Table 1. Groups, material and application protocols used in the present experiment.

Group	n	Material	Manufacturer	Composition	Lot #	Application	Aging
1	15	-	-	-	-	-	No
2	15	Icon	DMG (Hamburg, Germany)	Icon-Etch: hydrochloric acid salicylic pyrogenic acid.	632178	Applied for 120 s.	No
				Icon-Dry: 99% ethanol.		Applied for 30 s with air drying.
3	15			Icon-Infiltrant: resin matrix based on methacrylates, primers and additives.		Applied for 180 s, reapplied for 60 s, cured for 40 s.	Yes
4	15	Clinpro XT Varnish	3 M Unitek (Landsberg, Germany)	Silanized glass powder, silica treated with silicon, methacrylate, 2-hydroxyethyl, water, BIS-GMA, copolymer of acrylic acid and itaconic.	12248	35% phosphoric acid for 20 s, washing and air drying, mixing the components, application and curing for 20 s.	No
5	15						Yes