The tooth floating up may be due to the tooth suffering from periapical inflammation, most of the cases are due to the decay is not treated in time, the infection spreads to the tooth nerve causing pulpitis, and the pulp inflammation further spreads to the periapical tissue, causing periapical inflammation. The inflammation causes inflammation, swelling, pus, and bone resorption of the periapical bone, which in turn causes the inability to bite, and even paroxysmal severe throbbing pain, thus causing the patient to have the feeling of elongation and floating of the tooth. During the acute inflammatory painful phase of periapical periodontitis, oral anti-inflammatory drugs such as cephalosporin, erythromycin, amoxicillin, and metronidazole can be taken to reduce inflammation. The treatment for periapical periodontitis is root canal therapy, and apical inflammation can only be gradually eliminated after the infected tooth and pulp tissue are removed using root canal therapy. Severe periodontitis is caused by serious destruction of periodontal bone tissue resorption, resulting in root exposure, tooth loosening, and a feeling of floating teeth.