Dipentaerythritol Penta-Acrylate Phosphate as an Alternative Phosphate Ester Monomer for Bonding Methacrylates to Zirconia

Purpose：The study tests dipentaerythritol penta-acrylate phosphate as an alternative to MDP for bonding methacrylate resins to zirconia and investigates the interfacial chemistry.

System and methods：Experimental primers containing 5, 10, 15, 20 or 30 wt% PENTA in acetone were compared with PENTA-free and MDP-containing controls using shear bond strength. ICP-MS, XPS and FTIR examined phosphorus and chemical bonding on the zirconia surface.

Key findings and mechanism：Primers with 5, 10, 15, 20 and 30 wt% PENTA were compared with PENTA-free and MDP-containing controls. The 15% and 20% groups showed significantly higher shear bond strength. ICP-MS showed increasing surface phosphorus with concentration, while XPS and FTIR supported formation of Zr-O-P bonds. Bonding did not increase beyond the optimum concentration. The phosphate group reacts with hydroxyls or zirconium sites on the oxide surface, while the acrylate end participates in resin polymerization. The molecule therefore bridges the inorganic surface and organic network in a representative molecular-rivet mechanism.

Application value and limits：The work directly demonstrates phosphate anchoring to an inorganic oxide through Zr-O-P bonds and provides a useful analogue for metal, glass and ceramic adhesion. It also shows an optimum concentration rather than a monotonic dose response. The study addresses dental zirconia and methacrylate systems rather than an industrial coating directly. Hydroxyl density differs among metals, glass and ceramics, so the optimum will shift. Acid effects on cure, storage and filler compatibility must also be tested.