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': 'Which of the following medicaments is indicated to obturate the canals of a primary tooth in which a pulpectomy was performed? \nSelect and explain. \nA. Gutta-percha, B. Calcium hydroxide, C. Zinc oxide-eugenol, D. Calcium hydroxide-CMCP paste', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Zinc Oxide Eugenol\xa0\n\nMost commonly used.\nBonastre (1837) discovered zinc oxide eugenol (ZOE)\xa0and it was subsequently used in dentistry by Chisholm\xa0(1876).\xa0\nZinc oxide eugenol paste, the first root canal filling material\xa0to be recommended for primary teeth, as described by\xa0Sweet in 1930.\xa0\nZinc oxide eugenol is said to have anti-inflammatory and\xa0analgesic properties.\xa0\nIts limitations are slow resorption, irritation to the\xa0periapical tissues, necrosis of bone and cementum and\xa0alters the path of erupting teeth.\xa0\nWhen ZOE mixture is used, thin mixture is used to coat\xa0the walls of the canal, followed by a thick mixture that can\xa0be manually condensed into the lumen of the canal.\xa0\nBarr et al. showed 82.3 percent clinical success rate,\xa0Gould showed 86.1 percent, Coll et al. showed 86.1\xa0percent clinical success rate.\xa0\nBarcelos et al. showed 85 percent of clinical success with\xa0ZOE but the overfilling was evident even after evaluation\xa0period.\n\nReference: Pediatric Dentistry by Nikhil Marwah 3rd ed, page\xa0 no 672', 'role': 'assistant'}]