치과용 합금의 부식성에 관한 연구

임범순,이용근,윤숙진,김철위 大韓齒科器材學會 1995 대한치과재료학회지 Vol.22 No.1

Corrosion of dental alloys in the oral cavity can affect the mechanical, esthetic properties and efficiency of metallic restorations, and has great influence upon the local and systemic health of patients. The purpose of this study was to clarify the corrosion behavior of various dental alloys, and to measure the galvanic currents between dissimilar alloys. Fifty-eight kinds of dental casting alloys such as twenty-nine high gold alloys, ten low gold alloys, fourteen silver-palladium alloys, five base metal alloys, and twenty kinds of ceramic alloys such as seventeen noble metal alloys, three base metal alloys, were used as the experimental alloys. Modified Fusayama's artificial saliva titrated to pH 6.7 with phosphoric acid was used as an electrolyte. The specimens were immersed in the modified artificial saliva of 37℃. The rest potentials, anodic polarization curves, corrosion potentials, and galvanic currents were measured by using the potentiostat / galvanostat and zero shunt ammeter. From the experiment, the following results were obtained : 1) The gold based alloys showed the high rest potentials and the low current densities within experimental potential range. 2) The rest potentials and the current densities of the palladium-based alloys were influenced by the content of platinum, palladium, and silver. 3) In the nickel-chromium base alloys, the formations of passivation film were influenced by chromium content. The copper-aluminum alloy showed very high current density which was more than 150 mV . 4) The corrosion potentials of ceramic alloys were lower than those of dental casting alloys, but the trend of anodic polarizations were generally similar to the other alloys. 5) The amount of galvanic current and the polarity in the bimetallic galvanic cell could not be predicted considering only the alloy composition. The galvanic current decreased while the measuring time passed, but flew continuously.

간세포암의 크기와 알파 피토프로틴의 연관성

임효순,정용연,김재규,윤웅,강형근,박진균 全南大醫大 2001 전남의대학술지 Vol.37 No.4

치과용 콤포짓트 레진의 중합수축 응력

임범순,이용근,김철위 대한치과기재학회 2001 대한치과재료학회지 Vol.28 No.2

치과용 콤포짓트 레진의 적정중합을 위한 최소 광조사 시간 평가

임범순,이용근,김철위,최기열,이중배 大韓齒科器材學會 2004 대한치과재료학회지 Vol.31 No.1

The aim of this study was to estimate the minimum irradiation time for dental composites using a dynamic mechanical analyzer (DMA) and FT-IR. Six commercially available dental composites with A3 shade were tested: Heliomolar RO (Vivadent, Liechtenstein), Charisma (Kulzer, Germany), Herculite XRV Enamel (Kerr, USA), Aelitefil (Bisco, USA), Z100 (3M, USA), and Z250 (3M, USA). Storage modulus was measured by using DMA (StressTech Rheometer, Rheologica Instrument, Sweden) with fast oscillation mode (1 Hz). After disk-type (4 ㎜ ?1 ㎜) samples were irradiated with 500 mW/cm2 for 1, 2, 3, 4, 5, 10, 15, 20, and 30 s, storage modulus was recorded continuously for 60 min. Degree of conversion was also measured using FT-IR spectroscopy (FTS-165, Biorad Win-IR, Perkin-Elmer, USA) at 60 min after irradiation with same curing condition as DMA test. Sample irradiated with 500 mW/cm2 for 120 s was used as a control. The average of results for five specimens was compared using Tukey multiple comparison test (p=0.05) and the minimum irradiation time of composites was determined. The minimum irradiation time to get adequate polymerization was different depending on the dental composites. Both Z100 and Z250 require short irradiation times (5 s) and Charisma requires long irradiation time (15 s).

