치과주조용합금의 물성에 관한 비교연구

김철위,이용근 大韓齒科器材學會 1992 대한치과재료학회지 Vol.19 No.1

The purpose of this study was to evaluate the characteristics of five gold-silver-palladium alloys, six H.E dental casting alloys, three dental casting nickel-chromium alloys, four porcelain metals and four dental casting cobalt-chromium alloys being used in Korea. The following properties were studied: Vicker's hardness, ultimate tensile strength, elongation rate, melting temperature and yield strength. These tests were performed according to the KDA Specification No. 6: Dental casting cobalt-chromium alloys, KSP 5101: Dental nickel-chromium alloy plate, RANSI/ADA Specification No. 5: Dental casting alloys, RANSI/ADA Specification No. 14: Dental base metal casting alloys, JIS T 6101: Dental casting gold-silver-palladium alloys, JIS T 6102: Dental nickel chromium alloy plate, ISO Specification No. 1562: Dental casting gold alloys and FDI Specification No. 7: Dental casting gold alloys. From the experiments, the following results can be drawn: 1) In case of the dental casting gold-silver-palladium alloys, the Vicker's hardness number was VHN 171 to VHN 229, the ultimate tensile strength was 633.1 ±148.5 MPa to 771.9 ±29.5 MPa, the elongation rate was 19.7% to 23.3%, the yield strength was 616.0+141.3 MPa to 751.0±20.4 MPa and the melting temperature range was 937℃ to 1,221℃. 2) In case of the H.E dental casting alloys, the Vicker's hardness number was VHN 120 to VHN 234, the ultimate tensile strength was 329.4 MPa to 681.5 MPa, the elongation rate was 14.0% to 38.9%, the yield strength was 304.9 MPa to 820.1 MPa and the melting temperature range was 899℃ to 1,125℃. 3) In case of the dental casting nickel-chromium alloys, the Vicker's hardness number was VHN 77 to VHN 106, the ultimate tensile strength was 473.6 ±34.0 MPa to 501.7 ±31.7 MPa, the elongation rate was 16.11% to 75.36% and the yield strength was 430.1 ±40.8 MPa to 450.9 ±48.6 MPa. 4) In case of the dental porcelain alloys, the Vicker's hardness number was VHN 206 to VHN 300, the ultimate tensile strength was 784.3 ±12.1 MPa to 1,114.8 ±24.5 MPa, the elongation rate was 20.40% to 39.10% and the yield strength was 749.2 ±11.3 MPa to 1,049.7 ±23.6 MPa. 5) In case of the dental casting cobalt-chromium casting alloys, the Vicker's hardness number was VHN 155 to VHN 266, the ultimate tensile strength was 671.8 ±339.8 MPa to 876.8 ±26.2 MPa, the elongation rate was 16.77% to 24.46% and the yield strength was 676.1 ±295.0 MPa to 841.7 ±34.6 MPa.

