• Restorative Dentistry and Endodontics
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• 제30권5호
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• pp.402-408
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• 2005

난소 절제술을 시행한 백서에서 에스트로겐 호르몬의 결핍으로 인한 상아-치수 복합체의 변화를 관찰하였다. 30 마리의 암놈 Sprague-Dawley rats을 두 군으로 나누어 1 군은 Sham-surgery를 시행하였고, 2 군은 양측 난소 절제술을 시행하였다. 백서는 12주 뒤에 모두 희생시켜, 하악 치아와 인접한 치주조직을 포함하여 절제하였고, $10\%$ 중성 포르말린 용액에 고정하였다. 두 군의 차이점을 비교하기 위하여 방사선 사진을 촬영하고, osteonectin을 이용한 면역 화학 염색법을 시행하였다. 조직 형태학적 차이점을 측정하기 위하여 영상 분석 프로그램을 사용하였고, 분석 방법으로는 Paired t-test를 사용하였다 (p < 0.05). Osteonectin을 이용한 면역 화학 염색 결과, 두 군간에는 유의성 있는 차이점이 존재하였다. 난소 절제술을 시행한 백서군에서는 전상아질층의 두께가 현저히 증가하였고, Sham-surgery 군에서는 전상아질 층과 치수 조직에서 osteonectin이 좀 더 특이적으로 염색되어 나타났다. 이러한 결과로 결론지어보면, 백서에서 인위적으로 난소 절제술을 시행하였을 때 광화되지 않은 전상아질층의 두께가 증가하고, 치수 조직과 전상아질층내의 osteonectin 함량이 감소되며, 결국 에스트로겐 결핍은 조상아 세포의 기전을 변화시킨다고 할 수 있다.

• 대한소아치과학회지
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• 제7권1호
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• pp.75-83
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• 1980

Rickets is not the deposite of minerals in the skeletal tissue and the retardation of skeletal growth in growing in growing animals. This study was undertaken to investigate the histologic effects of experimental rickets on the dental structure of the albino rats, and to show the relationship between the histological effects and the pulpal disease which induced premature loss of the primary teeth. This study was based on material obtained from 40 white rats that were placed on a rachitogenic diet for a period 1 to 56 days after weaning (at 24 days). In addition, a study was made of 25 litter mates, 24 to 80 days, that were fed a normal diet. The following results were obtained: 1. Enamel formation and calcification showed no significant changes and no hypoplasia. 2. Dentin formation and calcification was retarded and disturbed. In the experimental group, predentin/calcified dentin was remarkablly increased. 3. Newly formed dentin showed interglobular texture (less homogenous calcification) and the predentin was significantly wider and thicker, and there was an irregular wave in the basal portion of the rat's incisors. 4. In cementum, Matrix formed at almost a normal rate but calcification was defective. So cementoid tissue was increasesd. 5. The formation of the alveolar bone was at almost a normal rate but calcification was retarded. The trabecular bone was filled with osteoid tissue and thicker than in normal groups.

• Restorative Dentistry and Endodontics
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• 제13권2호
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• pp.307-322
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• 1988

The purpose of this study is to evaluate the pulpal responses to the base materials such as zinc oxide eugenol cement, calcium hydroxide, zinc phosphate cement, polycarboxylate cement and glass ionomer cement. The 100 caries free dog teeth were devided into 2 groups by remaining dentin thickness (Group A: 0.4-0.6 mm, Group B: 0.8-1.0 mm) and each group were devided into 5 subgroups. The intervals of observation period are 3days, 1 week, 2 weeks, 4 weeks and 8 weeks respectively after experiment. The specimens were fixed with 10% formalin and decalcifed in 5% nitric acid. All specimens were stained with Hematoxylin-Eosin and examined histopathologically. The results were as follows. 1. In group A, atropy or hyperplasia in odontoblasts were seen in zinc oxide eugenol cement, calcium hydroxide and zinc phosphate cement. No changes in odontoblasts were seen in polycarboxylate cement and glass ionomer cement. 2. In group A, increase of predentin were seen in all experimental materials. 3. In group A, vascular congestion were seen in all experimental materials and inflammation were seen on 3 days in zinc oxide eugenol cement, 8 weeks in zinc phosphate cement and hemorrage were seen on 3 days in zinc phosphate cement. 4. In group B, changes of odontoblasts were not seen all experimental materials. 5. In group B, increase of predentin and vascular congestion were seen in all experimental materials but inflammation were not seen.

