Which generation of flowable composites can be used as restorative material?: (A) 1st generation, (B) 2nd generation, (C) Both, (D) None
Answer is B. Flowable composite
Low filler content, lower viscosity
1st generation:

Inferior mechanical properties
Only used as P&F sealant 
1st layer of composite on tooth surface

2nd generation:

Better mechanical properties
Can be used as restorative material
Entire restoration