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무가압 분말충전 알루미나에 이트리아를 함유한 붕규산염 유리를 침투시킨 코아 도재의 물성

Other Titles
 (The) physical properties of Y2O3-containing glass infiltrated alumina core made by pressureless powder packing 
Authors
 황승우 
Issue Date
1997
Description
치의학과/박사
Abstract
[한글]

본 연구에서는 평균입경 4㎛의 알루미나를 무가압 분말 충전법으로 성형하고 1350℃에서 1시간동안 1차 소결한 후, 열팽창 계수가 서로 다른 6종의 이트리아를 함유한 붕규산염 유리를 1300℃에서 2시간동안 침투시켜 제작한 알루미나/유리 복합체와, slip casting 법으로 제작한 In-Ceram의 꺽임강도, 수축율, 경도, 파괴 인성 등을 측정 ,비교하고, 알루미나 입자와 유리의 열팽창 계수의 불일치가 알루미나/유리 복합체의 물성에 미치는 영향을 관찰하여 다음과 같은 결과를 얻었다.

1. 실험군과 In-Ceram간의 꺽임 강도는 1군과 3군이 In-Ceram과 통계학적인 유의차가 없었으며, 그 외의 실험군에서는 In-Ceram보다 낮은 값을 보였다.

2. 실험군의 수축율은 1차 소결 후 0.42%, 유리 침투 후 0.45%가 발생하여, 총 0.87%의 수축이 발생하였다.

3. 1차 소결한 실험군과 In-Ceram의 기공율은 각각 50%와 22.25%로 큰 차이를 나타냈으나, 유리를 침투한 후에는 각각 2%와 1%를 보여 큰 차이가 없었다.

4. 두 재료간의 경도는 통계학적인 유의차가 없었으며, 파괴인성에 있어서는 2군과 3군이 In-Ceram보다 더 높은 수치를 나타내었다. 그 외의 군들은 In-Ceram과 통계학적인 유의차가 없었다.

5. 실험군의 열팽창 계수는 4.51∼5.35×10**-6 /℃를 나타내었으며 이에 따라 꺽임강 도에도 차이가 있었다.

6. 주사전자현미경 소견에서는 In-Ceram에서 4㎛의 입자뿐 아니라 0.5㎛정도의 미세입자가 다량 관찰되었으며, 실험군에서는 necking이 미약하게 발생한 4㎛의 입자들이 주로 관찰되었다.

이상의 결과에서 볼 때 알루미나 입자와 유리의 열팽창 계수의 불일치는 알루미나 입자와 유리의 결합력을 증진시키는 요소로 작용하며, 성형법과 기공율은 도재의 강도에 큰 영향을 미치지 않았다. 알루미나 입자와 유리의 열팽창 계수의 불일치가 가장 컸던 3군의 물리적 성질이 가장 우수하였으며, 향후 이를 임상응용시킬 수 있는 연구가 지속된다면 무가압 충전법을 응용한 우수한 성질을 갖는 전부 도재관의 제작이 가능하리라고 사료된다.

[영문]

The objective of this study was to characterize the mechanical properties of Y^^2 0^^3 -containing glass infiltrated ceramic core material, which was made by pressureless powder packing method. A pure alumina powder with a grain size of about 4㎛ was packed without pressure in silicon mold to form a bar shaped sample, and applied PVA solution as a binder. Samples were sinters at 1350℃ for 1 hour. After cooling, Y^^2 O^^3-containing glass (SiO^^2, Y^^2 O^^3, B^^2 O^^3, Al^^2 0^^3 ,

etc) was infiltrated to the sinterd samples at 1300℃ for 2 hours and cooled. Six different proportions of Y^^2 O^^3 were used to know the effect of the mismatch of the thermal expansion coefficient between alumina powder and glass. The samples were ground to 3×3×3O ㎜ size and polished with 1㎛ diamond paste. Flexural strength, fracture toughness, hardness and other physical properties were obtained , and the fractured surface was examined with SEM and EPMA. Ten samples of each group were tested and compared with In-Ceram**TM core materials of same size made in dental laboratory.

The results were as follows :

1. The flexural strengths of group 1 and 3 were significantly not different with that of In-Ceram, but other experimental groups were lower than In-Ceram.

2. The shrinkage rate of samples was 0.42% after first firing, and 0.45% after glass infiltration. Total shrinkage rate was 0.87% .

3. After first firing, porosity rate of experimental groups was 50% , compared with 22.25% of In-Ceram. After glass infiltration, porosity rate of experimental groups was 2%, and 1% in In-Ceram.

4. There was no statistical difference in hardness between two materials tested, but in fracture toughness, group 2 and 3 were higher than In-Ceram.

5. The thermal expansion coefficients of experimental groups were varied to 4.51∼5.35×10**-6 /℃ according to glass composition, also the flexural strengths of samples were varied.

6. In a view of SEM, many microparticles about 0.5㎛ diameter and 4㎛ diameter were observed in In-Ceram. But in experimental group, the size of most particles was about 4㎛, and a little microparticles was observed.

The results obtained in this study showed that the mismatch of the thermal expansion coefficients between alumina powder and infiltrated glass affect the flexural strength of alumina/glass composite. The Y^^2 O^^3 -containing glass infiltrated ceramic core made by powder packing method will takes less time and cost with sufficient flexural strength similar to all ceramic crown made with slip casting technique.
Full Text
https://ymlib.yonsei.ac.kr/catalog/search/book-detail/?cid=CAT000000005104
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Appears in Collections:
2. College of Dentistry (치과대학) > Dept. of Advanced General Dentistry (통합치의학과) > 3. Dissertation
URI
https://ir.ymlib.yonsei.ac.kr/handle/22282913/125454
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