The teeth next to the incisors are lateral incisors, and a cavity in a lateral incisor may be due to dental caries or congenital malformation of the tooth, which corresponds to the need for resin filling after decay removal or filling after root canal treatment. 1. Tooth decay: when the decayed lateral incisor forms a deep cavity and has not reached the pulp cavity, it needs to be filled with resin after removing the decayed tooth tissue as soon as possible by using specialized instruments, and if the decay reaches the pulp cavity, it needs to be filled only after root canal treatment. 2. Congenital malformation of teeth: lateral incisors in the lingual part of the tongue is prone to malformation of the lingual fossa, teeth in the teeth, with a probe can be explored to the depth of the hole, did not reach the pulp cavity after the preparation of the cavity type of resin filling caused by pulpal infections, need to be filled after root canal treatment. Teeth next to the incisors have holes in the teeth are recommended to the hospital in a timely manner to deal with, to avoid causing pulpal infection tooth pain.