• Restorative Dentistry and Endodontics
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• 제12권2호
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• pp.73-80
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• 1987

The present study was designed to help elucidate the effect of glass ionomer cements on the exposed dental pulp by means of histologic examination. A total of 40 cavities of class V were prepared on the teeth of 4 dogs with exposure of 1mm in diameter on the bases of them. 20 cavities were filled with glass ionomer cement as the experimental group and the other 20 cavities were filled with zinc oxide eugenol cement as the control group. The dogs were sacrificed at one, two, three, and four weeks after filling, and the specimens were routinely prepared and stained with Hematoxylin-Eosin. The obtained microscopic findings were as follows: Inflammatory cell infiltrations were observed in control in 1 week, which decreased markedly with time. In all control groups, hemorrhage around exposed pulp tissue and coagulation change of pulp were observed. Secondary dentin formation and thickened predentin were observed in 4 week cases, and the recovery of pulp tissue was favorable on the whole. Inflammatory cell infiltration was observed in all GIC groups. Proliferation of blood vessel and congestion were observed with coagulation changes around the exposed pulp tissue. Secondary dentin formation and thickened predentin were observed in 3 weeks. In the experimental 4 week case, secondary dentin formation was evident. On the whole, pulpal irritation of glass ionomer cement was relatively severe. Recovery of pulp tissue in GIC groups was less favorable compared with that of ZOE groups.

• 대한치과의사협회지
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• 제11권3호
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• pp.217-219
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• 1973

The observation of calcium salts in dentinogenesis was performed with Von Kossa-toluidine blue method and metachromasia were observed on the portion of border that is beginning the calcification in dentin and predentin, which is positive Von Kossa reaction.

• Restorative Dentistry and Endodontics
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• 제21권1호
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• pp.35-53
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• 1996

The development and repair requires the formation of new tissues comprised of various extracellular matrix components. The present study investigated the formation and distribution of the major ECM components such as type I collagen, type III collagen, fibronection, bone sialoprotein, and osteonection during development and repair. For developing observation. Sprague-Dawley rats weighing $27{\pm}1gm$ were sacrificed. For repair observation, Sprague-Dawley rats weighing $110{\pm}5gm$ were used. The pulp perforation were prepared on mesial surface of the maxillary first molar by using 1/2round bur. At 5 days after perforation, rats were sacrificed by perfusion with 3 % paroformaldehyde. The maxillary first molar region were cut, demineralized, dehydrated and embedded in paraffin. Immunostaining the ECM components was achieved by the avidin-biotin complex method. The results as follows : 1. Bright immunoreaction for fibronectin was present in the basement membrane at the inner epithelial-mesenchymal interface, especially concentrated in the blood vessel walls, cell membrane of odontoblasts, and initial predentin. 2. Type I and III collagen was observed in the newly formed pulp tissue, predentin, and its intensity increased as more of these components during repair. 3. Strong immunostaining for bone sialoprotein and osteonectin was found in dentin while no or weaker staining was observed loose connective tissue of the pulp. 4. These results suggest that develpment and repair is achieved through a series of cell differentiation and attachment by the specific ECM components.

• International Journal of Oral Biology
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• 제40권1호
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• pp.1-9
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• 2015

Osteocalcin (OC) is the most abundant noncollagenous protein of extracellular matrix in the bone. In an OC deficient mouse, bone formation rates are increased in cancellous and cortical bones. OC is known as a negative regulator of mineral apposition. OC is also expressed in the tooth of the rat, bovine, and human. However, little is known about OC during tooth development in Xenopus. The purpose of this study is to compare the expression of OC with mineralization in the developing tooth of Xenopus, by using von Kossa staining and in situ hybridization. At stage 56, the developmental stage of tooth germ corresponds to the cap stage, and an acellular zone was apparent between the dental papilla and the enamel organ. From stage 57, calcium deposition was revealed by von Kossa staining prior to OC expression, and the differentiated odontoblasts forming predentin were located at adjoining predentin. At stage 58, OC transcripts were detected in the differentiated odontoblasts. At stage 66, OC mRNA was expressed in the odontoblasts, which was aligned in a single layer at the periphery of the pulp. These findings suggest that OC may play a role in mineralization and odontogenesis of tooth development in Xenopus.

