A large tooth that is rotten with only a little bit of empty shell left needs to be restored depending on the condition of the tooth, and may need to be restored after root canal treatment, crown lengthening, or even after extraction. 1. Post-endodontic restoration: If the remaining tooth tissue and root length of the large tooth are still long enough to be retained, then root canal treatment is required, followed by crown restoration or crown restoration. 2. Crown lengthening: If the length of the root of the large tooth is long enough, but there is not enough tooth tissue on the gums, crown lengthening can be performed, followed by root canal treatment and crown restoration. 3. Post-extraction restoration: If it cannot be retained, it can only be restored after extraction. It is recommended to go to the hospital in time and receive treatment under the doctor’s guidance.