치과용 저채도, 고투명도 콤포짓트레진의 색상특성에 관한 연구

이용근,임범순,김철위 대한치과기재학회 2001 대한치과재료학회지 Vol.28 No.1

최근 개발된 저채도 및 고투명도 색상의 콤포짓트레진을 대상으로 미중합 상태, 중합후 및 열순환 후의 색상을 측정하여 중합 과정과 열순환 후의 변색도를 기존 색상의 콤포짓트레진과 비교하였고, Vita 색조가이드 및 Bioform 색조가이드의 색상과의 관계를 보았다. 또한 색측정 방법 및 색상을 측정할 때 사용하는 표준광원의 종류에 따른 색상의 차이를 분석하였다. 2종의 콤포짓트레진을 대상으로 분광광도계(CM-3500d, Minolta, Japan) 로 정반사광 제거방식 (SCE) 및 정반사광 포함방식 (SCI) 등 두 종의 측정방법과 색상측정용 광원으로 표준광원 C, A 및 D65 를 이용하여 색상을 측정하였다. 시편의 열순환은 5~55 ℃에서 3,000 회 실시하였다. 색조가이드의 색상은 색조 탭의 순면을 2,400 번까지 사포로 연마하여 분광광도계의 측정광의 직경인 3mm 이상의 평평한 면을 만든 후 측정한 바, 다음과 같은 결과를 얻었다. 1.표준광원의 차이에 의한 색차(ΔE*)는 저채도 색상이 기존 색상의 콤포짓트레진보다 중합전, 중합후 및 열순환 후 조건에서 모두 크게 나타났으며, 표준광원 A는 C와 D65 와 차이가 큰 것으로 나타났다. 또한 SCE 방식과 SCI 방식으로 측정한 색차는 유사하였다. 2.중합전과 중합후의 색차 및 열순환 후의 변색도는 저채도 색상군의 경우가 표준광원의 종류와 무관하게 기존 색상군의 콤포짓트레진보다 유의하게 높았으며 (p〈0.05), SCE 방식으로 측정한 색차는 SCI 방식으로 측정한 색차보다 높았다. 3.색조가이드의 색좌표중 CIE L*과 CIE b* 는 표준광원 A로 측정한 값은 다른 광원을 사용하였을 때보다 높았고, CIE a* 는 표준광원 A와 D65로 측정한 값이 C로 측정한 경우보다 높았다. 4.Vita 색조가이드의 색상계열(A, B, C, D)은 SCE 방식으로 측정한 L* 값 및 a* 값과 음의 상관관계가 있었으며 다중회귀계수는 0.87이었다. 또한 Chromascop 색조가이드의 색상계열 (100, 200 등) 은 SCI 방식으로 측정한 L* 값과 음의 상관관계를 보였다. 5.저채도 및 고투명도 색상을 포함하는 체계적인 색조가이드의 개발이 필요하다.

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.

광원 및 광조사 방법에 따른 심미충전재의 중합수축

이용근,윤태호,임범순,김철위 대한치과기재학회 2000 대한치과재료학회지 Vol.27 No.4

The polymerization shrinkage of dental esthetic filling materials of five kinds of resin composite and three kinds of compomer was measured with a thermal dilatometer (Thermal Dilatometer, DIL 402C, TASC 414/3A Controller, Netzche, Germany) during polymerization with a halogen lamp curing unit (VIP, Bisco, U.S.A.) or a plasma arc curing unit (Flipo, Serial No. P03G02221, Lokki, France). The irradiation time of the halogen lamp was 40, 80 and 120 s with the intensity of 400 ㎽/㎠, and that of the plasma arc was 9 s. The pulse-cure mode with a halogen lamp was 5 s pre-polymerization at 200 ㎽/㎠, 3 minutes wait and then 120 s irradiation at 400 ㎽/㎠. From this experiment, the following results were obtained : 1.Depending on the irradiation source and mode, the amount of polymerization shrinkage after 14 minutes from the start of irradiation was significantly different in some materials. However, there was no significant difference in most of materials (p>0.05). 2.Most of the polymerization shrinkage occurred within two minutes from the start of irradiation except for pulse-cure. 3.In all the materials studied, the amount of polymerization shrinkage after 14 minutes from the start of irradiation was not different between the results from 120 seconds irradiation with the halogen lamp and these from pulse-cure (p> 0.05), and the amounts of shrinkage from a plasma arc was generally lower than those from other curing modes. 4.The amount of polymerization shrinkage after 14 minutes from the start of irradiation was not different between the results from 120 seconds irradiation with a halogen lamp and those from plasma arc (p>0.05) in all the eight materials studied.

