• 대한치과의사협회지
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• 제12권5호
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• pp.327-332
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• 1974

The effects of enamel solubility by the varying concentration of fluoride and phosphate as well as pH of the acid fluoride-phosphate solutions were tested and compared with th 7% stannous fluoride solution. The smooth surface of the sound permanent 1st premolars were demineralized by the Buttner's method. And the phosphorus extracted from the 1st premolars were analyzed by the Fiske and Subbarow's method. Enamel smooth surfaces treated with the acid fluoride-phosphate solution and the 8% stannous fluoride solution were obserbed electron-microscopically by the Filmy Replica method. The results of this study were summarized as follows: !. The least enamel dissolution rate was observed at the acid fluoride-phosphate solution contained 1.25% fluorine, 0.5% phosphate, and pH 4. 2. The anti-cariogenic effects comparison between the acid fluoride-phosphate solution and 8% stannous fluoride, the former was higher.

• 대한치과보존학회:학술대회논문집
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• 대한치과보존학회 2001년도 추계학술대회(제116회) 및 13회 Workshop 제3회 한ㆍ일 치과보존학회 공동학술대회 초록집
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• pp.567.2-567
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• 2001

The purpose of this study was to evaluate the shape, the composition of Calcium Hydroxide Points (CH Point) and to determine the pH level in water. The shape of CH Point was measured by using a profile projector. The composition of the CH Point was analyzed by the X-ray diffraction and the EPMA. ＃60 CH Point was stored in 10ml of demineralized water that was replaced every day or not replaced for 7 days period. The pH levels of the water were measured by using an ion electrode with an ion meter every day.(omitted)

• 대한소아치과학회지
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• 제23권4호
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• pp.931-936
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• 1996

Many kinds of soluble calcium salts such as calcium lactate are known to reduce the enamel demineralization. In this study, calcium lactate was tested for its effect on the demineralization process of hydroxyapatite. Synthetic hydroxyapatites were used as a standardized material instead of human enamel which is rarely heterogenous. And, for the purpose of hydroxyapatite demineralization, lactic acid was used. By comparing the weight of hydroxyapatite pre-demineralization and post-demineralization, it was possible to examine the effect of calcium lactate on demineralization. The weight of demineralized hydroxyapatite was reduced by about 46% and 59% with 20mM and 40mM calcium lactate, respectively. In conclusion, low concentrations of calcium lactate showed an inhibitory effect on the demineralization of synthetic hydroxyapatite.

• Applied Microscopy
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• 제28권4호
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• pp.551-561
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• 1998

The autometallographic method was used to demonstrate the localization of mercury deposits in spleen of mouse. The mercury deposits were identified with the light and electron mocroscope. Mice were treated with methylmercuric chloride in the drinking water (demineralized water) for 40 days. Control and mercury treated groups showed no significant differences in mean body weight and spleen weight per one mouse. Mercury grains were appeared in the germinal center of white pulp consist of a preponderancing lymphocytes, not in red pulp and capsule. At the ultrastructural level, mercury deposits were restricted to lysosomes of macrophage and lymphocyte. Specially, volume in lysosomes of the macrophage was increased. These results suggest that mercury localization in lysosomes is associated with the change of immune activity.

• 대한소아치과학회지
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• 제43권1호
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• pp.44-50
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• 2016

