If caries has reached the level of residual crowns or roots, it means that the condition has been very serious, usually can not be retained, in the mouth will cause the accumulation of bacteria, resulting in the tissue itself is difficult to heal, this situation is recommended that the patient to the hospital in a timely manner, and actively carry out the extraction of treatment. In some older patients, the residual roots can be retained to form overdentures. Usually, when the roots of carious teeth are rotten, it is recommended that the patient be extracted, so as not to cause other unnecessary infections or lead to long-term chronic inflammatory state.