• 대한소아치과학회지
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• 제11권1호
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• pp.131-143
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• 1984

150 rats weighting about 150gm were devided into control group of 80 and experimental group of 70. Control group was subdivided into the irradiated vitamin D injection group and X-ray irradiated group. Experimental group was given 2.0mg ergocalciferol by four intramuscular injection prior to X-ray irradiation with single 800 rads and 1,500 rads respectively. Experimental animals from each group was sacrificed after 1, 3, 7, 14, and 28 days and their incisors were investigated by histopathological examination. The results were as follows; 1. In the irradiated groups, it showed dentin hypoplasia and formation of dentinoid substance caused by degeneration of odontoblast at the early stage. Especially, 1,500 rads group which was severely effected showed formation of osteoid dentin at the apical portion and severe injuries of dental papilla at the first week. 2. In the vitamin D2 administration group, it showed thinned dentin layer at the early stage but, taking time, predentin and dentin layer was thickened. At the fourth week, dentin was chiefly composed of interglobular dentin, especially in the lingual portion. 3. Using in combination of overdose vitamin D2 administration and X-ray irradiation, it effected severely odontoblast, undifferentiated mesenchymal cells around tooth germ and pulp tissue. At the early stage, dentin layer was thinned but, taking time, it was thickened and composed of interglobular dentin caused by calcification of predentin layer. 4. In 800 rads irradiation after the overdose vitamin D2 administration, it showed formation of osteoid dentin in the lingual portion at the first week. In the 1,500 rads irradiation after the overdose vitamin D2 administration, it showed formation of osteoid dentin and degeneration of ameloblast in both buccal and lingual portion at the first week, and enamel hypoplasia caused by edema and loss of polarity of ameloblasts at the second week. 5. By the entire experiment, the overdose vitamin D2 administration and X-ray irradiation effected severely odontoblasts, undifferentiated mesenchymal cells of dental papilla, and primitive cells of tooth germ among the dental tissue. Especially using combination of overdose vitamin D2 administration and X-ray irradiation also effected ameloblasts, resulting in enamel hypoplasia.

• 대한치과교정학회지
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• 제35권2호
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• pp.106-115
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• 2005

이 연구는 흡수중인 유치를 대상으로 인도메타신이 치근흡수에 미치는 영향을 조사하고. 치근흡수에 관련된 주위 조직의 변화를 관찰하기 위하여 시행되었다. 인도메타신은 파골세포의 수를 감소시키고 골흡수를 감소시키며, 골형성도 감소시키는 것으로 보고되어 왔으나 형태와 기능이 유사하다는 파치세포에 미치는 영향에 관한 연구는 희소하다. 생후 12-13주된 잡견 6마리를 통상적 복용량인 인도메타신 2 mg/kg/day를 14일간 투여한 군과 과량의 8mg/kg/day를 14외간 투여한 군과 대조군으로 구분하였으며 흡수중인 하악 절치를 연구대상으로 하였다 연구대상 치아는 $5{\mu}m$ 두께의 절편을 만들고, H&E 중염색, Masson의 trichrome 염색을 시행하고 광학현미경으로 검경하였으며, 파치세포의 수와 핵의 수를 비교하였다. 관찰 결과 유치 치근 흡수 조직은 골개조 소견과 함께 염증소견과 유사한 소견을 보였다. 흡수중인 유치의 치수는 치근흡수부위에 가까운 조상아세포층은 변성의 소견을 보이나 멀리 떨어진 치수는 종상인 소견을 보였으며 인도메타신이 투여된 실험군에서는 파치세포의 수적 감소와 핵의 수적 감소를 미약하게 나타냈다 그러나 인도메타신이 흡수중인 치아의 치수에 미치는 영향은 관찰되지 않았다. 이상의 결과에 의하면 인도메타신은 파치세포의 수적 감소를 미약하게 일으키며 장기간의 인도메타신 투여는 유치 치근흡수의 지연을 초래할 가능성이 있음을 시사한다.

• Restorative Dentistry and Endodontics
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• 제9권1호
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• pp.107-114
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• 1983

The purpose of this study was to observe the effect of cleansing action of irrigation solutions which was 3% $H_2O_2$ and 5% NaOCl, and 15% EDTA solution on the root canal wall. After treatment with the irrigant, each sample was dehydrated, and coated with 200~250${\circ}$A of gold, and observations were made with the use of scanning electron microscope. The results were as follows: 1. In the root canal walls irrigated with 3% $H_2O_2$ and 5% NaOCl solution without instrumentation after extirpation through barbed broach, the predentin of root canal wall was found scarely affected, and the wall was shown retaining network structure and fibrous organic matters. 2. When 15% EDTA was applied as irrigants for 60, 90 and 120 seconds after instrumentation, there was no signigicant difference of the cleansing effect of the elapsed times which were 90 and 120 seconds on the root canal wall, but in the applied time which was 120 seconds, the canal wall was the cleanest. Therefore it was thought that the most suitable application time of 15% EDTA as the irigants was 120 seconds.