One third of the large tooth is left, whether it can be restored depends on the remaining dental tissues, if the dental tissues are relatively healthy, generally can be restored. 1. With one-third of the tooth remaining, the tooth is now severely damaged, the pulp is usually exposed and there may be significant pain and discomfort, and the pulp is usually necrotic. If the remaining tissue is unhealthy, and the root of the tooth is significantly loosened, it is usually not possible to restore the tooth. 2. However, if the remaining tooth tissue is relatively healthy and the root is not seriously loosened, restorative treatment is often possible, mainly root canal treatment, to avoid later stimulation of the nerve causing pain, and then crown restorative treatment. One-third of the large teeth left should be timely to the hospital stomatology department, with the doctor to take treatment, to avoid the damage continues to aggravate.