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': 'Mode of failure during dislodgement of prosthesis cemented with zinc polycarboxylate cement is usually seen at the: \nSelect and explain. \nA. Cement tooth interface, B. Cement prosthesis interface, C. Cleavage through the cement layer, D. Fracture of tooth or prosthesis', 'role': 'user'}, {'content': 'Answer: B \nExplanation: LUTING INTERFACE\n\nLuting cements are designed to ﬁll the microscopic gaps between a prosthesis and a prepared tooth.\xa0\nEach surface is microscopically rough, having peaks and valleys, and only point contacts are made by\xa0the peaks.\xa0\nThe areas that are not in contact must be ﬁlled by the cement to prevent oral ﬂuid ﬂow and\xa0bacterial invasion.\xa0\nOne can seal the space by placing a soft adhesive between the two surfaces, which can conform under pressure to the roughened surface features.\n\nRef: Phillips Ed 12th P: 311', 'role': 'assistant'}]