치과주조용 Ti-Zr-Cr계 합금에서 Cr 함량변화가 부식저항성에 미치는 영향

박영준,강후원,이용렬,송호준,김민강 大韓齒科器材學會 2004 대한치과재료학회지 Vol.31 No.4

The purpose of this study was to develop new dental casting titanium (Ti) alloys having an excellent mechanical properties and good corrosion resistance as a substitute for c.p Ti and Ti-6Al-4V alloy (control groups). Ti-20Cr, Ti-2OZr and Ti-20Zr-XCr (X=2, 5, 10, 15) alloys (experimental groups) were designed for dental casting Ti alloys. Prior to casting prccedure, mother alloys were prepared by using vacuum arc melting with skull melting method. Argon-arc melting and argon/vacuum-pressure casting machine were used for making the specimens. The hardness, microstructure, and corrosion resistance were evaluated by using Vickers microhardness measurement, FE-SEM, and anodic polarization test. The results were as follows: 1. The Vickers microhardness (Hv) of Ti and Ti-6Al-4V alloy showed the values of 210 and 352, and Ti-20Cr and Ti-20Zr alloys showed the values of 341 and 259, respectively. As the Cr content increased from 0 to 15 % in Ti-20Zr-XCr (X=0, 2, 5, 10, 15) alloys, the Hv increased from 259 to 298, 457, 344, and 351, respectively. The microstructure of Ti-20Zr-XCr specimens showed significant difference by the concentration changes of Cr content showing acicular crystalline structure for Ti-20Zr-2Cr and Ti-20Zr-5Cr, and equiaxed crystalline structure for Ti-20Zr-10Cr and Ti-20Zr-15Cr. 2. Open-circuit potentials (E_(∝)) were rapidly decreased followed by steadiness as time elapse in all experimental groups except in Ti-20Z group. Ti-2OZr group showed an increase in E_(∝), from the first. 3. In potentiodynamic anodic polarization tests, all experimental groups showed more noble corrosion potential (E_(corr) than that of Ti-6Al-4V, and more basic E_(corr) than that of Ti. Especially, Ti-20Zr-10Cr alloy showed most favorable corrosion resistance among Ti-Zr-Cr alloys. 4. For Ti-20Zr-10Cr, Ti-20Zr-15Cr, and Ti-20Cr groups, which have more than 10% Cr content, the secondary corrosion potential shifted to noble direction in larger amounts than in the cases of control and other experimental groups. From these results, it was concluded that newly formulated Ti-20Zr-10Cr experimental alloy have adequate hardness and high corrosion resistance, and this alloy is promising candidate for a successful dental casting alloy.

치과용 주조합금의 주조방법에 따른 부식거동

최한철(Han-Cheol Choe),고영무(Yeong-Mu Ko) 한국표면공학회 2004 한국표면공학회지 Vol.37 No.5

The defects of partial denture frameworks are mainly shrinkage porosity, inclusions, micro-crack, particles from investment, and dendritic structure. In order to investigate a good casting condition of partial denture frameworks, the three casting alloys and casting methods were used and detected casting defects were analyzed by using electrochemical methods. Three casting alloys (63Co-27Cr-5.5Mo, 63Ni-16Cr, 63Co-30Cr-5Mo) were prepared for fabricating partial denture frameworks with various casting methods; centrifugal casting (Kerr, USA), high frequency induction casting (Jelenko Eagle, USA), vacuum pressure casting (Bego, Germany). The casting temperature was 1,380℃ (63Co-27Cr-5.5Mo and 63Ni-16Cr) and 1,420℃ (63Co-30Cr-5Mo). The casting morphologies were analyzed using FE-SEM and EDX. The corrosion test of the dendritic structure was performed through potentiodynamic method in 0.9% NaCI solutions at 36.5℃ and corrosion surface was observed using SEM. The defects of partial denture frameworks improved in the order of centrifugal casting, high frequency induction casting, and vacuum pressure casting method, especially, pore defects were found at part of clasp in the case of centrifugal casting method. The structure of casting showed dendritic structure for three casting alloys. In the 63Co-27Cr-5.5Mo and 63Co-30Cr-5Mo, α-Co and ε-Co phases were identified at matrix and γ-Ni₂Cr second phase were shown in 63Ni-16Cr. Also, the corrosion resistance of cast structure increased in the order of vacuum pressure casting, high frequency induction casting, and centrifugal casting method.

치과 도재용착 주조관용 비귀금속 합금의 반복주조가 기계적 특성 및 미세조직에 미치는 영향

최운재,신무학,정희선,고명원 대한치과기공학회 2003 대한치과기공학회지 Vol.25 No.1

Using a nickel-chrome casting alloy called 'Rexillium V' which is also available as base metalalloy for dental ceramic crown, 4 types of mixtures(A, B, C, D) with old and new metal wereprepared for cyclic casting. The results of cyclic casting can be outlined as follows: 1. For Vickers hardness after casting, specimen A and D tended to have lower hardness in thecourse of cyclic casting, while specimen B and C tended to higher hardness. 2. The results of X-ray diffraction analysis showed that major crystal phase contained nickel-chrome compounds and carbide. 3. The observation results of SEM photographs after cyclic casting show that there was asignificant tendency to have similar structures among experimental groups. 4. The results of EDX analysis after cyclic casting showed that there were little differences inchemical composition between parent metal and base metal alloy.Although industrial nickel-chrome cast alloy did not show any significant change in materialproperties even through cyclic casting over several times, it is recommended that more there bemore in-depth studies on how to detect any potential corrosion, discoloration and toxication ofdental ceramic crown implanted in patient's oral cavity.

