- Don't store your toothbrush in a case
- Rinse well after using
- Replace frequently
"Keeping a spare toothbrush in your bathroom can make it easy to begin using a new toothbrush as soon as you're ready to toss your old one!"
This article contains more-detailed information: https://yourdentalhealthresource.com/top-tips-for-storing-your-toothbrush-and-keeping-it-clean/