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
A 40 year old male patient came for routine checkup. Intra-oral examination reveal multiple teeth restored with silver amalgam restoration. Linear coefficient of thermal expansion of this restoration is? 
Select and explain. 
A. 5 times greater than tooth structure, B. 2 times greater than tooth structure, C. 3 times greater than tooth structure, D. 2.5 times greater than tooth structure
D: 2.5 times greater than tooth structure
Answer: D: 2.5 times greater than tooth structure 
Explanation: Amalgam has a linear coefficient of thermal expansion that is 2.5 times greater than tooth structure, and it does not bond to tooth structure (unless an amalgam bonding agent is used). 
Sturdevant’s Art and Science of Operative Dentistry, Mosby, 4th Edition, Page No: 155