티타늄 표면처리에 따른 조골세포의 반응

임영준,이용근,임범순,김철위 大韓齒科器材學會 2004 대한치과재료학회지 Vol.31 No.1

It is well known that surface modification of titanium for implant has been shown to improve the adhesion, migration and differentiation of adjacent cells and tissues. This study presented the results of an experimental study on the interaction between MC3T3-E1 (mouse calvarian osteoblast cell line) cells and cp-titanium treated by thermal oxidation at four different temperatures after TiO2 blasting and NaOH treatment, which could provide the benefits of surface roughening and favorable oxide layer formation. No heat treatment group was used as a control. Cell interactions were studied using the combination of phase contrast microscope and scanning electron microscope. Potential cytotoxicity was tested by MTT assay. The response of osteoblast cells was different according to the condition of surface modifications. Thermal oxidation at 600℃ showed the best early cell attachment and calcium nodule formation compared to other groups. Thermal oxidation at 800℃ showed the worst cell attachment and proliferation. In general, osteoblast cells were attached to accompanying the formation of cellular process, spreaded and differentiated on the specimen surfaces. Calcium nodules were formed on the surface after these cells were developed multiple cell layers. These early osetoblast/titanium interactions might play a critical role in the osteoinduction stage of osseointegration. There was no statistically significant difference in cytotoxicity among the heat treated surfaces from the MTT assay(p>0.05). The results of microstructure analysis of the characterized cp-titanium surface of this study will be published separately.

관상동맥질환의 중증도와 혈중지질치 및 아포지단백과의 상관관계

임현주,황종현,류재근,정병천,조용근,채성철,전재은,박의현 慶北大學校 醫科大學 1997 慶北醫大誌 Vol.38 No.1

목적 : 관상동맥질환의 위험인자로서 혈청지질 및 혈장 지단백에 대한 관심이 높아지고 있고 또 아포지단백이 관상동맥 질환을 일으키는데 다른 지질보다 더 중요하다는 연구가 많이 발표되고 있으나 우리나라에서는 아포지단백에 대한 연구가 그리 많지 않은 편이다. 이에 저자등은 혈중지질치와 새로운 위험인자로 알려지고 있는 아포지단백치를 측정하고 이들과 관상동맥질환 중증도와의 상관 관계를 알아보았다. 대상 및 방법 : 관상동맥질환이 의심되어 관상동맥조영술을 실시한 69명의 환자를 대상으로 하였으며 12시간 이상 공복후 혈청을 채취하여 총콜레스테롤, 중성지방, HDL-콜레스테롤, 아포지단백 AI (ape AI), 아포지단백 B (ape B)를 측정하였다. 관상동맥조영상 50%이상의 협착이 있는 혈관의 수 (lesion number), 최대협착을 합한 값 (lesion score), 각 분절의 최대협착을 합한 값 (total score), 가장 심한 협착 값 (peak stenosis) 등으로 관상동맥 중증도를 알아본 다음 이들과 혈청지질치, 아포지단백과의 상관 관계를 비교해 보았다. 상관 관계는 Spearman's correlation coefficient를 구하였다. 결과 : 관상동맥질환의 중증도와 각 지질치 간의 상관 관계를 비교해 보았을때 lesion number와 관계있는 것은 연령 (r=0.2789), 중성지방치 (r=0.2829)이며 lesion score와 관계있는 것은 연령(r=0.2911), 중성지방치0 (r=0.3316), 총콜레스테롤과 HDL-콜레스테롤의 비 (r=0.2361), apo B 치(r=0.2759), apo AI과 apo B의 비 (-0.3154)로 나타났다. Total score는 연령 (r=0.3100), 총콜레스테롤치 (r=0.2452), 중성지방치 (r=0.3022), 총콜레스테롤과 HDL-콜레스테롤의 비 (r=0.2770), apo B치 (r=0.2927), apo AI과 apo B의 비 (r=-0.3408)와 연관이 있었고 peak stenosis는 중성지방 치(r=0.3305), ape B 치 (r=0.2968), apo AI과 apo B의 비 (r=-0.3977)와 관계가 있었다. 연령으로 조정하여 partial correlation을 좌면, 관상동맥조영술상 중증도는 중성지방치 (r=0.3408), apo B 치(r=0.2877), apo AI과 apo B의 비 (r=-0.3460)와 유의한 상관 관계가 있었다. 이중 ape AI과 ape B의 비는 lesion score (r=-0.2640), total score (r=-0.3057), peak stenosis (r=-0.3460)와 유의한 상관관계를 보였다. 결론 : 이상의 결과로 보아 apo B치 그리고 apo AI과 apo B의 비가 관상동맥 중증도의 예견인자로 다른 혈중 지질 치보다 더 유용하다는 것을 알 수 있었다. Objectives : Recently, it was reported that the measurements of apolipoprotein levels may be valuable in the clinical assessment of coronary artery disease severity. However there are a few reports regarding to the relationship between coronary artery disease severity and apolipoprotein levels in Korea. Thus, we measured serum lipid and apolipoprotein levels and studied the relationship between coronary artery disease severity and serum lipids and apolipoproteins levels. Subjects and Methods : The 69 patients who underwent coronary angiography to evaluate chest pain were subjected to this study. We measured the levels of serum cholesterol, triglycerides, HDL cholesterol, apolipoprotein AI(apo AI) and apolipoprotein B(Apo B) and measured the severity of coronary artery disease by lesion number, lesion score, total score and peak stenosis. Then, we studied the relationship between coronary artery disease severity and apolipoproteins and calculated the correlation coefficient. Results : The results were as follows. There are significant correlation(r=0.3) between age, triglycerides, apo B levels, apo AI/B ratio and coronary artery disease severity. In controlling for age, tyiglycerides, apo B levels and apo AI/B ratio shows significant correlation(r=0.3) with coronary artery disease severity. Especially, apo AI/B ratio shows significant correlation(r=0.3) with lesion number, total score and peak stenosis. Conclusion : These results suggest that the apo B levels and the ratio of apo AI/B can be used as significant independent predictor for coronary artery disease severity rather than other serum lipid levels.

