은, 동 및 팔라듐이 치과용 저금계 합금 및 은-팔라듐계 합금의 표면경도, 황이온에 의한 변색 및 부식저항성에 주는 영향 : Ⅱ.Experimental Low Gold Based Alloys Ⅱ. 실험용 치과용 저금계 합금

임범순,문현정,김철위 대한치과기재학회 1999 대한치과재료학회지 Vol.26 No.2

Nine experimental low gold based alloys (Au = 20 %) were prepared with various concentrations of Pd, Ag, and Cu. Experimental alloys were divided into three groups : casted alloys, quenched alloys subsequent to solution treatment, and aged alloys subsequent to solution treatment. Microstructure of alloys was examined by Optical microscope and SEM with EDXA, and surface hardness of alloys was measured by Vickers' hardness tester. Color changes and anodic polarization curves of alloys in the modified Fusayama's artificial saliva with various S² concentrations (0.01, 0.10, 0.50, 1.00, and 5.00 mM/ℓ) were evaluated by Spectrophotometer and Potentiostat. With an increase of Pd concentration in experimental alloys, color change (ΔE) of alloys was significantly decreased and surface hardness was moderately increased, but it had surprisingly little effect on the anodic polarization curves (p>0.05). Color change (ΔE) and surface hardness were increased with a decrease of Ag/Cu ratio in experimental alloys, but anodic polarization curves did not change significantly (p>0.05). Color changes of the quenched alloys was lower than those of the aged alloys. Corrosion potential of alloys was not affected by heat treatments, but current densities were affected at high potential (>400 mVSCE). Significantly higher current density of the aged alloys, compared to the quenched alloys, could result in server corrosion. The surface hardness of the casted alloys was apparently greater than that of quenched alloys. In SEM and EDXA analysis, it was observed that Pd was precipitated in the Cu-rich phase and Au migrated to the Ag-rich phase.

모 대학병원 입원환자의 직업력 기록에 관한 조사

임현술,김지용,정철 동국대학교 경주대학 1998 東國論集 Vol.17 No.2

From January 9, to January 27, 1996, we surveyed medical records for the occupational history of 352 admitted patients in university hospital located in Pohang city. Also, we interviewed the study subjects about their occupational histories to search for occupational related cases. The results obtained are as follows. The number of males were 205 cases and the number of females were 147 cases. The age and sex distributions of study subjects were not significant (p>0.05). Internal medicine (50.3%), orthopaedics (19.6%), general surgery (8.8%), neurosurgery (5.7%) and obstetrics & gynecology (3.7%) were the major admitted departments of the study subjects. The records of occupational history by doctors were only 9 cases (2.6%) but by nurses were 197 cases (56.0%). And then, there were no detailed descriptions for occupations by doctors and nurses. We would suspect that 18 cases (5.1%) were related to the occupations, of which 13 cases (3.7%) were in occupational injuries and 5 cases (1.4%) were in occupational diseases. It should be emphasized in medical education that the occupational and environmental histories were thoroughly investigated to make a correct diagnosis and appropriate treatment and that the standard forms for occupational history taking should be developed.

인공타액에서 염소이온과 황이온 농도가 치과용 귀금속계 합금의 변색 및 부식저항에 주는 영향 : 1. 시판 치과용 귀금속계 합금 1. DENTAL COMMERCIAL NOBLE METAL BASED ALLOYS

