Ferrari M, Cagidiaco M C, Breschi R
University of Siena, Istituto Policattedra di Discipline Odontostomatologiche, Italy.
J Prosthet Dent. 1988 Feb;59(2):160-5. doi: 10.1016/0022-3913(88)90008-x.
The data confirmed that etching produced a stronger bond than air abrasion of the metal.