If you have a cavity, does the tooth need to be extracted?

Tooth Decay: Only extensive decayed teeth need to be extracted if they can't be built up again. Early detection of decay will preserve tooth structure and protect the nerve inside preventing a root canal. Regular dental check ups, good brushing after meals and eating/drinking healthy will prevent tooth decay.

Unlikely: In most cases, teeth with cavities (decay) can be rebuilt to resemble a perfect tooth. Only in cases of severe decay, often extending below the gums, is extraction considered a treatment of choice, and often, even severely decayed teeth may be salvaged through a combination of root canal therapy, gum surgery (sometimes) and a crown (cap) to cover and protect the tooth.