Table 1: Distribution of the groups according to treatment received before bonding and luting agent tested.

Type	Group	N	Luting Agent	Manufacturer
Control	G1	10	RelyX ARC	3M, ESPE, St Paul, MN, USA
(Unbleached teeth – immersed in distilled water)	G2	10	RelyX Unicem	3M, ESPE, St Paul, MN, USA
Experimental	G3	10	RelyX ARC	3M, ESPE, St Paul, MN, USA
“Walking bleach” (35% hydrogen peroxide)	G4	10	RelyX Unicem	3M, ESPE, St Paul, MN, USA