It is no secret that dentists are committed to saving teeth. This is why, when possible, we fill a cavity, rather than remove a tooth.
A cavity in a tooth can progress below the gumline to the point where restoration is virtually impossible without a procedure called crown lengthening. Crown lengthening is a routine surgical procedure which remodels the contour of the gumline. The procedure does not actually lengthen the crown, but rather lowers the gumline. When there is insufficient healthy tooth above the gumline to support a dental restoration, crown lengthening is very successful in exposing more of the tooth to access additional structure on which to build a crown.