It is common to knock out a small incisor in tooth trauma, which belongs to crown fracture. The outermost layer of teeth is enamel layer and the inner layer is dentin layer. If the defect is only in the enamel layer of the tooth, resin repair can be considered to restore the shape of the tooth. If the defect is large and affects dentin, indirect pulp capping is needed. Calcium hydroxide is often used to cover the pulp indirectly, and then resin is used to repair it.

If the defect spreads to the pulp and the pulp is exposed, the corresponding pulp treatment should be considered, including direct pulp capping treatment or vital pulp cutting treatment, and the tooth shape should be further restored after the pulp is preserved. If the defect is serious, the repair effect is not ideal, the material repaired by resin is easy to fall off, and the porcelain crown can also be repaired. Before porcelain crown restoration, pulp improvement is generally needed, which usually includes root canal treatment.