Durability of Bond Strength between Titanium and two PMMAs

Abstract

The purpose of this study was to determine the durability of the bond strength between titanium and PMMA denture base resins. Two commercial PMMA denture base resins and three bonding systems were used in the present study.  A total of 224 rod shaped specimens of Grade 2 titanium alloy were divided into 16 groups of 14 each.  Half of the titanium rods were treated with 50 µm alumina air abrasion and a primer. Specimen had a heat-cured resin or a microwave-cured resin, that was applied as a secondary cylindrical shape having an outer diameter of 15 mm to treated surface of the titanium rod.  Half of the specimens in each group were stored in distilled water at 37°C for 24 hours.  The remaining of specimens were thermo-cycled for 10,000 cycles in water at 4°C and 60°C.  The shear bond strength was determined using the Shell-Nielsen test and the data were analyzed using ANOVA (p=0.05).  The initial bond strength between titanium and PMMA ranged from 0 to 25.9 MPa. After thermo-cycling, the bond strength ranged from 0 to 19.0 MPa. Regardless of the surface treatment and curing method, the bond strength of titanium and PMMA was significantly decreased after thermo-cycling.  It was found that bonding efficiency deteriorated after thermo-cycling.  The results suggest that a combination of air abrasion and priming as surface treatment prevents the debonding between titanium and PMMAs during their service life.

Keywords: metal adhesive primer, air abrasion, pure titanium, denture base resin, shear bond strength, durability, thermo-cycle