Composites usually do not need pulp thermal protection below it because they have:
Composites usually donot need liners and bases for thermal protection as they are poor conductors of heat and have low thermal conductivity. They may need liners for pulp capping and also to reduce effects of polymerization shrinkage but not for thermal protection.
Reference- Sturdevant 6th ed
High Linear coefficient of thermal expansion
High density
Low thermal conductivity
All of the above