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 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).

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.

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.

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.

군 사회복지에 대한 이해와 발전방안 : 제대군인 노후복지를 중심으로

이근범 원광대학교 대학원 2008 論文集 Vol.41 No.-

Since the republic of Korea is one of the OECD members, Korea will be joined into a part of advanced countries in a soon. Also, in the 21st century, we are faced a society which is based informational intelligent; therefore, a government of korea now guarantees basic lives to the members of the nation and efforts to execute various matters of the social security system for the lives of human being. It could be possibly happened that growth of economy and extension of the social security system because the republic of Korea had an army which has put its all efforts to security of the nation. As mentioned before, the army is a core constituent for the nation's existence and protection. As a result, in this research, it presents a development plan that can improve lives value of professional officers to make them accomplish their main duties which is national defense. Specially, it also presents a welfare plan for old age people to prepare an aging society, and through the plan, it can stimulate reserve officers' and potential reserve officers'. Consequently, it will ultimately contributes to enforce the national defense power for the development of the republic of Korea.

레진기질과 생체활성 필러에 따른 콤포짓트레진의 특성

이용근,임범순,김철위 大韓齒科器材學會 2003 대한치과재료학회지 Vol.30 No.2

In dentistry, since composite resins are used to restore teeth, their chemical and physico-mechanical characteristics should be similar to those of natural tooth. The mineral phase of bone and teeth is mainly hydroxyapatite. Therefore, synthetic hydroxyapatite would seem a good choice as an inorganic filler to he used in dental restoration or bone implant. The purpose of this study was to gain more insight into the possibility of the bioactive filler incorporated composite resin as restorative material, limns; material or pulp capping material through the evaluation of mechanical properties and cytotoxicity. Bioactive fillers such as apatite-wollastonite (AW) glass ceramic, bioglass (BG) and hydroxyapatite (HA) powders, and conventional glass fillers were incorporated into light-curing resin matrices composed of Bis-GMA and TEGDMA (6:4 by wt.), Bis-GMA and HEMA (6:4 by wt.), Bis-GMA, HEMA and TEGDMA (3:4:3 by wt.). and UDMA and TEGDMA (6:4 by wt.). Compressive, diametral tensile and flexural strength of light-cured specimens immersed in 37℃ DW for 24 hours was measured. Cytotoxicity by MTT method was also evaluated. When Bis-GMA and TEGDMA mixture was used as the resin matrix, compressive, diametral tensile and flexural strength of bioactive filler incorporated composite resin was 17.72∼128.22 ㎫. 39.57∼84.46 ㎫ and 21.35∼57.36 ㎫, respectively. When Bis-GMA and HEMA mixture was used as the resin matrix, BG filler incorporated composite resin did not cure, and the highest compressive and diametral tensile strength of bioactive filler incorporated composite resins was 40.24 ㎫ and 35.30 ㎫, respectively. When Bis-GMA, HEMA and TEGDMA mixture was used as the resin matrix, BG filler incorporated composite resin did not cure, and three strength values were highest after incorporating HA filler. When UDMA and TEGDMA mixture was used as the resin matrix, compressive, diametral tensile and flexural strength of bioactive filler incorporated composite resin was 38.61∼137.31 ㎫, 32.59∼110.47 ㎫ and 17.10∼48.70 ㎫, respectively. Generally, cytotoxicity of bioactive filler incorporated composite resin was higher than those of conventional glass filler incorporated resins. From the above result, mechanical properties of bioactive filler incorporated composite resins made of conventional Bis-GMA, UDMA and TEGDMA matrices were moderate; however, those of HEMA-incorporated matrices were low.