The purpose of the current study was to evaluate the effect of functional monomers with phosphorus on bonding durability to titanium. Three metal conditioners (Alloy Primer, AP; Metal Link, ML; Eyesight Opaque Primer, EP) were assessed. The functional monomers for base metal are 10-methacryloyloxydecyl dihydrogenphosphate (MDP) for the AP, 6-methacryloxyhexyl phosphonoacetate (MHPA) for the ML, and methacrylatephosphate (MP) for the EP. Cast disk specimens made of high-purity titanium (T-Alloy H) were air-abraded with 70μm alumina, primed with three conditioners, and then bonded with an acrylic resin adhesive (Super-Bond C&B). Shear bond strengths were determined both before and after thermocycling (20, 000 cycles).
Before thermocycling, the shear bond strengths for the AP and ML groups were significantly higher than those for the EP and unprimed (defined as control) groups (p<0.05). The AP group exhibited significantly higher bond strength than the ML group after thermocycling (p<0.05). Significant difference was not found between the EP and the unprimed groups regardless of thermocycling application (p>0.05).