임범순,문현정,김철위 대한치과기재학회 1998 대한치과재료학회지 Vol.25 No.2

The object of this study was to study effect of Cl- and S²- ions on tarnish and corrosion resistance of dental noble metal alloys in the artificial saliva. Twenty-four commercial dental noble metal based alloys(five for high-Au based alloys, seven for low-Au based alloys, four for Pd-based alloys, and eight for Ag-Pd based alloys) were investigated by the Potentiostat and the Spectrophotometer. Modified Fusayama's artificial salivas with various concentrations of Cl- ion(1.22, 12.22, 24.44, and 61.10 mM/ℓ) and S²- ions(0.01, 0.10, 0.20, 0.35, 0.50, 1.00, 5.00, 10.0, and 20.0 mM/ℓ) were used as electrolytes for test. From the experiments, the following results were obtained. Concentration of Cl- ion in artificial saliva did not in fluence the potentiodynamic polarization curves for dental noble metal alloys. On the other hand, concentration of S²- ion in artificial saliva strongly influenced the potentiodynamic polarization curves for dental noble metal alloys ; corrosion potentials were decreased up to 500 mV and current densities were increased by 100 times. In color change measurements after potentiodynamic polarization curve test, the values of ΔE for high-Ae and Pd-based alloys were increased as the concentration of S²- increased up to 1.00 mM and then were reached a plateau at higher concentration of S²-. For low-Au and Ag-Pd based alloys, the values of ΔE were drastically decreased as the concentration of S²- increased up to 1.00 mM and then were reached a plateau at higher concentration of S²-. By determining the color of an alloy before and after exposure to a test solution, the color changes were ranged of 4∼6 for high-Au and Pd-based alloys and 20∼35 for low-Au and Ag-Pd based alloys.

유기용매에서 치과용 콤포짓트 레진의 시효처리에 따른 표면조도 및 색 변화

임범순,김철위,문현정 대한치과기재학회 1999 대한치과재료학회지 Vol.26 No.1

The purpose of this study was to evaluate the degree of color stability and examine the surface change of esthetic restorative materials in various organic solutions. Ten esthetic restorative materials were used : three chemical-cured composite resins(HPC, PAS, and PAL), four light-cured composite resins(CHA, Z100, AEL, and FLO), three light-cured polyacid modified composite resins(HYT, DYR, and COM). Specimens were prepared as disks of 14mm in diameter and 1.2mm in thickness. After polymerization, specimens were immersed in six different solutions(distilled water, artificial saliva with mucin, 0.1 mole acetic acid solution, 10% hydrogen peroxide solution, and 50% and 75% ethanol) for 1,7,14,21,28,56,84,112, and 140 days. The specimens were maintained at 37℃ throughout the study. Color was measured by CIE L*a*b* against to CIE standard illuminant C reflected on spectrophotometer(CM-3500d, Minolta, Japan.) with specular component exclusive(SCE). After various treatments, the surface of specimens was examined by Surface Roughness Tester(Surtronic 3P, Rank Taylor Hobson Ltd., England.). From the experiment, the following results were obtained. In distilled water, specimens showed an acceptable color stability except for CFS. The water hardening glass ionomer cement, CFS, showed the highest color change(△E>5.0). Color stability of specimens in artificial saliva with mucin was similar to that in distilled water. CFS and KTM showed high color change(△E>5.0) and it would not be acceptable in the clinical situation. In acetic acid solution, all of the glass ionomer cements and compomer specimens showed high color change due to the dissociation of metal-polyacrylate by chemical reaction with H+ ions. CFS, FLC, and FLT showed high color change in ethanol. Color change of specimens in 50% ethanol was higher than that in 75% ethanol. 10% hydrogen peroxide solution resulted in high color change for chemical-cure glass ionomer cements and destroyed the specimens. FLC and CPG showed high color change due to oxidation of residual reaction accelerator and inhibitor by hydrogen peroxide.

콤포짓트 레진의 중합체계에 따른 중합률 및 잔류단량체 유출

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

Newly developed curing units for the dental composite resins are claimed to result in optimum properties and short curing time. The purpose of this study was to detemine the curing effectiveness of the curing units, and to evaluate the relationship between the degree of polymerization and leachability of residual monomer. Three composite resins were tested (Z100; z100, Herculite XRV; HX, Heliomolar; HM). Disk specimens of 2 mm in thickness and 6 mm in diameter were cured with a plasma arc [Apollo 95E; at 1370 mW/㎠, for 5 sec.(A5), 10 sec.(A10), 15sec(A15)], halogen lamp [VIP; at 500 mW/㎠, for 13 sec.(V13), 26 sec.(V26), 40 sec.(V40)] and custom made light emitting diode [LED; at 500 mW/㎠, for 13 sec.(L13), 26 sec.(L26), 40 sec.(L40)]. Specimens were immersed in 75% ethanol for 7 days. Eluates of the composites were analyzed by a high-performance liquid chromatography, and the degree of polymerization of composites were determined by a Fourier transform infrared spectroscopy. To obtain the sufficient curing by a plasma arc, the curing time should be longer than 10 sec. When the same light energy was irradiated, LED showed similar curing performance to halogen lamp. The light energy and the degree of polymerization was not correlated (p>0.05), but the light energy and the leachability of residual monomer was correlated (p<0.05). The leachability of residual monomer (TEGDMA+BisGMA) depended on the degree of polymerization.

