Purpose: The purpose of vitro study was to assessment of the bacterial contamination on daily twice-used toothbrushes in different conditions after 1-month and 3 months.
Materials and methods: Forty children aged between 6 and 12 years were selected for this study. Toothbrushes and toothpaste were distributed among those children. Among those children, 20 children brushed their teeth for 1-month and 20 brushed their teeth for 3 months twice a day. Among those, 10 were kept in same brush box with a family member and 10 were kept in separate brush box after the use. Toothbrush from every child was recollected to investigate the contamination of microorganisms. Head of the toothbrushes transferred to a tube containing 10 ml of tryptone soy broth. This was followed by vortex mixing for 1 min to dislodge suspected adherent bacteria. The bacterial suspension was serially diluted to obtain dilution factors of up to 10(-3). 1 ml each of the dilution factors was obtained using a sterile pipette and plated on plate count agar. Petri dishes containing agar media were incubated and examined using a compound microscope.
Results: There was high mean difference between 1-month and 3 months, twice a day used toothbrush those kept with family members and those kept separate.
Conclusions: Toothbrush should keep in a separate box. Moreover, toothbrush should to be change after 3-4 weeks.
Keywords: General health; microorganisms; oral diseases; oral hygiene.