• Title/Summary/Keyword: 아말감 합금

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Restoration of gold guilding on Geumdong-samjonpanbul excavated from Walji, Gyeongju using plum acid & gold(Au)-mercury(Hg) amalgam (매실산과 금아말감을 이용한 월지 출토 금동삼존판불의 금도금법 복원)

  • Yun, Yong-Hyeon;Jo, Nam-Cheol;Lee, Tae-Seop
    • Proceedings of the Korean Institute of Surface Engineering Conference
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    • 2018.06a
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    • pp.6-6
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    • 2018
  • 본 연구에서는 고문헌에 기록된 도금 재료와 도금법 등을 확인하고 이를 기초자료로 활용하여 매실산을 사용한 금(Au)-수은(Hg) 아말감기법으로 고대 도금(鍍金)기술을 되살리고, 이를 토대로 경주 월지에서 출토된 금동삼존판불을 복원하였다. 먼저, 전통 도금법을 되살리기 위해서, "오주서종박물고변", "확지신편", 조선시대 각종 의궤 등에 공통적으로 기록되어 있는 매실에 주목하고, 매실을 3~4개월 발효 숙성 후 착즙한 뒤 그것을 농축하여 만든 매실산을 도금 실험에 적용하였다. 금아말감 도금을 위하여 월지 출토 금동삼존판불의 바탕소지금속인 청동삼존판불을 구리와 주석 89:11(Cu:6kg, Su:750g)로 합금하여 주물사 주조법으로 복원하였으며, 동일한 합금비로 제작된 $2.3cm{\times}3.5cm$(가로${\times}$세로)의 시편에 사전 실험을 실시하였다. 현대적 산처리 방식에 사용되는 질산과 전통방식으로 사용되는 매실산으로 시편에 산처리 한 후 각각 비교해 보고, 금분과 금박, 상온과 가온에 따른 아말감상태를 비교하는 실험을 진행하였는데, 실험에 사용된 매실산 70%는 pH가 1.94로, 오늘날 산처리에 사용하고 있는 질산 20%와는 차이가 있지만, 청동 시편 실험을 통해 매실산에 20분 정도 담근 뒤 금아말감을 도포 후 24시간 지나 가열($380{\sim}400^{\circ}C$) 했을 때 금도금이 잘 되어, 현대적 방법인 질산처리로 도금을 한 시편과 큰 차이가 없는 것으로 관찰되었다. 사전 실험을 통한 결과를 적용한 월지 출토 금동삼존판불 복원은 청동삼존판불 표면처리, 금-수은 합금 및 도금하기, 도금 후 표면처리의 순서로 진행되었는데, 금과 소지금속의 밀착력을 높이기 위해 표면을 숯을 이용해 탈지한 후 물로 씻어내고 매실산을 도포하여 20분 동안 두어 부식 및 세척을 시행하였다. 금도금을 위한 금-수은아말감은 가온할 때 수은이 증발하는 양을 고려하여 금1 : 수은10 비율로 합금하여 완성하였으며, 금아말감 도포 후 약 24시간 지난 다음, $380{\sim}400^{\circ}C$에 가열하여 수은을 기화시켜 도금작업을 완성하였다. 금아말감도금은 평균적으로 6~7차례 시행하여야 완벽히 도금되지만, 본 연구에서는 단 4차례의 도금만으로 금아말감도금을 완성시켰는데, 이것은 금아말감을 바탕소지인 청동에 도포한 후 24시간 동안 금아말감과 청동과의 반응 시간을 두게한 것이 큰 역할을 한 것으로 보이며, 이는 청동시편을 이용한 실험과 과학적 분석을 통하여 입증하였다. SEM으로 표면을 관찰한 결과 아말감 도포시간이 즉시인 경우 도금이 거의 되지 않은 것을 확인할 수 있었고 36시간이 넘어갈 경우 금 도금층이 불균일하게 관찰되었으므로 도금시간은 12시간~24시간 이내가 적절함을 확인할 수 있었다. EDS로 성분을 분석한 결과 산처리 시간이 20분인 시료의 경우 5 wt% 내외로 수은의 비율이 다른 시료에 비해 낮은 것을 확인할 수 있었다. 실험 및 분석결과 산처리 시간이 20분이고 아말감 도포시간이 24시간일 때 도금이 잘 이루어지므로 이 결과를 토대로 금동삼존판불을 복원하였다. 이번 연구를 통해 도금법에 표면을 세척하고 부식시키기 위해 사용한 물질이 매실산임을 찾아내어 확인할 수 있었는데, 이러한 점 에서 이 연구의 가장 큰 의미는 전통 소재와 기술을 복원한 것으로, 앞으로 매실산을 이용한 금 도금기술은 관련 학계에도 큰 기여를 할 것으로 기대된다.

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A Study on Corrosion according to Distance between Amalgam and Dissimilar Metals (아말감과 이종(異種)금속의 거리에 따른 부식에 대한 고찰)

