A rotten tooth with a hole that smells bad means that there is a cavity in the tooth. Depending on the depth of the cavity, it needs to be filled with resin or filled after root canal treatment. 1. Resin filling. When a tooth has a cavity, food debris will be embedded in the cavity, and the odor will appear under the action of bacteria. If the cavity has not penetrated through the pulp cavity, it is necessary to use special instruments to grind away the decayed tooth tissues, and then use resin to fill the cavity after cleaning it. 2. Filling after root canal treatment. Tooth caries, if through the pulp cavity will cause pulpitis, periapical inflammation, in which the liquid leakage can also appear bad smell, generally need root canal treatment to eliminate inflammation before resin filling. It is recommended to go to the hospital as soon as possible to avoid affecting oral health.