Whether a tooth that is half decayed should be extracted depends on the condition of the patient's tooth root. It is recommended that the patient first undergo a dental X-ray to ascertain whether the tooth root is intact. If the tooth root is relatively sound, generally, extraction is not necessary. The decayed material in the tooth can be removed, followed by a pulp capping procedure, and then filling. Due to the severity of the decay, it is advisable to wear a porcelain crown for protection. If the decay has affected the dental pulp causing pulpitis, root canal treatment should be performed before filling the tooth and protecting it with a porcelain crown. However, if the tooth root is severely damaged, considering tooth extraction might be necessary.