  • Kim, Ju-won;Jeong, Eun-gyeong
    • Journal of dental hygiene science
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    • v.4 no.3
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    • pp.103-109
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    • 2004
  • The present study prepared 72 test samples - 24 made of amalgam alloy, 24 of Verabond (Ni-Cr alloy) for crown and 24 of Talladium $^{TM}alloy$ for denture - according to the manufacturers' manuals and general method in consideration of the width of the mesial-distal dental crown of the lower $1^{st}$ molar and MOD cavity in clinics, put them in a 200 ml beaker containing 80 ml of artificial saliva, and measured their galvanic corrosion at distances of 0 mm, 7 mm and 40 mm after 7 days. Isolated metals in the electrolyte such as Cu, Ag, Ni, Cr, Sn, Zn and Hg were quantitatively analyzed with Inductively Coupled Plasma - Atomic Emission Spectrometer (ICP-AES, JY-50P, VG Elemental Co. France), and from the results were drawn conclusions as follows. First, Cu, Sn, Ag, Hg and Zn were highly advantageous when amalgam contacted gold alloy compared to Ni-Cr alloy for crown and Talladium alloy for denture. In addition, although gold alloy was finest in terms of oral tissue and biocompatibility, it was most disadvantageous when it was with amalgam. Second, when amalgam contacted gold alloy, heavy metals such as Ni and Cr were not isolated at all because gold alloy did not contain such elements but Sn was isolated as much as $227.1{\pm}18.0035{\mu}g/cm^2$ although it was not included in the composition either. Hg was also isolated. These elements are assumed to have been isolated from amalgam itself. Third, when amalgam alloy was apart from gold alloy 0 mm, 7 mm and 40 mm, Cu and Ag showed significance but Hg did not. This suggests that gold alloy must not be used together with amalgam, and must not be used between dissimilar prostheses regardless of distance. Fourth, when amalgam alloy contacted Ni-Cr alloy for crown, Ag was not isolated from the amalgam, but Zn, Ni, Sn, Hg and Cu were isolated in order of quantity. Significance was observed according to distance - 0 mm, 7 mm and 40 mm. Hg was not isolated but heavy metals Ni and Cr were isolated. If amalgam alloy was in the opposite arch or it was apart from Ni-Cr alloy for crown, the isolation Hg was less than that when amalgam alloy contacted Ni-Cr alloy for crown. Fifth, when amalgam alloy contacted Talladium alloy for denture, significance was observed at distances of 0mm, 7 mm and 40 mm. Hg was not isolated but heavy metals Ni and Cr were isolated. If amalgam alloy was in the opposite arch or it was apart from Talladium alloy for denture, the isolation Hg was less than that when amalgam alloy contacted Talladium alloy for denture. Sixth, according to the result of ICPES test on Cu, Sn, Ag, Hg, Zn, Ni and Cr of amalgam alloy, gold ally, Verabond and Talladium alloy when these alloys contacted artificial saliva, significance was observed in Cu and Hg. Seventh, when amalgam alloy contracted two non-precious metals Ni-Cr alloy for crown and Talladium alloy for denture in artificial saliva, significance was observed in the isolated by-products of Hg, Ni and Cr according to distance.

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MARGINAL SEALING OF AMALGAM RESTORATIONS USING DENTIN BONDING ADHESIVES (아말감수복시 상아질접착제가 변연봉쇄에 미치는 영향)

  • Lee, Sang-Hoon;Lee, Keung-Ho
    • Journal of the korean academy of Pediatric Dentistry
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    • v.29 no.1
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    • pp.57-68
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    • 2002
  • The purpose of this study was to evaluate microleakage of etched and non-etched amalgam restorations lined with dentin bonding system primer and adhesives. Class V amalgam preparations were made in 100 extracted human premolars divided into 10 groups with 10 teeth each. SEM was taken to assess the dentin/amalgam interface. The results were as follows; 1. At the occlusal and gingival margins, all experimental groups showed lower leakage value than unlined group(p<0.05) The $Copalite^{(R)}-lined$ group showed higher leakage value than other experimental groups(p<0.05). 2. In all experimental groups, the gingival margin showed higher leakage value than the occlusal margin. 3. There were no significant difference between non-etching and etching groups, primer only and primer & adhesive groups, primer & adhesive and self-priming adhesive groups(p>0.05). 4. On the SEM observation, continuous gaps were observed in the unlined and $Copalite^{(R)}-lined$ groups, but the gaps were filled with primer or adhesive layer in other experimental groups.

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A Study on occurrence of porosity and leakage of mercury in dental amalgam's inside (치과용 아말감 내부의 수은 유출과 기포의 발생에 관한 연구)

  • Kim, Joo-Won
    • Journal of Korean society of Dental Hygiene
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    • v.10 no.3
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    • pp.531-540
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    • 2010
  • Objectives : In this study, following the cavity restorations with low copper conventional alloy, high copper admixed one and high copper unicompositional one, which are used the most frequently in a clinical setting at the present, to experiment the time-dependent changes of strength, bubbles were examined. Besides, to examine the detrimental effects of mercury contained in dental amalgam, the amount of mercury release was evaluated. Methods : As dental amalgams which were used herein, [BESTALOY], [Hi-Aristaloy 21] and [Sybraloy] were selected for a low-copper conventional amalgam, a high-copper admixed one and a high-copper unicompositional one in the corresponding order. The formation of bubbles and the weight ratio of mercury release were evaluated using a field emission scanning electron microscope (FE-SEM). Thus, the following results were obtained: Results : 1. The time-dependent amount of mercury release reached a statistical significance in three types of alloys, which was shown in such a descending order as [BESTALOY], [Hi-Aristaloy 21] and [Sybraloy]. 2. A low-copper conventional type, BESTALOY is a cutting type and it was found to have an increased formation of fine bubbles. In the remaining two types, [Hi-Aristaloy 21] (a high-copper admixed alloy) and [Sybraloy] (a high-copper unicompositional alloy), the time-dependent changes in the formation of bubbles was negligible. Conclusions : Accordingly, this type of mercury release from amalgam alloy denotes the difference in the weight ratio of total constituents between after 24 hours and after two weeks. But further studies are warranted to examine the amount of mercury release which is detrimental to human bodies. Besides, a low-copper conventional alloy is a cutting type and it was characterized by the abundant formation of bubbles in a time-dependent manner. This implies that the strength of amalgam is impaired, which should be considered in selecting the appropriate amalgam alloy in a clinical setting.