Mutans streptococci remained viable on toothbrush bristles, in vivo, for 44 h

Toothbrushes harbor a high number of cariogenic microorganisms.

To investigate the viability of mutans streptococci (MS) on toothbrushes bristles and the production of extracellular polysaccharide (ECP) related to drying time.

Twenty children were submitted to brushing without dentifrice. Toothbrushes were kept at room temperature from 0 to 48 h and then submitted to microbiological processing. The number of MS colonies/biofilms was expressed according to scores: 0=no colonies were detected; 1=1 to 50; 2=51 to 100; 3=over 100. The amount of ECP was evaluated according to scores: 0=absence; 1=ECP recovering until 50% of the surface; 2=ECP recovering more than 50% of the surface. Data were analyzed by Wilcoxon test (α=5%).

At the periods of 0 to 16 h, the toothbrushes had intense bacterial contamination (score 3). From the 18-h, there was a statistically significant decrease in the MS viability (P=0.0078), with predominance of score 1 on periods of 20 to 44 h. The most detected ECP amount was at 0- and 12-h period (P<0.05) with reduction until 32-h period.

Mutans streptococci remained viable on toothbrushes bristles, in vivo, for 44 h.