I recently find the more time you use your toothbrush, the harder it becomes! I've asked some people somewhere else and was told that it was because of the plasticiser leaching…… One thousand people will have one thosands answers...
I use toothpaste everyday and I will clear my toothbrush by water directly, my toothbrush is of Bamboo charcoal.
I really want to know:
1) Why? Will it do bad effects on my teeth?
2) How to avoid this?