If the tooth has rotted a big part of the tooth and smells especially bad, usually endodontitis has occurred, and according to the degree of rotting of the tooth, you can choose to have a crown restoration after root canal treatment or extract the tooth. 1. Root canal treatment and crown restoration: after removing the rotten tissues of the tooth, the tooth still has value, it is best to perform root canal treatment on the tooth, and then perform crown restoration after two weeks if the tooth does not show pain. 2. Tooth extraction: after removing the rotten tooth tissue, the tooth has no retention value, in this case, the tooth needs to be extracted, and then choose denture restoration or dental implant restoration in the later stage. If the tooth is half rotten, go to the hospital in time, take a tooth root film to determine the root condition, and then determine the best treatment plan according to the results of the examination.