저칼슘식이로 사육한 생쥐의 골수세포 배양에 의한 파골세포양세포의 형성

박주철,강선주,임도선,김현만,고재승 대한구강해부학회 1995 대한구강해부학회지 Vol.19 No.1

Although it is now well established that osteoclasts are derived from mononuclear hematopoietic stem cells, most likely within the granulocyte-macrophage lineage, the exact differentiation process of osteoclast precusors has only been partially discovered. This study was carried out to investigate the following topics by examining the osteoclast-like cell formation from the calcium-deficient mouse bone marrow cells; 1) the effect of calcium deficiency on the formation of the mononuclear phagocytes and the mononuclear precusors of the osteoclast in the mouse bone marrow; 2) the effect of TNF (tumor necrosis factor)-α on the differentiation of osteoclast-like cells from the calcium-deficient mouse bone marrow culture; 3) the formation of the osteoclast-like cell from the calcium-deficient mouse bone marrow mononuclear cells and the relationship between the osteoblast cell line(MC3T3E1) and osteoclast-like cell formation; 4) formation of the osteoclast-like cells from the mononuclear cells which were col1ected from PTH-pretreated mouse bone marrow cells to investigate the relationship between PTH and calcium deficiency in osteoclast-like cell formation. Bone marrow cells were isolated from marrow of mouse feeding normal diet or calcium deficient diet for 7 and 14 days. Bone marrow mononuclear cells were fractionated by cetrifugation on Hypaque-Ficoli density gradients. PTH-pretreated mouse bone marrow mononuclear cells were obtained by collecting the nonadherent cells after the culture of normal mouse marrow cells with PTH for 6 days. The prepared cells were cultured on dentin disc at the concentration of 1.5-2 X 10^(6) cells per 0.5ml of a-MEM containing 10% FCS for 3, 5 and 7 days. Thereafter, TRAP staining, NSE staining, effect of calcitonin on the osteoclast-like cell and scanning electron microscope analysis of resorption lacunae on the dentin disc were performed. The results were as follows; 1. Number of the osteoclast precusors and mononuclear phagocytes in bone marrow was increased by calcium-deficient diet. 2. More osteoclast-like cells were formed from the calcium-deficient mouse bone marrow cells than from normal cells. 3. Formation of osteoclast-like cells was significantly stimulated by TNF-α in normal mouse bone marrow cells and calcium-deficient mouse bone marrow cells at concentration of l0ng/ml and 100ng/ml. 4. Osteoblast cell line(MC3T3E1) did not play an important role in osteoclast-like cell formation. 5. Formation of the osteoclast-like cells from the mononuclear cells which were collected from PTH-pretreated mouse bone marrow cells was similar to that of calcium-deficient mouse bone marrow mononuclear cells, which suggests that the effect of calcium deficiency in osteoclast formation may be mediated by PTH.

온도변화가 교정용 니켈-티타늄 호선의 상-변태에 주는 영향

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

The purpose of this study was to evaluate the change of phase transformation and mechanical properties of orthodontic Ni-Ti wire by temperatures changes (0 ℃, 20 ℃, 37 ℃ and 60 ℃) using three-point bending tests and to investigate the phase transformation behavior by microstructure analysis and X-ray diffraction in greater detail. The transition temperature range (TTR) of orthodontic Ni-Ti wires was analysed by DSC for the reference of proportion of martensite to austenite matrix. From this study the following results were obtained. In SM group, as the temperature decreased to 20 ℃ and 0 ℃, superelasticity loop showing at 37 ℃ in load-deflection curve disappeared and the critical load of stress induced martensite transformation decreased (p<0.01). In SE group, the load increased as the temperature increased as the temperature increased under certain temperature (p<0.01). From the microscope, the proportion of stripe-shaped martensite plate to austenite matrix was higher in NEO, active martensite alloy, than OPTI, the active austenite alloy. The (002) peak indicating martensite phase clearly appeared when the temperature decreased to -20 ℃ in NEO from the X-ray diffraction spectra. This study indicated that mechanical properties of orthodontic Ni-Ti wires were substantially affected by temperature and we could expect the biological response in periodontal ligament by load fluctuation of wires tied in bracket induced by temperature variation.

