The innermost tooth may be a wisdom tooth or other molar, if it is a wisdom tooth, it is recommended to be extracted, and if the other molar is able to be treated with root canal treatment, it should be treated with root canal treatment first. 1. Wisdom teeth: The innermost tooth may be a wisdom tooth. Since wisdom teeth are at the most distal end of the dental arch, they often cannot be cleaned in place and cause distal or proximal food blockage, or are congenitally impeded, resulting in dental caries, and it is generally recommended that wisdom teeth be extracted as early as possible. 2. Other molar teeth: If the wisdom tooth is congenitally missing, it may be the second molar tooth. According to the degree of tooth decay, if the tooth is still able to do root canal treatment, it will be done after root canal treatment and pile core crown repair; if the tooth has been mostly decayed and cannot be treated, it is recommended to extract it and then repair it with denture. It is recommended to go to the hospital for examination and treatment in time to avoid the deepening of caries affecting oral health.