5Gorelick L. Bonding metal brackets with self-polymerizing sealant-composite: a 12-month assessment. Am J Orthod.1977;71(5) :542.
6Nordenvall KL, Brannstromm M, Malmgren O. Etching of deciduous teeth and young and old premenent teeth. A comparison between 15 and 60 seconds of etching. Am J Orthod. 1980;78(1) :99.
7Brannstrom M,Malmgren O,Nordenvall KJ. Etching young permanent teeth with an acid gel. Am J Orthod. 1982; 82(5) :379.
8Barkmeier w, Gwinnett J, Sheeffer S. Effects of enamel etching time on bond strength and morphology. J Clin Orthod. 1985;19(1):36.
9Kinch AP, Taylor H, Warltier R. A clinical trial comparing the failure rates of directly bonded brackets using etch times of 15 or 60 seconds. Am J Orthod Dentofacial Orthop. 1988;94(6) :476.
10Carstensen W. Clinical effects of reduction of acid concentration on direct bonding of bracket. Angle Orthod. 1993; 63(3) :221.