치과용 소와열구 전색제의 조성 용출에 관한 실험적 연구

문현정,임범순,김철위 대한치과기재학회 1999 대한치과재료학회지 Vol.26 No.3

From the recent study, it has raised controversy and concern about an estrogenic chemical, bisphenol-A, which was released from resin-based dental pit and fissure sealants. The purpose of this study was to identify and quantify bisphenol-A and other key leachable components that might be released from dental pit and fissure sealants. Five commercially available light-cured resin-based pit and fissure sealants were studied (CON, PEI, ELI, FSF, and TFI). Specimens were prepared from approximately 50㎕ of each pit and fissure sealants. After curing, specimens were weighed and immersed in two different solution (deionized water and 99.99% ethyl alcohol) for 5 hrs. solutions were analyzed by using High-Performance Liquid Chromatography (HPLC), Gas Chromatography (GC), Mass Spectroscopy (MS), and Ultraviolet Spectrophotometer (US) to detect various leachable components (bisphenol-A ; BPA, triethyleneglycol dimethacrylate ; TEGDMA, bis-glycidyl dimethacrylate ; Bis-GMA). There specimens of each sealant were tested. From the experiment, the following results were obtained : In deionized water, peak with retention time of 2.70 min was identified as TEGDMA and the amount of TEGDMA elution from specimens showed statistically significant difference (p<0.05). In ethyl alcohol, peaks with retention times of 2.70 and 6.04 (4.80) min were identified as TEGDMA and Bis-GMA (UDMA), respectively. TEGDMA eluted from CON, PIF, and ELI showed no statistically significant difference (p>0.05). Also, Bis-GMA eluted from CON, ELI, and FSF showed no statistically significant difference(p>0.05). However bisphenol-A was detected at PIT specimen in ethyl alcohol (retention time : 2.51 min in HPLC and 8.02 min in GC-Mass.). The monomers of pit and fissure sealants were leached within a range of 0.04∼1.94 % of the original weight of the cured sealant for five hours.

인공 석회화 기질의 개발 및 파골세포에 의한 기질흡수에 관한 연구

김현만,박주철,임도선,박수진,김윤지,고재승 대한구강해부학회 1997 대한구강해부학회지 Vol.21 No.1

To develop artificial matrix resorbable by osteoclasts can be used as a model system that biological function of osteoclasts would be assayed in vitro in a standardized condition instead of using heterogenous bone or dentin slices. The present study developed artificial substrates consisted of apatite crystals. collagen gen. agar, apatite crystals under collagen film, mixture of apatite crystals and collagen, and mixture of agar and apatite crystals. And osteoclastic attachement and resorption activity on the each substrate was assayed in vitro. Osteoclasts attached to apatite crystals, collagen, mixture of apatite crystals and collagen, and mixture of apatite crystals and agar, however, not to agar. This suggested that apatite crystals and collagen should be exposed on the surface of artificial substrate where osteoclasts can attach. Osteoclasts attached to the substrate resorbed the substrate consisted of apatite crystals, mixture of apatite crysals and collagen, and apatite crystals under thin film of collagen, however, not of collagen, mixture of apatite crystals and agar. This suggested that the first phase of osteoclasts in resorbing matrix is to secrete acid and the end result of this phase, whatever it may be, may activate secretion of hydrolytic enzymes specific to organic components.

구리 지역에서 조사한 고혈압의 인지도, 치료률 및 관리률

홍철호,김순길,홍택원,이제,신진호,이재웅,김경수,김정현,임헌길,이방헌 대한간질학회 2003 대한간질학회지 Vol.9 No.1