Journal of Technologic Dentistry (대한치과기공학회지)

Korean Academy of Dental Technology (대한치과기공학회)
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Effects of special heat treatment on changes in the hardness of a metal-ceramic alloy during the firing process

금속-도재 보철용 합금의 열처리가 소성과정 중 경도 변화에 미치는 영향

  • Sung-Min Kim (Department of Dental Laboratory Technology, Jinju Health College)
  • Received : 2023.08.07
  • Accepted : 2023.09.13
  • Published : 2023.09.30
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Abstract

Purpose: This study aimed to evaluate the effects of a special heat treatment on Pd-Au-Ag metal-ceramic alloy after degassing treatment and on changes in the hardness of the alloy during the firing process. Methods: Specimen alloys were cast and subjected to degassing at 900℃ for 10 minutes. These specimens were then subjected to a special heat treatment at 600℃ for 15 minutes in a dental porcelain furnace. Further, the specimens were subjected to simulated firing in the porcelain furnace. The resulting specimens were then tested for hardness, and changes in the microstructure were observed. Results: There was a decrease in the hardness of the alloy during the simulated firing of the cast alloy due to the coarsening of the particles. Meanwhile, additional heat treatment after degassing was found to play a crucial role in preventing a decrease in hardness. This treatment effectively suppressed the coarsening of the precipitates during repeated firing at high temperatures. Conclusion: Specific heat treatment of the Pd-Au-Ag metal-ceramic alloy prevented a decrease in its hardness and extended the lifespan of the metal-ceramic prosthesis.

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References

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