Effect of the type of acidic monomer on the bond durability of two-bottle type ceramic primer

Abstract

Ceramic primers consisting of γ-methacryloxypropyl trimethoxysilane (γ-MPS) and either 4-methacryloyloxyethyl trimellitate (4-MET) or 10-methacryloyloxydecyl dihydrogen phosphate (MDP) are useful for facilitating bonding of resin cement to silica-based ceramic surfaces. However, bond stability at the resin-ceramic interface differs among commercial ceramic primers. To determine the ability of 4-MET or MDP to hydrolyze the methoxy group in γ-MPS, the author designed two-bottle experimental ceramic primers comprising γ-MPS solution and an activator solution of 4-MET or MDP. The effects of the type of acidic monomer on contact angle and ceramic bond durability of resin were investigated. MDP and 4-MET promoted chemisorption of γ-MPS on the ceramic surface and enhanced the ceramic bond strength of the resin. However, thermocycling decreased ceramic bond strengths, as reflected by the increased number of bonded specimens that exhibited interfacial resin failure. Bond strength was greater for 4-MET-activated ceramic primer than for the MDP-activated ceramic primer, although most bonded specimens exhibited interfacial resin failure. Degradation behavior differed between the 4-MET-activated and MDP-activated ceramic primers.