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
How is the depth of curing and shade of the material related? 
Select and explain. 
A. Lighter shade requires more curing, B. Darker shade requires less curing, C. Lighter shade requires less curing, D. Both 1 and 2
C: Lighter shade requires less curing
Answer: C: Lighter shade requires less curing 
Explanation: Optical modifiers affect light transmission through a composite. Thus, darker shades and greater opacities have a decreased depth of light-curing ability and require either an increased exposure time or a thinner layer when cured. Studies have shown that for optimal polymerization, resins with darker shades and opacifiers should be placed in thinner layers.
Phillip’s 12th edition page 291