Efficacy of two mouth rinse sprays in inhibiting Streptococcus mutans growth on toothbrush bristles

To compare the efficacy of two types of mouth rinse sprays (Periogard and Plax) in inhibiting the growth of Streptococcus mutans (S. mutans) on toothbrush bristles used by children. An experimental comparative study was performed. The sample included 60 children aged 6–8 years with high caries index. Children were divided randomly into 3 groups (20 each) according to materials applied on toothbrush. Each group was further subdivided into 2 subgroups A and B (10 each) according to the laboratory standards for processing microbiological specimens. Each toothbrush was placed in phosphate buffered saline, vortexed then serially diluted. Mitis salivarius bacitracin (MSB) agar plates were inoculated and incubated for 48 h. S. mutans colonies were identified by morphology, gram stain and biochemical tests. Statistically, significant difference was observed between the three groups either when toothbrushes were processed immediately or when processed after 24 h. Group I showed highest bacterial count followed by group III whereas group II showed least bacterial count. Bacterial counts were significantly decreased by time in group I and group III while in group II no significant decrease as both subgroups showed very low bacterial count. Although both mouth rinses were effective against S. mutans toothbrush contamination, chlorhexidine gluconate proved to be better.