본 연구는 탈회 유전치에 3가지 불소바니쉬를 이용하여 인공우식의 재광화 효과를 비교 평가하였다. 인공우식용액에 40개의 건전한 유전치 시편을 침적시킨 후, $37^{\circ}C$ 항온기에 7일 동안 보관하여 유전치에 탈회를 형성하였다. Cavity shield$^{TM}$, V varnish$^{TM}$, MI varnish$^{TM}$를 1주일에 한 번씩 3주 동안 탈회된 유전치에 도포 후 불소바니쉬 종류에 따른 미세경도 변화를 평가하였다. 1주차에서는 MI varnish$^{TM}$군이 가장 높은 재광화 효과를 보였고 다음으로 V varnish$^{TM}$군이 높았으며, Cavity shield$^{TM}$군이 낮은 재광화 효과를 보였으며, 세 군 모두 유의한 차이는 없었다(p > 0.05). 2주차에서는 V varnish$^{TM}$군이 가장 높은 재광화 효과를 보였으며 그 다음으로 MI varnish$^{TM}$군 높았지만 V varnish$^{TM}$군과 유의한 차이는 없었다(p > 0.05). Cavity shield$^{TM}$군은 V varnish$^{TM}$군과 MI varnish$^{TM}$군에 비해 유의하게 낮은 재광화 효과를 보였다(p < 0.05). 3주차에서는 V varnish$^{TM}$군이 나머지 두 군과 유의한 차이를 보이며 가장 높은 재광화 효과를 보였고(p < 0.05), 다음으로 MI varnish$^{TM}$군이 높았으며 Cavity shield$^{TM}$군이 가장 낮은 재광화 효과를 보였지만, MI varnish$^{TM}$군과의 유의한 차이는 없었다(p > 0.05). 총 미세경도 증가량은 Cavity shield$^{TM}$군에 비해 V varnish$^{TM}$군과 MI varnish$^{TM}$군이 높았으며(p < 0.05), V varnish$^{TM}$군과 MI varnish$^{TM}$군 사이 통계학적 유의한 차이는 없었다(p > 0.05).

• 폴리머
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• 제36권6호
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• pp.768-775
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• 2012

해조류로부터 얻어지는 알지네이트는 캡슐화된 세포의 생존율에 긍정적인 영향을 끼치며 살아있는 세포를 신속하게 포접하여 캡슐화할 수 있어 세포이식을 위한 생체재료 분야에 널리 쓰인다. 탈미네랄화된 골분(DBP)은 천연 뼈조직으로부터 유래되어 조직과의 반응정도가 낮고 항원성 또한 낮아 임상에 적용되어 사용되어 왔다. 알지네이트에 비율별 DBP을 포함시켜 연골세포를 파종한 뒤 미세캡슐을 제조한 후 MTT 분석을 통하여 세포의 부착 및 증식률을 관찰하였고 glycosaminoglycan(sGAG)와 콜라겐 함량 측정과 연골세포의 특정유전자 표현형을 확인하기 위하여 PCR을 실시하였다. 또한 연골세포가 파종된 알지네이트 미세캡슐을 누드마우스의 피하에 이식한 뒤 적출하여 면역화학적 염색을 실시하였다. 실험 결과 1%의 DBP를 함유한 알지네이트 미세캡슐에서 가장 높은 세포 증식률을 보였고 표현형 유지에도 긍정적인 영향을 미치는 것을 확인하였다. 이번 연구 결과를 토대로 알지네이트와 DBP를 이용한 미세캡슐을 제조함으로써 DBP내의 성장인자와 알지네이트의 상호작용으로 인하여 연골세포의 성장에 긍정적인 영향을 미쳐 생체공학적 지지체로 적합할 것으로 예상된다.

• Restorative Dentistry and Endodontics
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• 제23권1호
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• pp.141-161
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• 1998

