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': 'Gold restoration cemented with zinc polycarboxylate usually fractures at which interface? \nSelect and explain. \nA. Cement-prosthesis, B. Cement itself, C. Tooth structure - cement, D. Prosthesis failure', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Zinc polycarboxylate has ability to bond chemically with tooth structure so less chance of failure at tooth cement inteface\nIn case of gold restorations usually adhesive failure occurs at the interface b/w gold & cement\nIn case of non-precious metals usually cohesive failure occurs b/w cement layer itself.', 'role': 'assistant'}]