The Adult thoothbrush is made from bamboo and the bristles is mady from bamboo charocal. (Biopolymer completerly without plastic)
The child have bristle made of nylon. (biogradable)
The bamboo stick is heated (darker color) to create an stabile and lasting tootbrush.
Keep it dry between uses. Dentist recommend to replace tootbrush 2-3 month
It last longer if you keep it well.