When a large tooth is broken and rotten, it is necessary to go to the hospital for a specialist examination and dental x-ray so that it can be determined whether the affected tooth needs to be extracted. In general, if the tooth defect reaches below the gum or bone, or if the tooth defect reaches below the root bifurcation, and the tooth looseness is more than three degrees, the affected tooth can not be retained and needs to be extracted for later restoration treatment. If the tooth is not damaged to the above extent, the affected tooth can be retained and its chewing function can be restored through effective endodontic treatment and esthetic restoration.