Investigation into the Effect of Use of Metal Primer on Adhesion of Heat Cure Acrylic Resin to Cast Titanium: An In Vitro Study

Abstract

The availability of adhesive primers capable of bonding chemically to base metal alloys without well defined passive oxide surface film has been improved significantly over the last decade. Therefore, the purpose of the study was to compare and evaluate the effect of metal primer on adhesion of heat cure acrylic resin to cast titanium. Shear bond strength test was conducted on 80 commercially pure titanium cast metal heat-cure acrylic resin discs treated with different surface treatments. The first group received no surface treatment (group I); the second group was subjected to sandblasting (group II); the third group was treated with bonding agent (alloy primer) (group III) and the fourth was treated with sandblasting and alloy primer (group IV). After the samples were surface treated, acrylic resin was mixed, packed and processed over the test area of cast titanium. Ten specimens of each group were immersed in distilled water for 24 h followed by thermocycling for 20,000 cycles. Shear bond-strength between the heat cure acrylic resin and titanium was evaluated using Instron universal testing machine. Debonded specimens of all the groups were subjected to SEM analysis. The bond failure (MPa) was analyzed by ANOVA and Duncan's multiple comparison tests. Surface treatment with sandblasting, followed by the application of alloy primer showed maximum shear bond strength before and after thermocycling (24.50 ± 0.59 and 17.39 ± 1.56 MPa respectively).The bond strength values are found to be in decreasing magnitudes as group IV > group III > group II > group I. The following pretreatment to improve the shear bond strength of heat cure acrylic resin to titanium is recommended in order to attain the maximum bond strength in cast titanium frameworks for various prostheses: sandblasting, cleaning in an ultrasonic bath for 10 min and air drying followed by application of a bonding agent uniformly on the sandblasted cast titanium surface before packing with heat cure acrylic resin.

Removing Fractured Endodontic NiTi Instruments with a Tube Technique: Influence of Pre-Treatment with Various Agents on Adhesive Forces In Vitro

“…Metalprimer directly affects surfaces of alloys by creating reactive molecules ( Figure 3B,C) allowing a chemical bond between the composite and the NiTi alloy [28]. In general, Metalprimers contain VBATDT (5-(4-vinylbenzyl)-2-thiobarbituric acid (5VS), 6-(4-vinylbenzyl-n-propyl) amino-1,3,5-triazine-2,4-dithione), MDP (10-Methacryloyloxydecyl Dihydrogen Phosphate) and/or MMA (Methyl methacrylate).…”

“…These ingredients guarantee improved bond strengths to both precious and non-precious metals. The coupling mechanism is based on the following aspects: i) the transformation of thione (-C=S) to thiol (-C-S-H) groups on the metal surface (M) then leading to a primary bond formation (-C-S-M) and (ii) the co-polymerization of vinyl groups with the methacrylate-based resin monomer [28]. Additionally, Metalprimer even improve adherence of resins to NiTi alloys [27,29].…”

Comparison of the effectiveness of Tokuyama and GC II metal primer on the bond strength of acrylic resins to Ti-6Al-7Nb

“…Numerous studies have established that application of primers significantly improve the bond strength of the acrylic resin to the cast metals, Ti-6Al-4 V, CP-Ti, composites, and ceramics. [ 8 9 10 23 24 25 26 27 28 29 30 31 32 ] However, the comparative evaluations of bond strength between acrylic resin and Ti-6Al-7Nb with the use of Tokuyama primer and GC II metal primer have never been documented. In the present study, the tensile bond strength of Ti-6Al-7Nb to acrylic resins was significantly ( P < 0.001) improved by primer application compared to control group [ Graph 1 ].…”