Objective:

To evaluate the progression of caries around orthodontic brackets after the enamel has been exposed to lacteal products containing probiotics.

Methods:

Orthodontic brackets were bonded to the enamel surfaces.

The test specimens were randomly divided into six groups:

G1-negative control; G2-positive control, exposed to culture environment only (without microorganisms); G3-exposed to the cariogenic environment and the fermented cow's milk without probiotic; G4-exposed to the cariogenic environment and fermented cow's milk with probiotic; G5-exposed to the cariogenic environment and yogurt without probiotic; and G6-exposed to the cariogenic environment and yogurt with probiotic. The groups were placed in brain heart infusion medium, supplemented with 2% sucrose and with 1x106 cells/ml of Streptococcus mutans and Streptococcus salivarius (ATCC). The Shapiro-Wilk, Levene, Student t, Kruskal-Wallis, and Mann-Whitney tests were used.

Results:

all groups exposed to the ATCC strains showed lower final microhardness, compared to the negative control (p0.05).

Conclusions:

Lacteal products are not able to prevent the progression of caries around orthodontic brackets.