Earticle

초록

영어

Passive fitting of meso-structure and super-structures is a predominant requirement for the longevity and clinical success of osseointegrated dental implants. However, precision and passive fitting has been unpredictable with conventional methods of casting as well as for corrective techniques. Alternative to conventional techniques, electro discharge machining(EDM) is an advanced method introduced to dental technology to improve the passive fitting of implant prosthesis. In this technique material is removed by melting and vaporization in electric sparks.
Regarding the efficacy of EDM, the application of this technique induces severe surface morphological and elemental alterations due to the high temperatures developed during machining, which vary between 10,000~20,000 .
The aim of this study was to investigate the morphological and elemental alterations induced by EDM process of casting dental gold alloy and non-precious alloy used for the production of implant-supported prosthesis.
A conventional clinical dental casting alloys were used for experimental specimens patterns, which were divided in three groups, high fineness gold alloy(Au 75%, HG group), low fineness gold alloy(Au 55%, LG group) and nonprecious metal alloy(Ni-Cr, NP group). The UCLA type plastic abutment patterns were invested with conventional investment material and were cast in a centrifugal casting machine.
Castings were sandblasted with 50 Al2O3. One casting specimen of each group was polished by conventional finishing(HGCON, LGCON, NPCON) and one specimen of each group was subjected to EDM in a system using Cu electrodes, kerosene as dielectric fluid in 10 min for gold alloy and 20 min for Ni-Cr alloy(HGEDM. LGEDM, NOEDM). The surface morphology of all specimens was studied under an energy dispersive X-ray spectrometer (EDS).
The quantitative results from EDS analysis are presented on the HGEDM and LGEDM specimens a significant increase in C and Cu concentrations was found after EDM finishing. The different result was documented for C on the NPEDM with a significant uptake of O after EDM finishing, whereas Al, Si showed a significant decrease in their concentrations.
EDS analysis showed a serious uptake of C and Cu after the EDM procedure in the alloys studied. The C uptake after the EDM process is a common finding and it is attributed to the decomposition of the dielectric fluid in the plasma column, probably due to the development of extremely high temperatures. The Cu uptake is readily explained from the decomposition of Cu electrodes, something which is also a common finding after the EDM procedure.
However, all the aforementioned mechanisms require further research. The clinical implication of these findings is related with the biological and corrosion resistance of surfaces prepared by the EDM process.

목차

[Abstract]
 Ⅰ. 서론
 Ⅱ. 실험재료 및 방법
  1. 실험재료
  2. 실험방법
 Ⅲ. 실험결과 및 고찰
 Ⅳ. 결론
 참고문헌

키워드

저자

• 장용철 [ Yong-Chul Jang | 월드치과기공소 ]
• 이명곤 [ Myung-Kon Lee | 부산가톨릭대학교 생명과학대학원 치기공학과 ]

참고문헌

발행기관

간행물

표지보기 관심저널 등록

• 간행물명

  대한치과기공학회지 [THE JOURNAL OF KOREAN ACADEMY OF DENTAL TECHNOLOGY]

• 간기

  계간

• pISSN

  1229-3954

• eISSN

  2288-5218

• 수록기간

  1979~2026

• 등재여부

  KCI 등재

• 십진분류

  KDC 515 DDC 617