In case of tooth decay, if it is a general hospital, if it is a general department, you can directly register with the Department of Stomatology. If there are further subspecialties or in a dental hospital, you can register with the Department of Endodontics. The treatment of tooth decay is also called filling. If you are in a clinic, generally you will not have to divide it into so many details, and you can just see the stomatology department directly. If the tooth decay is shallow, it can be filled up after grinding the decayed tooth at that time. If the tooth decay is very deep, even to the nerve, root canal treatment is needed, which may take several visits.