Table 2.

Materials used in the study.

Materials	Manufacturer	Lot no.	Contents	Wt%
Transbond XT	3M Unitek (Monrovia, CA, USA)	N568393	Silane treated quartz	70–80
			Bis-GMA	10–20
			EBPADMA	5–10
			Silane treated silica	<2
Etching gel	3M Unitek (Monrovia, CA, USA)	576331	Water	55–65∗
			Phosphoric acid	30–40∗
			Amorphous silica	5–10∗

Bis-GMA indicates bisphenol-A-diglycidyl ether dimethacrylate and EBPADMA bisphenol-A-bis(2-hydroxyethyl ether) dimethacrylate.

^∗The specific chemical identity and/or exact percentage (concentration) of this composition has been withheld as a trade secret.