• Title/Summary/Keyword: dental amalgam

검색결과 143건 처리시간 0.03초

치과용 아말감의 미세경도에 관한 실험적연구 (AN EXPERIMENTAL STUDY ON THE MICROHARDNESS OF DENTAL AMALGAMS)

  • 신동훈
    • Restorative Dentistry and Endodontics
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    • 제8권1호
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    • pp.89-96
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    • 1982

  • The purpose of this study is to identify the phases of four different types, low-copper lathe cut (Type II, class 1) and spherical (Type II, class 2) amalgam alloys which are made by Caulk company and high copper Dispersalloy (Type II, class 3) made by Johnson & Johnson and Tytin (Type I, class 2) made by S.S. White and to determine the Vickers hardness number on the individual phase and four different types of dental amalgam. After each amalgam alloy and Hg measured exactly by the balance was triturated by the mechanical amalgamator (De Trey), the triturated mass was inserted into the cylindrical metal mold which was 4 mm in diameter and 12mm in height and was pressed by the Instron Universal Testing machine (Model 1125) at the speed of 1mm/minute with 143$kg/cm^2$ according to the A.D.A. Specification No. 1. The Specimen removed from the mold, mounted and stored in the room temperature for 7 days. The speciman was polished with the emery paper from #220 to #1200 and finally on the polishing cloth with 0.3 and 0.05 um $Al_2O_3$ powder suspended in water. And then each specimen was etched by Allan's method and washed with Sodium Bisulfinite for 30 seconds. Finally differentiation and metallography on each phase were obtained by using metallographical microscope (Versamet, Union) and microhardness was obtained by using microhardness tester (MVH-2, Torsee). The results were as follows: 1. In the low-copper amalgam, the ${\gamma}$, ${\gamma}_1$ and ${\gamma}_2$ phase were observed and in the high-copper amalgam, the ${\gamma}$, ${\gamma}_1$. ${\epsilon}$ and ${\eta}$ phases were observed but ${\gamma}_2$ phase was not observed. 2. Among the microhardness of each amalgam phase measured under pressing a vickers diamond indenter with 2.0gm load for 30 seconds, e phase has the highest V.H.N (314 ${\pm}$ 20), and in low-copper amalgam 12 phase has the lowest V.H.N. (29${\pm}$1) and ${\eta}$ phase which was observed in high-copper amalgam has 230${\pm}$13 V.H.N and this phase is considerd to contribute to strengthen the handness in amalgam. 3. The V.H.N. measured under pressing a Vickers diamond indenter with 300.0gm load for 30 seconds in low-copper amalgam was lower than that of high-copper amalgam.

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수종 아말감과 금합금의 갈바닉 전류 측정에 관한 연구 (A STUDY ON THE REDUCTION OF GALVANIC CURRENT BETWEEN AMALGAM AND GOLD ALLOY WITH VARIOUS CHEMICAL AGENTS)

  • 김승수;엄정문
    • Restorative Dentistry and Endodontics
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    • 제18권2호
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    • pp.469-481
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    • 1993

  • The purpose of this study was to achieve the reduction of the galvanic current between the dental amalgam alloy and gold alloy. In order to measure the galvanic current between these two metals a prep in the size of $4{\times}13mm$ which was filled with amalgam and another prep of $4{\times}2mm$ was filled with gold alloy was made in the acrylic resin. These two preps were then connected to a 2mm diameter copper wire. Using an ammeter to measure the galvanic current, six different kinds of amalgam and gold alloy were immersed in saline solution with approximately 10mm distance between the two alloys. Chemical agents that are thought to reduce the galvanic current such as hydrazine. silver nitrate, potassium chromate, and bonding agents such as Scotch bond 2(3M) and All bond 2(Bisco) were applied to the alloy surface. Cathodic inhibitor such as hydrazine was applied to gold alloy where as anodic inhibitor such as silver nitrate and potassium chromate were applied to amalgam. Both bonding agents, Scotch bond 2(3M) and All bond 2 (Bisco), were applied to amalgam. The following results were obtained when the currency on the coated alloy surface was compared to the uncoated surface. 1. The galvanic currency went down as the time elapsed and after 30 minutes no change was detected. 2. Initial currency was higher in low copper amalgam compared to high copper amalgam. Intitial currency was the highest in low copper lathe-cut amalgam. 3. Group of gold coated with hydrazine had the most reduction in galvanic currency. 4. Group of amalgam coated with silver nitrate or potassium chromate also showed significant reduction in galvanic currency. 5. The bonding agents also helped reduce galvanic currency. 6. Of all the agents used to reduce galvanic currency, silver nitrate showed the best result.

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접착형 아말감의 2년 후 임상적 평가 (CLINICAL EVALUATION OF AMALGAM BONDING : TWO YEARS FOLLOW-UP)

  • 유필준;한세현;김종철
    • 대한소아치과학회지
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    • 제28권3호
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    • pp.530-534
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    • 2001

  • 많은 치과 임상가들은 아말감을 치질에 접착시키기 위해서 여러 접착재료를 이용해왔다. 이 런 술식의 장점으로는 미세누출의 감소로 인한 술후과민증의 감소, 변연파절의 감소, 삭제 후 치질의 강화, 적은 유지형태에서의 수복물의 유지등이 제시되어 왔다. 실제로 임상적 상황에서 이러한 술식의 장점을 확인할 필요가 있다. 이런 접착제가 임상적 환경에서 어떠한 잇점을 보이지 않는다면 시간과 비용을 낭비하는 이런 술식을 정당화하지 못할 것이다. 본 연구에서는 73개의 치아를 대상으로 하여 I급 와동과 II급 와동에 접착형과 비접착형 아말감으로 수복하였다. 접착제로는 Fuji I Glass Ionomer luting cement를 이용하였다. 평균 2년 후에 변연적합성을 평가하였으나 접착형 아말감과 비접착형 아말감 사이에 유의한 차이는 없었다.

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