Purposes: The purposes of this study were to, determine the level of contamination by mutans streptococci on the toothbrushes of children using microbial identification and evaluate the efficacy of 0.12% chlorhexidine spray vs chlorhexidine mouthwash as toothbrush disinfectants.
Methods: Seventy-one 7-year-old children were randomly selected for this study. The children were divided into 3 groups, according to the number of cfu/ml of mutans streptococci in the samples: (1) low caries risk (0-21 cfu/ml); (2) medium caries risk (21-100 cfu/ml); and (3) high caries risk (>100 cfu/ml). According to this evaluation, 24 children from the high dental caries risk group were selected to participate in this study. After oral hygiene instruction, the children participated in a supervised daily tooth-brushing for 5 consecutive days. At the end of these days, all toothbrushes were collected. The toothbrushes were divided into 3 groups randomly: (1) group 1 (chlorhexidine [CHX] mouthwash)--toothbrushes were immersed individually in test tubes containing 10 ml of 0.12% CHX gluconate and 0.15% benzidamin; (2) group 2 (CHX spray)--toothbrushes were sprayed with the solutions, including 0.12% chlorhexidine gluconate and 0.15% benzidamin, onto the bristles twice; (3) group 3 (sterile saline)--toothbrushes were immersed individually in test tubes containing 10 ml sterile saline as a control. After the microbiologic procedures, the number of mutans streptococci colonies were counted and statistically evaluated. The toothbrush bristles were carefully inspected, and the biofilm formation was evaluated under aseptic conditions with a stereoscopic microscope.
Results: There was no statistically significant difference between the CHX mouthwash and spray groups (P >.05), but a statistically significant difference was observed between the control group and the other test groups (P <.05).
Conclusion: All toothbrushes immersed in sterile saline showed high mutans streptococci counts and biofilm formation. There was no statistically significant difference between the chlorhexidine mouthwash and spray groups, and both approaches had the ability to disinfect the toothbrushes if maintained for 2 hours.