Loose teeth with pus may be chronic apical periodontitis or periodontal abscess, requiring root canal treatment or periodontal sequence treatment. 1. Chronic apical periodontitis: Chronic apical periodontitis is often combined with an apical fistula. If left untreated, the accumulation of inflammation at the root tip will result in loosening of the tooth and repeated pus overflow from the fistula. Root canal treatment is needed to remove the inflamed pulp and infected dentin from the inside of the tooth, and then fill it, usually the looseness will be relieved and the pus will disappear. 2. Periodontal abscess: Periodontal disease will appear in the advanced stage of alveolar bone resorption and deep periodontal pockets, alveolar bone resorption can lead to loosening of the teeth, periodontal pockets pockets of bacterial accumulation in the pocket of inflammation will lead to abscess. Periodontal sequential treatment is needed for supragingival cleaning, subgingival scraping, periodontal surgery, etc. When the effect is not good, extraction is necessary. It is recommended to go to the regular hospital stomatology consultation, by the physician examination after a clear diagnosis and symptomatic treatment.