Shear bond strength of four commercial bonding systems to cpTi

Objectives. The purpose of this study was to evaluate the bond strength of veneering composite to commercially pure titanium (cpTi) using several different bonding systems and a post-cure heat treatment. Methods. Four commercial bonding systems (Cesead, Kuraray; New Metacolor, Sun Medical; Silicoater MD, Kulzer; Thermoresin LC II, GC) were evaluated. Bonding was attempted with the opaque resin provided by each bonding system as well as with the New Metacolor opaque resin. New Metacolor resin composite was used for the veneering composite. Half of the specimens were subjected to a post-cure heat treatment at 100°C for 30 min. The shear bond strengths were tested after aging the specimens in water at 37°C for 1 d and also after thermocycling for 16.5 d (20,000 cycles). Results. Strong bonds, exceeding 20 MPa, were achieved with all of the bonding systems with the exception of Thermoresin LC II, which is designed for noble metals. Bond strengths were only increased by the post-cure heat treatment for the New Metacolor system. Thermocycling caused a significant reduction in bond strength for the New Metacolor and the Thermoresin LC II systems. The use of the New Metacolor opaque resin produced increased bonding for the Silicoater MD and the Cesead systems, but the effect was eliminated after thermocycling. Significance. Strong, durable bonds can be achieved between composite and sandblasted cpTi, thus enhancing the usefulness of this metal for esthetic resin-veneered crowns and other fixed prosthetics.