치과주조용 비귀금속 합금의 금속 용출 수준

사공준,박수철,Sakong, Joon,Park, Soo-Chul 대한치과기공학회 2013 대한치과기공학회지 Vol.35 No.1

Purpose: This study was to assess the extents of the release of metals from the non-precious alloys used for dental casting by measuring the differences in the extents of the release of metals by types of alloys, pH level and elapsed time. Methods: Uniform-sized specimens(10 each) were prepared according to the Medical Device Standard of the Korea Food and Drug Administration(2010) and International Standard Organization(ISO22674, 2006), using four types of alloys(one type of Ni-Cr and one type of Co-Cr used for fixed prosthesis, and one type of Ni-Cr and one type of Co-Cr used for removable prosthesis). A total of 12 metal-release tests were performed at one-day, three-day, and two-week intervals, for up to 20 weeks. The metal ions were quantified using an Inductively Coupled Plasma-Atomic Emission Spectrometer. Results: The results showed that the extent of corrosion was higher in the ascending order of Jdium-$100^{(R)}$, Bellabond-$Plus^{(R)}$, Starloy-$C^{(R)}$, and Biosil-$F^{(R)}$. The lower the pH and the longer the elapsed time were, the greater the increase in metal corrosion. At pH 2.4, the release of Ni from Jdium-$100^{(R)}$, a Ni-Cr alloy, was up to 15 times greater than the release of Co from the Co-Cr alloy from two weeks over time, indicating that the Ni-Cr alloy is more susceptible to corrosion than the Co-Cr alloy. Conclusion: It is recommended that Co-Cr alloy, which is highly resistant to corrosion, be used for making dental prosthesis with a non-precious alloy for dental casting, and that non-precious alloy prosthesis be designed in such a way as to minimize the area of its oral exposure. For patients with non-precious alloy prostheses, a test of the presence or absence of periodontal tissue inflammation or allergic reaction around the prosthesis should be performed via regular examination, and education on the good management of the prosthesis is needed.

치과 주조용 금합금에서 정상인 치은 섬유모세포의 세포 독성 연구

한창수,천재식 대한구강악안면병리학회 2005 대한구강악안면병리학회지 Vol.29 No.4

The aim of this study was to investigate the cytotoxicity of dental casting gold alloys. Recently, "biocompatability" is considered the most important requirement of dental materials. Dental metals and alloys were estimated by quantity of released ions, which had influenced to living tissues. The requirement of using normal human cells for cytoxicity strudy were abruptly increased. We used the cultured normal human gingival fibroblasts to estimate the cytotoxicity of dental casting gold alloys. The product of S company(Korea, AIGIS-SOFT, AIGIS-PLUS, AIGIS-A, AIGIS-PT, experimental group) and D company's (German, Biocclus inlay, Biolor SG, Stabilor NF Ⅳ, Degulor B, control group) dental casting gold alloys were used. The morphological investigation, hemolysis test, MTT assay and SRB assay were done in vitro. In vivo, inflammatory reaction in rat was examined for 2 weeks. 1. In the result of cytotoxicity assay, there were some differences but was no significancy among the results between two group's hemolysis, MTT and SRB assay. 2. The gingival fibroblasts attached to the surface of dental casting gold alloy showed various features and increased in number as the time had passed. 3. In vivo, chronic inflammatory cell infiltration was prominent from 3 days to 1 week and inflammation was reduced as time had gone. From the aboving results, there were no significant differences in cytoxicity depending on the ratio of gold content, but showed differences depending on the ratio of total precious and non-precious metal content between two groups. In vitro study showed few differences in inflamation reaction.

