Doramad radioactive toothpaste was produced until 1945 in Germany. It contained small amounts of Thorium. Here’s what they thought about radiation back then:

Its radioactivity increases the defenses of teeth and gums. The cells are loaded with new life energy, the bacteria are hindered in their destroying effect. This explains the excellent prophylaxis and healing process with gingival diseases. It gently polishes the dental enamel so it turns white and shiny. Prevents dental calculus. Wonderful lather and a new, pleasant, mild and refreshing taste. Can be applied sparingly.

The following pictures are from a Doramad brochure: