Deep dental caries can be treated with filling, root canal or tooth extraction. 1. If deep dental caries does not cause infection of the pulpal tissue, and is only a simple defect of the hard tissue of the tooth, you can go to the doctor for filling and restoration of dental caries, i.e., the decayed part of the tooth will be cleanly abraded and then restored by filling with dental specialty materials. 2. If deep dental caries causes pulp tissue infection and pulpitis, root canal treatment is necessary to clean up the infected and inflamed pulp tissue in order to effectively treat the above symptoms. 3. If tooth decay causes most of the tooth tissue to be missing and cannot be repaired by filling or root canal treatment, the affected tooth can only be extracted and the missing tooth can be restored (e.g., full crown prosthesis, implant prosthesis, etc.) at a later date.