Microbes survive in a wide range of habitats, like toothbrush bristles regardless of where they are stored after being unsterilized. The most common technique for maintaining good oral hygiene is tooth brushing. By scraping plaque and other soft debris from the teeth, tooth brushes become contaminated with bacteria, blood, saliva and oral debris. Toothbrushes are a place for the transfer of microbes, retention and growth. There could be a source of infection with these infected toothbrushes. This article discusses the oral microbial flora and how the contaminated toothbrush affects oral hygiene.