Purpose: The objective was to determine the level of contamination of toothbrushes by mutans streptococci using microbiological identification, to access the bacterial contamination using scanning electron microscopy (SEM) and to evaluate the efficacy of two toothbrush disinfectants.
Methods: Nineteen children used their toothbrushes once a day, for five consecutive days. The toothbrushes were then immersed into disinfectant solutions for 20 h: Group I--0.12% chlorhexidine gluconate; Group II--1% sodium hypochlorite; Group III--sterile tap water. They were then placed into test tubes containing CaSa B, for 3 to 4 days at 37 degrees C. The number of MS cfu was counted and the toothbrushes were submitted to SEM analysis.
Results: There was no bacterial growth in Groups I and II; Group III showed MS growth (range, 21 to 120 cfu). Scanning electron microscopy showed biofilm formation on toothbrush bristles.
Conclusion: Immersion in 0.12% chlorhexidine gluconate and 1% sodium hypochlorite are efficient methods for toothbrush disinfection.