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': 'Laser welding \nSelect and explain. \nA. Involves high heat generation, B. Can be done with pure Titanium, C. Is not used in dentistry, D. Can be done with pure gold', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Laser welding of titanium has facilitated repair of titanium frameworks because of the low thermal conductivity of titanium and localized heating during laser welding.\nLaser welding in an argon gas atmosphere is a method of choice for joining titanium components of dental prostheses, because the coherent, high-intensity laser pulse of light can be focused in a small region and melt the substrate without extensive microstructural damage to the surrounding areas.\nRef: Phillip’s 12th edition page 386, 392', 'role': 'assistant'}]