The black color of the knocked out incisor of a toddler may be due to the pulp necrosis of the incisor caused by the trauma, which needs to be treated with root canal treatment or extraction in time. 1. Root canal treatment: Trauma can lead to pulp necrosis, resulting in insufficient blood supply to the tooth, causing the pulp tissue to decompose and metabolites to be deposited on the tooth, which can lead to the phenomenon of blackened incisors in young children. In this case, you can go to the hospital to do root canal treatment to prevent the condition from deteriorating and control the inflammation and infection so as not to further infect the neighboring teeth. 2. Extraction treatment: If pulp necrosis occurs after the trauma, causing apical periodontitis that destroys the alveolar bone and involves the neighboring teeth or causes infection in the neighboring area, the tooth should be extracted after infection control in time to avoid affecting the eruption of permanent teeth. Young children with incisor injuries try to do an oral examination once a year before the teeth erupt, usually pay attention to oral hygiene, morning and evening or after meals to brush teeth. At the same time, parents are advised to bring their children to the hospital stomatology department in time, so as not to aggravate the condition due to untimely treatment.