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': 'The best bio-compatible dental casting alloy is: \nSelect and explain. \nA. Co-Cr, B. Ni-Cr, C. Titanium alloy, D. Gold', 'role': 'user'}, {'content': 'Answer: C \nExplanation: TITANIUM AND TITANIUM ALLOYS\nIn vitro evaluation of titanium biocompatibility, percentage attachment efficiency, and proliferation of human fetal fibroblasts and human gingival fibroblasts reveals that a surface layer of titanium oxide (Ti 2 O 3 ) has the ability to coexist with living tissues and organisms. Based on these\xa0studies one can conclude that titanium is relatively nontoxic, noninjurious, and not physiologically reactive. Titanium has a light weight, high\xa0 strength, and excellent durability when exposed to chemical agents. However, it is susceptible to attack by acidic fluoride products.\nPhillips 12 ed page 126', 'role': 'assistant'}]