Is "roughening" a tooth with a slow-speed drill necessary for side bondings, in addition to using acid etching gel?

The dentist who originally put in my side bondings said no drilling was necessary and that acid etiching was sufficient. After about one year, one of them came out and I had it replaced by a new dentist. The new dentist insisted that "roughening" the tooth surface with a drill was necessary in addition to acid etching (this is on the actual tooth surface, as I have gum recession that exposes the tooth below the enamel). There is still ~4mm tooth structure left--is this sustainable? Opinions?