치과주조용 Ag-Pd-Zn-Sn-In 합금의 시효경화 특성

이재호,김명진,이희경,김형일,설효정 大韓齒科器材學會 2004 대한치과재료학회지 Vol.31 No.1

Cu가 첨가되어 있지 않고, 대신에 상대적으로 많은 양의 Zn 그리고 소량의 Sn과 In이 첨가된 치과주조용 Ag-Pd-Zn-Sn-In 합금의 시효경화 특성을 경도 시험, X선회절 실험, 주사전자현미경 관찰, 전자탐침 미소분석법으로 조사하여, 다음과 같은 결과를 얻었다. 1. 950℃에서 용체화처리된 시편을 500℃와 550℃에서 등온시효처리하면, 시효 초기에 경도가 완만히 상승하여 최고 경도에 도달하였고 최고 경도를 일정 기간 유지하고 나서 서서히 하강하였다. 2. 용체화처리된 시편은 Pd 원자가 고용된 Ag-rich α1상, Pd3Sn인 α2상, Pd2Zn인 α3상의 3상 공존이었고, 등온시효처리함에 따라 Ag-rich α1상에서 Pd-rich 상으로 추정되는 β상이 석출하였다. 3. 시효 초기의 경화는 Ag-rich 기지에서 Pd-rich 상의 석출로 인한 격자변형에 기인하는 것으로 추정된다. 4. 시효처리 시간을 연장함에 따른 과시효 연화는 입계에 Ag-rich α1상과 Pd-rich β상으로 된 층상조직의 석출과 조대화에 기인하였다. 5. Pd3Sn인 α2상과 Pd2Zn인 α3상은 시효경화에 기여하지 않았다. Age-hardening characteristics of a dental casting Ag-Pd-Zn-Sn-In alloy without copper (52.0 wt% Ag - 39.9 wt% Pd - 4.0 wt% Zn - 2.0 wt% Sn - 2.0 wt% In - 0.1 wt% Ir) was investigated by means of hardness test, X-ray diffraction study, scanning electron microscopic observations and electron probe microanalysis. The specimen solution-treated at 950℃ was three phases of the Ag-rich α1 phase containing Pd element, the α2 phase based on Pd3Sn and the α3 phase based on Pd2Zn, and the Pd-rich β phase was precipitated from the Ag-rich α1 phase by the isothermal ageing,. The initial hardening seemed to be attributed to coherency strains which were formed in the Ag-rich matrix by the precipitation of Pd-rich phase. Overageing with softening was due to the formation and coarsening of the lamella precipitates at grain boundaries, which were composed of the Ag-rich α1 and Pd-rich β phases. The α2 phase based on Pd3Sn and the α3 phase based on Pd2Zn did not contribute to the age-hardening of this alloy.

수종 치과용 합금의 세포독성 평가에 관한 연구

윤숙진,김철위 大韓齒科器材學會 1992 대한치과재료학회지 Vol.19 No.2

The restorations with dental alloys have toxic as well as mechanical stimulation to gingival tissue when they were contacted for long time. Cell culture method is one of the tests for evaluation of biocompatibility of the material or its components. In this study, the cytotoxicity of type Ⅲ dental crown and bridge casting alloys, dental amalgams, dental amalgam alloy containing metals, and copper-alluminum alloys was evaluated. L 929 cells were cultured in Eagle's MEM supplemented with 10% fetal bovine serum, 100 IU/㎖ of penicillin, and 100 ㎍/㎖ of streptomycin and seeded with ?? cells/㎖ in plastic dishes (100×15㎜). After the cell monolayer had formed, medium was removed and the medium containing agarose was added. The cells were stained with 0.01% neutral red solution and the specimens were placed on the agar. After incubation for 24 hours at 37℃ in the CO₂incubator, the cultures were examined macroscopically and microscopically under a microscope to determine the cytotoxicity. From the experiments, the following results were obtained : 1. Type Ⅲ dental crown and bridge casting alloys, dental ceramic alloys, dental Co-Cr alloys, pure silver, and pure tin showed mild cytotoxicity with zone index of 1.0-1.5 and lysis index of 1.0-2.0. 2. Copper-based alloys (NPG), after ethylene oxide gas sterilization, showed mild cytotoxicity with response index of 1.0/2.0 ; after autoclave sterilization, showed moderate cytotoxicity with response index of 2.0/3.0. 3. Dental high copper amalgam (HVA) showed moderate cytotoxicity with response index of 2.0/3.0. 4. Of the constituent metals of dental amalgam alloy, copper showed severe cytotoxicity with response index of 4.0/4.5, and zinc showed moderate cytotoxicity with response index of 3.0/3.3.

