Because this is where the entire restoration is finalized
You can achieve perfect isolation. Etch correctly. Follow the bonding protocol. Place composite in controlled increments. Build the contact. Create beautiful anatomy. But until the material has received adequate curing, the restoration is not finished.
Curing is not a technical formality at the end of the procedure. It is one of the steps that determines whether your work stays the way you made it. That makes the curing light a strange place to accept uncertainty.





















