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': 'Investment material used for high fusing base metal partial dentures \nSelect and explain. \nA. Gypsum bonded., B. Phosphate bonded., C. Silica bonded., D. All of the above.', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Silica bonded\n• Silica is the binder which may be derived from ethyl silicate or silica gel\n• Used for high fusing base metal partial denture alloys\n• In addition to setting shrinkage "green shrinkage" occurs due to loss of alcohol and water from the gel.\n• The investment can be heated upto 1200°C', 'role': 'assistant'}]