Low-environmental-impact Bamboo Toothbrushes Demonstrate Comparable Hygienic Condition to That of Plastic and Biomass Plastic Toothbrushes after Use and Storage

Abstract

Brushing with a toothbrush is effective for removing oral biofilms. However, tooth brushes can be a source of infectious diseases after use. Recently, the environmental impacts of plastics, such as marine pollution, have become an issue. This includes the disposal of plastic toothbrushes. Consequently, bamboo toothbrushes, with a low envi ronmental impact, have become widely-used as alternatives. Although there are many reports on the hygiene of plastic toothbrushes after use, there are few reports on bam boo toothbrushes. Thus, we compared the hygiene of bamboo toothbrushes with those of plastic and biomass plastic toothbrushes after use and storage. Three types of tooth brushes were immersed in bacterial cultures and washed, and the number of bacteria on the toothbrushes after 12 and 24 h of storage was examined. The number of bacteria on the bamboo toothbrushes immediately after immersion was significantly higher than on the other two types, but this number was 95–99％ lower after 12–24 h of storage. No differences were observed for different bacterial species（Actinomyces oris and Strep tococcus mutans）or different storage conditions（wet and dry）. However, pre-wetting before immersion significantly reduced the number of bacteria on the bamboo tooth brushes.