치관 보철물 제작에 사용되는 치과용 금속의 변연 적합도 비교

김남중,황경숙,박용덕 대한치과기공학회 2003 대한치과기공학회지 Vol.25 No.1

This study was aimed to verify a comparison by dental alloys upon the marginal fitness of dentalprosthesis. Firstly, we waxed up on 45 epoxy resin dies, pressed the margin with hands, andidentified the marginal fitness with microscope. And we made a single direct spruing system typeof sprue by 3 dental alloys - metal crown alloys, PFM crown alloys, and gold crown alloys - each15, total 45 waxing up, adjusting W/P ratio and invested the cast ring. Then, we made the dentalprosthesis using the electric casting machine. In these processes we followed the manufacturer'sinstructions, in order to maintain the other conditions from the inner and outer, which includedinvestment and burning out. After we tried on the dental prosthesis on epoxy resin dies, we havegot the means of marginal gap at 9 points with same distances, around the cervical line which waschecked already, using microscope(300). The results of this study were as follows :1. Metal crown alloys showed 2.9% better in marginal fitness than PFM crown alloys, and thedifference was not statistically significant(P=0.497). 2. Gold crown alloys showed 31.3% better in marginal fitness than Metal crown alloys, and thedifference was statistically significant(P=0.004).3. Gold crown alloys showed 32.4% better in marginal fitness than PFM crown alloys, and thedifference was statistically significant(P=0.002).4. We saw that Gold crown alloys was the best dental alloys in the marginal fitness among thethree.(P=0.049).

수종치과용 금합금에서 정상인 조골세포의 생체적합성 연구

장영익,천재식,오충훈 대한구강악안면병리학회 2006 대한구강악안면병리학회지 Vol.30 No.2

Since ancient Eygypt, various dental materials were used for lost teeth including gold. The key point of this materials were nontoxic to human body. Since early of 1990's, dental implant was done for recovery of maxillofacial defects. From middle of 1970's, osseointergation concept of implant was introduced and performed in dental field. Biocompatibility of titanium showed good effect for osseointergration but had some problems (Galvance current and toxic corrosion) with suprastructures such as gold crowns. This study was performed to make safe dental implants which have reduced Galvanic currents and corrosion. 3 kind of dental casting gold alloys (different Gold contents, 1㎝×1㎝×0.1㎝ plates.) were used as experimental group, while Titanium were used as control group. Normal human osteoblasts(NHOsts)were cultured during 1-4weeks for histologic study. For analysing the calcium(Ca), Phosphorus(P) and alkaline phosphatase(ALP), NHosts were cultred during 2-23days. After experiments, histologic finding were observed by LSM and SEM. Ca, P, ALP concentration by automatic biochemical analyzer were analyzed by ANOVA test and linear regression method. The results were as follows. Biocompatibility of dental casting gold alloys were similar to titianium alloys histolgically. Biochemical analysis of dental casting gold alloys had no significant difference to titianium alloy except AIGIS-Fine. We could conclude that biocompatibility of dental casting gold alloys with high contents of gold were superior to that of low contents and alloys with high contents of gold had no significant difference from titanium on NHost culture. Gold dental implant might be better than titanium implant due to similar biocompatibility and no galvanic currency.