The depth and patterns of demineralization according to the difference in concentration and application time of phosphoric acid were observed through the transmission electron microscope, and shear bond strengths to the acid -conditioned dentin were then measured and compared with the TEM results. To investigate the influence of polymer addition into the phosphoric acid and the effect of difference in concentration and application time of the acid, the specimens were randomly divided into 9 groups. Among the specimens, the exposed dentin surfaces were acid-conditioned with 10% polymer-thickened phosphoric acid(All Bond 2, Bisco, U.S.A.) and aqueous 10%, 20%, 30%, 40% phosphoric acid for 20 seconds, The rest of the specimens were acid-conditioned with 10% phosphoric acid for 15s, 30s, 60s, 120s respectively. The specimens were immersed in 4% glutaraldehyde in 0.1M sodium cacodylate buffer and postfixed with 1 % osmium tetroxide without decalcification and then observed under a JEOL Transmission Electron Microscope(JEM 1200 EX II, Japan). After the specimens were acid-conditioned as the above, primer and adhesive resin were applied to blot-dried dentin and shear bond strengths were then measured and analysed. The results were as follows : 1. The intertubular demineralization depth of 4.0-$5.0{\mu}m$ in 10% polymer-thickened phosphoric acid gels was similar or slightly deeper than that of 4.0-$4.5{\mu}m$ in aqueous 10% phosphoric acid solution. 2. The intertubular demineralization depth of aqueous 20%, 30% and 40% phosphoric acid solution was 6.5-$7.0{\mu}m$, 6.5-$7.5{\mu}m$ and 9.0-$15.0{\mu}m$ respectively. It showed that the depth of dentin demineralization is partly related to the concentration of phosphoric acid solution. 3. The intertubular demineralization depth of aqueous 10% phosphoric acid solution in application time for 15s, 30s, 60s and 120s was 2.5-$3.0{\mu}m$, 4.0-$6.0{\mu}m$, 6.5-$7.0{\mu}m$ and 8.5-$14.0{\mu}m$ respectively. It showed that the depth of dentin demineralization is directly related to the application time of phosphoric acid solution. 4. The partially demineralized dentin layer between demineralized collagen layer and unaffected dentin was showed to a width of 0.5-$1.0{\mu}m$ in lower concentration groups treated with aqueous 10% phosphoric acid for 20s, 60s, 120s and 20% phosphoric acid for 20s. 5. The demineralization effect at the border of intertubular-peritubular junction was less evident than that in the peritubular and intertubular dentin. The collagen fibers in the intertubular dentin had a random orientation, whereas those that lined the tubules were circumferentially aligned. The cross-linkage of dentinal collagen in demineralized collagen layer was clearly seen. 6. A statistically significant difference of bond strengths according to the difference in phosphoric acid concentration did not exist among the groups treated with 10%, 20%, 30% and 40% acid solution (P>0.05). However, bond strengths to the treated dentin with 10% phosphoric acid solution for 30s were significantly higher than that for 120s (P<0.05).

• Applied Microscopy
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• 제16권2호
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• pp.1-13
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• 1986

The purpose of this study was to investigate the morphology and intercellular junctions of the odontoblast of dental pulp in the rat incisor by means of the freeze fracture electron microscopy. Twenty male Sprague-Dawley rats weighing $150{\sim}200g$ were used. After being anesthetized by an intraperitoneal injection of 0.5 ml sodium pentobarbital per kg in body weight(60 mg/ml) the animals were perfused with 2.5% glutaraldehyde-2% paraformaldehyde fixative in 0.1 M cacodylate buffer, pH 7.2 through the ascending aorta for one hour. The incisors were carefully extracted from the jaws and demineralized by suspending them in 0.1 M EDTA in 3% glutaraldehyde (pH 7.2) for two weeks. After demineralization, the specimens were obtained from the portion divided into five equal parts. For freeze-fracture replication, demineralized tissues were infiltrated for several hours with 10%, 25% glycerol in 0.1M cacodylate buffer as a cryoprotectant and then frozen in liquid Freon 22 and stored in liquid nitrogen. Fracturing and replication were done in Balzers BAF 400D high-vacuum freeze-fracture apparatus at $-120^{\circ}C$ under routine $5X10^{-7}$ Torr vacuum. The tissue was immediately replicated with platinum unidirectionally at $45^{\circ}$ angle and reinforced with carbon at $90^{\circ}$ angle unidirectionally or by using a rotary stage. The replication process was monitored by a quartz-crystal device. The replicas were immersed in 100% methanol overnight. The tissue was then digested from the replica by clorox (laundry bleach), placed into 5% EDTA, and washed repeatedly with distilled water. The replicas were picked up on 0.3% formvar-coated 75 mesh grids and examined in the JEOL 100B electron microscope. The results were as follows; 1. Both in thin sections and freeze-fracture replicas, three types of intercellular junctions were recognizable in the plasma membrane of odontoblast: gap junction, tight junction and desmosome-like junction. 2. The nuclear pores were evenly distributed over the nuclear envelope. The pore complex formed a ring about 70 nm in diameter. 3. Gap junctions were found between odontoblasts as well as odontoblasts and neighbouring pulp cells (fibroblast, subodontoblastic cell process, nerve-like fibre). Gap junctions, which were round, ellipsoid and pear-shaped and 600 nm in diameter, were observed in the odontoblast. 4. Numerous round and ellipsoid gap junctions could be frequently seen on the plasma membranes in cell body and apical part of the odontoblasts. On the P face, the junctions were recognized as a cluster of closely packed particles, measuring about 9 nm in diameter, and on the E face, the junctions were recognized as a shallow grooves.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제31권3호
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• pp.198-206
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• 2009

