Table 1.

Adhesive system (batch number), composition, manufacturer and application technique according to manufacturer’s instructions

Adhesive system (batch number)	Compositions	Manufacturer	Application Technique
Adper Single Bond 2 (479674)	1. Etchant: 35% phosphoric acid (GelEtch, SCI-PHARM, America)	3M ESPE, St. Paul, MN	1. Apply etchant for 15 s
	2. Adhesive: Bis-GMA, HEMA, dimethacrylates, ethanol, water, photoinitiator system, methacrylate functional copolymer of polyacrylic and polyitaconic acids, 10% by weight of 5 nm-diameter spherical silica nanopaticles		2. Rinse for 15 s
			3. Blot excess water using a cotton pellet without air-drying
			4. Apply one coat of adhesive for 10 s with gentle agitation
			5. Gently air-dry (10 s at 20 cm)
			6. Apply one coat of adhesive for 10 s with gentle agitation
			7. Gently air-dry (10 s at 20 cm)
			8. Light curing for 10 s

Bis-GMA: bisphenol-A-diglycidylmethacrylate; HEMA: hydroxyethylmethacrylate.