Can tooth cavities treated or prevented by oneself after started?

Sorry...No. Once a cavity starts, there's no way to reverse it by yourself. Nearly always, the infected/softened part of the tooth has to be removed, the remaining tooth cleaned & conditioned, & the missing part of the tooth replaced with a modern dental material. In very, very small cavities, newer techniques allow us to repair it without removing any tooth structure. Get it fixed while it's small and easy.
No, if started. You can slow it down with Fluoride and brushing/flossing but you will not be able to clean it totally out with out a dentist's help. You can prevent by brushing and flossing and check ups. Catch them early and less pain or prob.

Related Questions

What can be done to prevent tooth cavities?

Floss, brush, dentis. Besides flossing , brushing ad seeing your dentist every 4 to 6 month, make sure your tooth paste has fluoride. Diet is also important . Avoid drinks that have hidden sugar like gatterade and various fruite juice or soft drinks, and sugar. Read more...
Make sure. You are brushing at least two times a day for at least 2 minutes each time - mechanical toothbrush preferable. Also use a waterpik. Avoid sugary sodas, candies, foods, juices, energy drinks. Everything in moderation. Sometimes you can do everything possible and still develop cavities. Sadly that's life! make sure you visit your dentist every six months as well. Read more...