This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Dental
[{'content': 'An avulsed tooth is not replanted for more 60 minutes then it should be kept in: \nSelect and explain. \nA. Citric acid for 5 minutes, B. Doxycycline for 5 minutes, C. 2% SnF2 for 5 minutes, D. All of the above', 'role': 'user'}, {'content': 'Answer: D \nExplanation: If the tooth was out over two hours, the periodontal ligament is dead, and should be removed, along with the pulp. The goal of delayed replantation is to promote the alveolar bone growth to encapsulate the tooth. Eventual outcome is ankylosis.\nLocal anesthesia will probably be needed before reimplanting as above.\nThe tooth should be soaked for 30 minutes in 5 percent sodium hypochlorite and 5 minutes each in saturated citric acid, 1-2% stannous fluoride and 5 percent doxycycline before reimplanting.\nEndodontic treatment is done either before replantation or 7 to 10 days after replantation.\nReplant the tooth gently with firm finger pressure. Ask the patient to bite down firmly on a piece of gauze to help stabilize the tooth.\nVerify the position of replanted tooth on radiograph.\nStabilize it for 1-2\xa0weeks.\nAdminister systemic antibiotics.', 'role': 'assistant'}]