배양조건에 따른 치수세포 RPC-C2A의 특성 : 배양용기 및 BMP 처리 Culture Ware and BMP Treatment

이용근,임범순,김철위 大韓齒科器材學會 2003 대한치과재료학회지 Vol.30 No.4

Odontoblasts are highly differentiated cells aligned at the periphery of the dental pulp. Pulp tissue responds to injury by generating reparative dentine elaborrated by odontoblast-like cells that differentiated from pulp cells. In vitro, dental pulp cells cultured under certain conditions are able to express typical markers of cell differentiation; however, no culture sysem can simulates clinical pulp response. The purpose of this study was to evaluate the effect of culture ware and BMP on the seeding. growth sne differentiation of pulp derived cell line, RPC-C2A. Large pore-sized PET membrane (0.4 ㎛, Cell Culture Insert, BD Science, USA), rhBMP-4 (R & D Systems, USA) and polystyrene modified by vacuum-gas plasma treated culture surface (Primaria, BD Science, USA) were tested. RPC-C2A cells are maxillary incisor pulp cells from male Wistar rats (Kasugai el al., 1988). Cells were cultured on a traditional polystyrene culture ware (PS), transparent PET membrane (MI), Insert + rhBMP-4 (20 ng/ml, MB), and Primaria culture ware (PM) up to 21 days. Culture media was 10% FBS added DMEM with 10 mM β-glycerophosphate, 10^-8 M dexamethasone, 50 ㎍/ml ascorbic acid and 50 mM sodium fluoride. Formation of multilayered cell layer and mineral nodule was determined with a phase contrast microscope and EDXA. There were no differences in cell attachment and growth rate among four culture conditions up to three-days culture. Multilayered cells were observed after six-days culture, and mineral nodules were observed in MB condition after seven-days culture. After nine-days culture, mineral nodules were observed in PS, and new nucleation of mineral nodules was prominest in MI and MB conditions. Exfoliation of cells from the dish was observed in PS after 13-days culture, and vaeuoles were formed in MI after 19-days culture. After 21-days culture, cell death was accompanied by increase of mineral nodules in MB. Growth and development of pulp cells were influenced by the culture ware and BMP. In MB condition, the duration for the formation of multilayered cells and mineral nodule was shortened compared to other conditions.

치과용 알지네이트 인상재의 국산화 및 개량에 관한 연구 : Ⅱ. 불소 화합물 첨가 후 특성 변화 Part Ⅱ. The Effects of Fluoride Incorporation on the Properties

이용근,임범순,김철위 大韓齒科器材學會 2002 대한치과재료학회지 Vol.29 No.3

The goal of this study was to develop dental alginate impression materials that is proper for domestic usage conditions. After incorporation of additional techniques into this material to make multifunctional impression materials, this final product can be commercialized. In the first year of this study, although the characteristics were different by the viscosity of sodium alginate, two formula for dental alginate impression materials were determined, which contain sodium alginate, calcium sulfate, diatomaceous earth, borax, magnesium oxide, potassium chloride, sodium acetate, sodium phosphate, zinc fluoride and zinc oxide (WM₃, WM₄, WH₃ WH₄). New technique tried in the second year was the fluoride incorporation to deliver fluoride on the tooth surface during impression procedure. Four methods of fluoride incorporation were tested. Materials were mixed with distilled water, or 100-ppm fluoride solution. 1 or 2% sodium fluoride, or 1% stannous fluoride was incorporated into the powder. The fluoride-containing materials were mixed with distilled water. Fluoride release, compressive strength, elastic modulus, flexibility, recovery form deformation and setting time were determined. As the results, fluoride release was increased after incorporation of fluoride into water or materials, and the released amount was 0.762~14.76ppm. Sodium fluoride or stannous fluoride incorporation resulted in higher fluoride release than the control group (p<0.05). Incorporation of fluoride into alginate impression materials may be efficient in releasing fluoride without having any deleterious effect on the properties of material. Additional study on the method that can enhance the compatibility with gypsum products was performed. All compositions reproduced 50 ㎛ line for 25 ㎜, and immersion of impression into a 2% potassium chloride solution resulted in better surface quality. From the results, these compositions can be used to make commercial dental alginate impression material, however development of additional commercialization procedure is needed. Domestic sodium alginate should be developed to down the price of ingredient materials.