Purpose: The aims of this study were to assess the in vitro co-culturing pattern of isolated skin-derived precursor cells (SKPs) with a mixed demineralized bone (DMB) and fibrin glue scaffold and to evaluate in vivo osteogenesis after transplantation of autogenous SKPs with a these mixed scaffold in the animal's mandibular defects. Materials and Methods: We isolated SKPs from the ears of adult 4 miniature pigs. The isolated SKPs were co-cultured with a mixed DMB and fibrin glue scaffold in a non-osteogenic medium for 1, 2, and 4 weeks. Histological characteristics of in vitro co-cultured cells and scaffold were evaluated. $1{\times}10^7\;cells/100\;{\mu}l$ of autogenous porcine SKPs were grafted into the mandibular defects with a DMB and fibrin glue scaffold. In the control sites, only a scaffold was grafted, without SKPs. After two animals each were euthanized at 2 and 4 weeks after grafting, the in vivo osteogenesis was evaluated with histolomorphometric and osteocalcin immunohistochemical studies. Results: Homogeneously shaped skin-derived cells were isolated from porcine ear skin after 3 or 4 weeks of primary culture. In vitro osteogenic differentiation of SKPs was observed after co-culturing with a DMB and fibrin glue scaffold in a non-osteogenic medium. Von Kossa-positive bone minerals were also noted in the co-cultured medium at 4 weeks. As the culture time progressed, the number of observable cells increased. Trabecular new bone formation and osteocalcin expression were more pronounced in the SKP-grafted group compared to the control group. Conclusion: These findings suggest that autogenous SKP grafting with a DMB and fibrin glue scaffold can serve as a useful alternative to bone grafting technique.

• 대한소아치과학회지
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• 제43권4호
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• pp.443-451
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• 2016

본 연구는 현재 시판되고 있는 불소 바니쉬 제품의 불소이온 유리 능력을 측정하고 이와 함께 정량 광 형광기를 이용하여 치질의 재광화 효과를 비교, 분석하였다. 평가하고자 하는 불소 바니쉬는 다음과 같은 6가지 제품을 대상으로 하였다; $FluoroDose^{(R)}$ (FD, Centrix Inc., USA), $Enamelast^{TM}$ (EL, Ultradent Product Inc., USA), $Clinpro^{TM}$ white varnish (CW, 3M ESPE, USA), $CavityShield^{TM}$ (CS, 3M ESPE, USA), V $varnish^{TM}$ (VV, Vericom, Korea), MI $varnish^{TM}$ (MI, GC, Japan). MI $varnish^{TM}$와 V $varnish^{TM}$에서 누적 불소이온 유리량과 재광화율이 가장 높게 나타난(p < 0.05) 반면 CS $varnish^{TM}$가 가장 낮은 누적 불소이온 유리량과 재광화율을 보였다(p < 0.05).