Use of metal conditioners to improve bond strengths of autopolymerizing denture base resin to cast Ti-6Al-7Nb and Co-Cr.
OBJECTIVE
The shear bond strengths of an autopolymerizing denture base resin to cast Ti-6Al-7Nb and Co-Cr alloys using three metal conditioners were investigated.


METHODS
Ti-6Al-7Nb alloy and Co-Cr alloy discs were cast. The disc surfaces were air-abraded with 50 microm alumina particles and treated with three metal conditioners (Alloy Primer; Cesead II Opaque Primer; Metal Primer II). An autopolymerizing denture base resin was applied on the discs within a hole punched in a piece of sticky tape and a Teflon ring to define the bonding area. All specimens were immersed in 37 degrees C water for 24 h. Half of the specimens were thermocycled up to 20,000 cycles. The shear bond strengths were determined at a crosshead speed of 1.0 mm/min.


RESULTS
Specimens treated with the three metal conditioners had significantly (p<0.05) improved shear bond strengths of the autopolymerizing denture base resin to both Ti-6Al-7Nb and Co-Cr. Although the bond strengths of the bonded Ti-6Al-7Nb specimens were higher than those of the Co-Cr alloy before thermocycling, the decrease in the bond strength of Ti-6Al-7Nb was considerably greater than that of the Co-Cr after thermocycling.


CONCLUSIONS
Significant improvements in bond strength of the autopolymerizing denture base resin to cast Ti-6Al-7Nb alloy and Co-Cr alloy were achieved through the application of Alloy Primer, Cesead II Opaque Primer and Metal Primer II. The bond durability to Ti-6Al-7Nb alloy was inferior to that to Co-Cr.
Division of Removable Prosthodontics, Department of Oral Rehabilitation, Fukuoka Dental College, 2-15-1 Tamura Sawara-ku, Fukuoka 814-0193, Japan. simizuh1@college.fdcnet.ac.jp
Hiroshi
H
Shimizu
Kenneth S
KS
Kurtz
Yuzo
Y
Tachii
Yutaka
Y
Takahashi
D002858:Chromium Alloys / Q000737:chemistry; D001840:Dental Bonding / Q000379:methods*; D003819:Denture Bases; D008669:Metallurgy / Q000379:methods; D033081:Shear Strength; D014025:Titanium / Q000737:chemistry
D002858:Chromium Alloys; C103771:cobalt-chromium-molybdenum-carbon alloy; C070282:Ti-6Al-7Nb alloy; D014025:Titanium