1. Guba CJ, Cochran MA, Swartz ML (1994) The effects of varied etching time and etching solution viscosity on bond strength and enamel morphology. Oper Dent 19:146–153
2. Fanchi M, Breschi L (1995) Effects of acid-etching solutions on human enamel and dentin. Quintessence Int 26:431–435
3. EJ S Jr, Perdigão J, Heymann HO (1995) Bonding to enamel and dentin: a brief history and state of the art, 1995. Quintessence Int 26:95–110
4. Lopes GC, Thys DG, Klaus P, Oliveira GM, Widmer N (2007) Enamel acid etching: a review. Compend Contin Educ Dent 28:18–24
5. Pahlavan A, Dennison JB, Charbeneau GT (1976) Penetration of restorative resins into acid-etched human enamel. J Amer Dent Assoc 93:1170–1176