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': 'Which generation of flowable composites can be used as restorative material? \nSelect and explain. \nA. 1st generation, B. 2nd generation, C. Both, D. None', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Flowable composite\nLow filler content, lower viscosity\n1st generation:\n\nInferior mechanical properties\nOnly used as P&F sealant\xa0\n1st layer of composite on tooth surface\n\n2nd generation:\n\nBetter mechanical properties\nCan be used as restorative material\nEntire restoration', 'role': 'assistant'}]