치과용 알지네이트 인상재의 국산화 및 개량에 관한 연구 : Ⅰ. 조성이 특성에 주는 영향

이용근,임범순,김철위 대한치과기재학회 2001 대한치과재료학회지 Vol.28 No.3

Dental alginate impression materials have become widely used to take study impression for orthodontic and other purposes and, to a limited extent, have been applied in inlay, crown and bridge procedures. The alginate impression products have good elastic properties and compare well with the agar materials. The final purpose of this serial study is to develop a domestic dental alginate impression material which is proper for use in Korea. The final purpose of this first year study was to find a proper composition of alginate impression material, which shows appropriate mechanical properties and high biocompatibility. Several kinds of experimental alginate impression materials were prepared by mixing sodium alginate, calcium sulfate dihydrate, diatomaceous earth as filler, borax, magnesium oxide, potassium chloride, sodium acetate, sodium phosphate, zinc fluoride and zinc oxide in varied proportions. Texture of powder and mixture, flexibility, recovery from deformation, setting time, compressive properties, compatibility with dental stone, reproduction of detail and cytotoxicity by MTT assay and neutral red inhibition zone of mixed experimental and commercial alginate impression materials were tested according to the specifications of Korean Food and Drug Administration, Korean Dental Association No. 8, American Dental Association No. 18 and International Standardization Organization 1563 (1990). From this study, proper compositions of experimental alginate impression material which showed flexibility of 5∼20% (in accordance with the specification), and proper setting time of 1.5∼5 minutes was found. Although the property of recovery from deformation was lower than that of the specification, these values were similar to those of commercial alginate impression materials. The compressive strength was in accordance with the specification of more than 0.35 Mpa. Some compositions showed proper detail reproduction. Cytotoxicity was not different regardless of the composition, and was similar to those of commercial materials. From the above results, two promising compositions were determined to be used as the basic composition for making a domestic alginate impression material. On this result, beneficial properties of fluoride release, reduced dust production and sufficient antibacterial effect will be added before marketing.

광도 및 광원 차이가 치과용 광중합 콤포짓트레진의 중합깊이에 주는 영향

이용근,임범순,김철위 대한치과기재학회 2001 대한치과재료학회지 Vol.28 No.2

Inadequately polymerized resin has greater water sorption and solubility, possibly manifested clinically with early color instability and degradation. The purpose of this study was to determine the influence of total light energy (light intensity X irradiation time) of halogen and plasma arc curing units on the polymerization deth of five universal resin composites by measuring the Vickers hardness number (VHN/0.1, 10) at the surface and 0.5, 1.0, 1.5, 2.0, 2.5and 3.0㎜ under the surface. The total light energy for the halogen light curing unit (VIP, Bisco, U.S.A.) was 4,000, 8,000, 16,000 mJ/㎠, and VHN was measured immediately after curing and after 24-hours storage in 37℃ distilled water. Polymerization behavior of plasma arc curing unit (Flipo, Serial No. P03G02221, Lokki, France) was also determined, and the irradiation time was 3 and 9 seconds. From this experiment, the following results were obtained. 1.VHN immediately after light curing was 33.2∼123.3, and showed a great variation depending on the brand of the materials. The curing depth was different depending on the brand of the materials by the variables of light source, total light energy and light intensity. 2.VHN after 24 hours was 36.3∼115.1, and in almost all cases, these values increased in comparison to those immediately after light curing. However, when the total light energy was absolutely insfficient for curing, these values decreased. 3.When the same total light energy was irradiated with different light intensity, the differences in curing depth and VHN were depended on the brand of the materials. 4.In some brand of the materials, the curing depth and VHN were similar regardless of the light source (halogen or plasma arc) when the total light energy was the same.