THE EFFECT OF SPRUE DESIGN ON THE INTERNAL POROSITY OF TITANIUM CASTINGS

주입선 설계가 티타늄 주조체의 내부기포 발생에 미치는 영향

  • Heo Sook-Myeong (Department of Prosthodontics, Collage of Dentistry, Pusan National University) ;
  • Jeon Young-Chan (Department of Prosthodontics, Collage of Dentistry, Pusan National University) ;
  • Jeong Chang-Mo (Department of Prosthodontics, Collage of Dentistry, Pusan National University) ;
  • Lim Jang-Seop (Department of Prosthodontics, Collage of Dentistry, Pusan National University) ;
  • Jeong Hee-Chan (Department of Prosthodontics, Collage of Dentistry, Pusan National University)
  • 허숙명 (부산대학교 치과대학 보철학교실) ;
  • 전영찬 (부산대학교 치과대학 보철학교실) ;
  • 정창모 (부산대학교 치과대학 보철학교실) ;
  • 임장섭 (부산대학교 치과대학 보철학교실) ;
  • 정희찬 (부산대학교 치과대학 보철학교실)
  • Published : 2006.04.01

Abstract

Statement of problem: The high melting temperature and chemical reactivity of titanium necessitates casting machines different from those used in conventional casting. Despite the new developments in Ti casting systems , inadequate mold filling and internal porosity are frequently observed casting defects. Therefore, the study on the fabrication technique including sprue design to solve these casting defects is still necessary. Purpose: The purpose of this study was to evaluate the effect of sprue design and cross sectional area of sprue on the internal porosity. Materials and methods: 30 simulated cast three units titanium crowns were prepared. 5 cast crowns for each with different sprue design(sinlge sprue, double sprue and plate sprue) of two cross sectional areas (small and large cross sectional areas) were fabricated. The sections of titanium castings were photographed in a microscope at ${\times}100$ magnification to record internal porosities. Results and Conclusion: Within the limits of this study, the following conclusions were drawn: 1. There was a significantly lower in internal porosity of titanium castings for large cross sectional area of sprue group than the small group (P<.05) 2. There was no significant difference in internal porosity among sprue designs in similar cross sectional area of sprue (P>.05).

Keywords

References

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