Comparison of Bacterial Contamination in Bristles of Charcoal Toothbrushes versus Non-Charcoal Toothbrushes: A Randomized Clinical Trial

Abstract

Background: Toothbrush may serve as a reservoir for harbouring diverse colonies of microorganisms. For protection against toothbrush mediated oral contamination, toothbrushes with charcoal infused bristles are also available in the market. They are regarded as antibacterial in their role but limited evidence is available on their performance over an extended period of use. This study compares bacterial contamination in the bristles of charcoal versus non-charcoal toothbrushes after two weeks of routine use.

Methods: A randomized clinical trial was carried out for comparing bacterial colonization of charcoal and non-charcoal toothbrushes in n=230 dental students and house officers after two weeks of routine brushing. Both groups received identical toothpaste and standardized brushing instructions and used their assigned brush for two weeks. Bristles from their respective toothbrushes were then aseptically excised, suspended in nutrient broth, and cultured on blood agar for 24–48 hours under standard laboratory conditions. Colony-forming units (CFUs) were counted, and the two groups were compared using an independent-samples t-test, with p≤0.05 taken as significant.

Results: Charcoal bristles carried a mean of 5.1 CFUs compared with 15.0 CFUs for non-charcoal bristles, a highly significant difference (p=0.001).

Conclusions: After two weeks of daily use, charcoal-infused bristles carried substantially low bacterial load as compared to conventional non charcoal toothbrushes. Therefore charcoal infused toothbrushes resist bacterial ccolonization supporting their potential role in reducing toothbrush-related contamination.