Tensile bond strengths of three chemical and one electrolytic etching systems for a base metal alloy

Investigation into the effect of use of metal primer on adhesion of heat cure acrylic resin to cast titanium: an in vitro study

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.

Comparison of bond strengths of three denture base resins to treated nickel-chromium-beryllium alloy

PURPOSE

In-vitro bond strengths of 3 denture base resins (Trutone, Lucitone 199, and Triad) to a nickel-chromium-beryllium removable partial denture alloy (Ticonium) were tested with 3 surface pretreatments: sandblast, acid etch, and Rocatec (silica blasting), with or without primers (Dentsply, CR inlay cement, and Super Bond).

MATERIAL AND METHODS

Lucitone 199 denture base resin bonded to the nonprimed sandblasted alloy specimen served as the control group. Alloy specimens were prepared, surface treated, and primed or not primed with primer. The treated specimens were then packed and processed with the denture base resin. Bonded specimens were stored in the distilled water at 37 degrees C for 24 hours, and then debonded in tension. The force at which the bond failed was noted, and bond strength was calculated in megapascals (MPa). Five replications for each condition (180 specimens total) were tested.

RESULTS

Significant differences in bond strength were observed with primer, the most important factor, followed by pretreatment and denture base resin. Without primer for all 3 denture base resins, the Met-Etch and Rocatec treated group showed significantly higher bond strengths than the sandblasted groups. For Trutone denture base resin, nonprimed treated groups produced significantly higher bond strength than those for the other 2 denture base resin, nonprimed treated groups produced significantly higher bond strength than those for the other 2 denture base resins. The control group had zero bond strength. For Dentsply primer, the Rocatec treated group bonded to Lucitone 199 resin produced the highest bond strength value (14.8 +/- 1.8 MPa). For CR inlay cement, the Met-Etch and Rocatec treated groups for Lucitone denture base resin demonstrated the highest bond strength (19.3 +/- 4.8 MPa, and 19.3 +/- 1.8 MPa, respectively). For super Bond primer, the Met-Etch treated group for Trutone resin demonstrated the highest bond strength (19.8 +/- 6.2 MPa).

CONCLUSIONS

Without primer, the control had the lowest bond strength (0 MPa), and the Trutone groups showed the highest bond strength (11.7 +/- 4.1 MPa). Met-Etch and Rocatec treated groups produced higher bond strengths than the sandblasted groups. The primed specimens demonstrated significantly higher bond strengths than nonprimed specimens, except for Trutone resin, for which primed specimens produced lower bond strengths than the nonprimed specimens.