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Published on: January 17, 2025
Bonding of autopolymerizing denture base resin to cast Type IV gold alloy
Hiroshi Shimizu1, Yuzo Tachii, Yutaka Takahashi
1Division of Removable Prosthodontics, Department of Oral Rehabilitation, Fukuoka Dental College, 2-15-1, Tamura, Sawaraku, Fukuoka 814-0193, Japan. simizuh1@college.fdcnet.ac.jp
Purpose:
To evaluate the shear bond strengths of an autopolymerizing denture base resin to cast Type IV gold alloy using four metal conditioners.
Methods:
Type IV gold alloy discs were cast. The disc surfaces were sandblasted with 50 microm alumina particles and primed with four metal conditioners (Metaltite; Alloy Primer; Metal Primer II; and V-Primer). An autopolymerizing denture base resin was applied on an area of the discs defined by a hole punched in a piece of sticky tape and by a Teflon ring. All the specimens were immersed in 37 degrees C distilled water for 24 hours. Half of the specimens were thermocycled up to 20,000 cycles in water between 4 degrees C and 60 degrees C with a dwell time of 1 minute at each temperature. The shear bond strengths were determined at a crosshead speed of 1.0 mm/minute. The data was analyzed using a 2-way ANOVA (P < 0.05).
Results:
The shear bond strengths of the autopolymerizing denture base resin to cast Type IV gold alloy specimens primed with the four metal conditioners (P < 0.05) were significantly enhanced. However, the bond strength was reduced for all thermocycled groups (P < 0.01). Metaltite exhibited the greatest pre- and post-thermocycling bond strength (27.5 and 22.4 MPa) compared to the other groups (P < 0.05).

