Table 1. Composite materials used in the study.

Composite Resin	Manufacturer	Lot	Shade
SimpliShade Universal	Kerr Corporation, Orange, CA, USA	8086055	DK
Transcend	Ultradent Products Inc., South Jordan, UT, USA	RN776	UB
Omnichroma	Tokuyama Dental Corporation, Tokyo, Japan	042E41	Universal
Filtek Universal Restorative	3M, St Paul, MN, USA	NE15442	A2