Effect of single-liquid acidic primers on bonding of a composite luting agent joined to a prefabricated alumina coping material.

PURPOSE The aim of this study was to assess the effect of acidic primers on adhesive bonding to prefabricated alumina material designed for fixed restorations. METHODS High-purity alumina disks (Procera AllCeram) were primed with one of the following materials: Acryl Bond, All Bond II Primer B, Alloy Primer, Estenia Opaque Primer, M.L. Primer, MR. Bond, and Super- Bond Liquid. The specimens were bonded with a dualpolymerizing luting composite (Variolink II). Unprimed specimen was prepared as the control. Bond strengths were determined both before and after thermocycling. RESULTS Average bond strength before thermocycling ranged from 12.0 to 39.1 MPa, whereas average bond strength after thermocycling varied from 0.0 to 26.9 MPa. The statistically highest post-thermocycling bond strength was obtained with the use of the Alloy Primer, Estenia Opaque Primer, and M.L. Primer agents. CONCLUSION It can be concluded that the use of either the Estenia or Alloy Primer material, which contain 10- methacryloyloxydecyl dihydrogen phosphate (MDP), or the M.L. Primer, which contains 6-methacryloyloxyhexyl phosphonoacetate (6-MHPA), is recommended for bonding the Procera alumina copings with the Variolink II composite.