius ATCC 7073 and Lactobacillus casei ATCC 9595 samples were used in this study. The tests were performed by the solid medium dilution method to determine the Minimum Inhibitory Concentration (MIC). The Minimum Inhibitory Concentration of Adherence (MICA) of bacteria to glass was determined in the presence of 5% sucrose. As a positive control, 0.12% chlorhexidine gluconate was used.

The substances were tested at concentrations of 1:

1 (pure solution) up to 1:512. Data were analyzed using descriptive statistics and the SPSS software,version 15.0.

Results:

Tannins isolated from Anacardium occidentale Linn. (cashew) formed inhibition halos ranging from 11 to 17 mm in diameter and were capable of inhibiting the growth of bacteria tested at concentrations of 1:4 (S mutans), 1:16 (S mitis), 1:8 (Ssanguis), 1:4 (S oralis), 1:8 (S salivarius) and 1:2 (L casei). The tannin solution was effective in inhibiting the adherence of microorganisms to glass, and its effect on Streptococcus sanguis (1:512) and Lactobacillus casei (1:512) stood out, showing ant-adherent effect at all concentrations tested.

Conclusion:

Tannin isolates produced in vitro antimicrobial and ant-adherent activity on dental biofilm-forming bacteria and can be considered as an alternative treatment in infectious processes in clinical dentistry