Microbiological contamination of toothbrushes and identification of a decontamination protocol using chlorhexidine spray

Abstract

Purpose: This study evaluated the rate of microbial contamination of toothbrushes used by students and established a protocol for the spraying of 0.12% chlorhexidine to decrease the bacterial presence on the bristles of the brushes. Methods: We performed cultures on selective and nonselective media from toothbrushes used by Dentistry students from State University of West Paraná (Unioeste / PR) to identify and quantify the number of total and specific microorganisms. For the chlorhexidine test, a crossover and double-blind study was conducted, with a random selection of volunteers. Each experimental phase consisted of fourteen days of brushing and an interval of seven days between treatments. For the test, thirty volunteers, divided into three groups of 10, using new toothbrushes, sprayed with either water or 0.12% chlorhexidine gluconate at different intervals (once or three times daily) after brushing. For statistical analysis, we used main effects ANOVA, and a P-value < 0.05 was considered significant. Results: There was microbial growth on 91% of the used toothbrushes, with 81.3% showing growth of Streptococcus. In 56.3% of the brushes, Staphylococcus and Enterobacteriaceae developed. The use of the chlorhexidine spray only three times per day was significantly more effective than water. Conclusion: Even in a group that knows the ideal conditions for the storage of toothbrushes, much microbial contamination still exists on the toothbrushes. A lower bacterial load can be obtained from the simple and inexpensive act of spraying chlorhexidine on the toothbrush after every brushing of the day.