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': 'pH of polycarboxylate liquid is: \nSelect and explain. \nA. 5, B. 7, C. 8, D. 1.7', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Biocompatibility\nPulpal response is classified as mild. Despite the initial acidic nature of polycarboxylate cement, the pH of the liquid is 1.0-1.07 and that of freshly mixed cement is 3.0-4.0. After 24 hours, pH of the cement is 5.0-6.0.\nThey are less irritant than zinc phosphate cement because:\n\nThe liquid is rapidly neutralized by the powder. The pH of polycarboxylate cement rises more rapidly than that of zinc phosphate.\nPenetration of polyacrylic acid into the dentinal tubules is less because of its higher molecular weight and larger size. The histological reactions are similar to zinc oxide eugenol cements but more reparative dentine is observed with polycarboxylate.\n\nRef: Manappalil P;97', 'role': 'assistant'}]