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': 'Causes of postoperative sensitivity with amalgam restorations include all of the following except _____. \nSelect and explain. \nA. Lack of adequate condensation, especially lateral condensation in the proximal boxes., B. Voids., C. Extension onto the root surface., D. Lack of dentinal sealing.', 'role': 'user'}, {'content': 'Answer: C \nExplanation: The primary causes of postoperative sensitivity for amalgam restorations are voids (especially at the margins), poor condensation (that may result in a void), or inadequate dentinal sealing. Extension onto the root surface does not necessarily result in increased sensitivity.', 'role': 'assistant'}]