Abstract: Orthodontic appliances having improved bonding characteristics and methods of making such orthodontic appliances are disclosed. The appliances have a metal bonding base and tooth contact surface. A primary mechanical interlock retention surface is applied to the tooth contact surfaces. The primary retention surface may be 1) a mesh, 2) a layer of metallic or non-metallic particles, or 3) grooves, including undercuts, formed in the tooth contact surface. The appliances may also include a secondary mechanical bond strength enhancement treatment. Suitable secondary enhancement treatments include 1) surface toughening, 2) particles applied to the primary retention surface, and 3) a chemically activatable material, such as SiO.sub.2, deposited on the primary retention surface. Chemical activation may also be used to activate the chemically activatable material, such as silanation of SiO.sub.2.