Don’t overdo the peroxide use, as it is an oxidizer. 8. Dental Care Some major brand name toothpaste products contain hydrogen peroxide, but you can use your own if your toothpaste doesn’t have it. After brushing your teeth, rinse with a capful of peroxide or mix a 50-50 water-and-peroxide solution for rinsing. (Always use the three percent peroxide for home and medical purposes.). You also can rinse toothbrushes, dentures, and dental retainers in a 50-50 water-peroxide solution to remove germs.