• International Journal of Oral Biology
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• 제33권4호
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• pp.187-195
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• 2008

Reparative dentine formation requires newly differentiated odontoblast-like cells. Therefore, identification of the molecule that stimulates the odontogenic differentiation of precursor cells in the tooth pulp will be helpful for the development of strategies to repair damaged pulp. In this study, we examined the effect of N-acetylcysteine (NAC) on the odontogenic differentiation of MDPC-23 cells, a mouse odontoblast-like cell line derived from dental papilla, and primary cultured rat dental papilla cells (RDPCs). NAC (1-30 mM) suppressed production of reactive oxygen species in MDPC-23 cells in a dose-dependent manner. Although 5 to 20 mM NAC did not alter MDPC-23 cell proliferation, 1 or 30 mM NAC significantly inhibited it. NAC enhanced mineralized nodule formation and the expression of several odontoblast differentiation-associated genes in both RDPCs and MDPC-23. This NAC stimulatory effect was significant, even at concentrations lower than 1 mM. However, NAC did not stimulate expression of bone morphogenetic protein-2, -4, or -7, which are known to enhance odontogenic differentiation. Since reactive oxygen species are also involved in the pulp toxicity of resin-based restorative materials, these results suggest that NAC may be a promising candidate for supplementation of dental restorative materials in order to enhance reparative dentine formation.

• 대한치과의사협회지
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• 제9권4호
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• pp.157-160
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• 1971

To compare the effects of various pulp capping agents that are usually applied to human pulp tissue, adult dogs were bred for a certain period and each capping agent was applied experimentally to pulp tissue after vital pulpotomy. Histological observations are as follows. 1) In comparison between methods of vital pulpotomy, one and two appointment method, different courses of healing were observed. In one appointment method, the granulation tissue formation at the amputation sur face of pulp tissue had a tendency to be transformed to scar tissue formation. In two appointment method, more transformation than that of one appointment method from scar tissue to dentin matrix formation were observed. 2) Histologic changes that have appeared in pulp tissue are a) fixation at outer layer b) degeneration at middle layer c) hyperemia and round cell infiltration at inner layer 3) With use of formocresol mixed zinc oxide powder in two appointment method complete formation of dentin matrix were observed. 4) Among the methods and aagents described above formocresol mixed zinc oxide powder in two appointment method appeared to be relatively effective.

• 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.

• Restorative Dentistry and Endodontics
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• 제46권3호
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• pp.40.1-40.12
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• 2021

Objectives: The purpose of this study was to critically evaluate the quality, reliability and educational content of the information of vital pulp treatment videos available on YouTube. Materials and Methods: The keywords "pulpotomy" and "pulp capping" were searched on YouTube on 5th July 2020, until 60 English language videos of each search term with a duration shorter than 15 minutes were acquired. Video characteristics were recorded and Video Power Index (VPI) was calculated. Reliability and educational quality of videos were evaluated using the Modified DISCERN score, the Journal of American Medical Association (JAMA) benchmark criteria and Global Quality Scores (GQS). Videos were categorized by uploading source. Results: Regarding pulpotomy, 31.7% of the videos were uploaded by specialists and 68.3% were directed by non-specialists. In the case of pulp capping, the corresponding percentages were 45% and 55%, respectively. Videos uploaded by specialists had significantly higher modified DISCERN, JAMA and GQS scores compared to those uploaded by non-specialists. Endodontists tended to have the highest reliability and VPI scores. Conclusions: YouTube videos on vital pulp treatment contain low educational quality or incomplete information. Low popularity of dental pulp capping and pulpotomy videos may be attributed to the specialized nature of these procedures. As YouTube represents an important source for patient information about different health topics, reliable informative videos should be uploaded by specialized dental professionals.

• 대한소아치과학회지
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• 제35권1호
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• pp.11-17
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• 2008

본 연구는 Er:YAG laser에 의한 치수의 초기 조직반응과 calcitonin gene-related peptide (CGRP) 함유 신경섬유의 발현을 비교 평가하고자 시행하였다. Er:YAG laser와 conventional bur를 이용하여 상악 제1대구치의 교합면에 와동을 형성하였다. 와동형성 후 48시간 후에 조직을 처리하여 hematoxylin-eosin 염색과 CGRP 면역조직화학을 시행한 후 다음과 같은 결과를 얻었다. 1. Conventional bur를 이용하여 삭제한 경우, 상아질 바닥면은 균열이 없는 평면의 균일한 모양을 보였으며, Er:YAG laser의 경우에는 상아질의 면은 bur에 비해서 파동형의 불규칙적인 형태와 바닥면에서 상아세관의 주행방향을 따라 미세한 균열을 보였다. 2. Er:YAG laser에 의해 손상 받은 치수에서는 혈관확장과 노출된 치수의 손상부위를 따라 bur에서 손상 받은 치수보다 더 많은 염증세포의 침윤과 상아모세포층의 파괴를 보였다. 3. 노출손상 후에 치수신경 말단에서 CGRP 발현은 bur와 laser군 모두에서 손상을 받지 않은 정상 치수에 비해서 증가된 양상을 보였으며, 그 증가된 정도는 laser의 경우에서 더 강하였다. 위의 결과들을 종합하면, Er:YAG laser가 치수손상을 최소화하여 적용되면 치아우식 제거와 와동형성과 같은 여러 수복치료 시 유용하게 사용될 수 있으리라 사료된다.

• Restorative Dentistry and Endodontics
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• 제35권3호
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• pp.152-163
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• 2010

이 연구에서는 mineral trioxide aggregate (MTA)를 in vitro로 인간치수세포에 적용하였을 때 유전자들의 변화를 조사하였다. 실험군은 MTA를 teflon tube (직경 10 mm 길이 2 mm)에 담아 4시간 경화시킨 후HDPCs에 적용하였고, 대조군은 빈tube만을 적용하였다. 6, 24, 72시간 후 total RNA를 추출하여 microarray를 이용하여 분석하여, 2배 이상 또는 절반 이하의 변화를 보이는 유전자 중 선택적으로 역전사 중합효소 연쇄반응(reverse transcriptase polymerase chain reaction)을 사용하여 발현을 확인하였다. 24,546개의 유전자 중에서 109개의 유전자가 2배 이상 up-regulation되었으며(예. FOSB, THBS1, BHLHB2, EDN1,IL11, FN1, COL10A1, TUFT1) 69개의 유전자가 50%이하로 down-regulation되었다(예. SMAD6, DCN). MTA는 bio-inert한 재료라기 보다는 치수세포에 다양한 경로로 영향을 주는 재료로 사료된다. 특히 치수세포의 분화와 증식에 관여하는 유전자의 변화에 영향을 주며 석회화 과정에 관여하는 유전자의 변화에 직접적인 영향을 주리라 사료된다.

• 대한치과의사협회지
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• 제11권3호
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• pp.185-189
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• 1973

Dental amalgam in the clinic practice of dentistry is one of the most important materials. Mercury, one of the component of this alloy, is emitted in the form of vapor after filling as long as 5 days Silver particles penetrate into the dentine deeply along the tubles underneath cavity floor. To determine the permeability of mercury in the teeth following experiments were performed. Class 5 cavities total 40 from 10 dogs were prepared on upper and lower canines and amalgam alloys which contain about 10uCi of radioactive mercury were inserted. The animals were sacrificed 7 days after the experiments and the teeth were decalcified, sectioned and autoradiographed by means of emulsion and stained by H & E. Following are the results obtained from this experiments. 1. Blackened silver grains were found along the dentinal tubules underneath the cavity floor. Beyond the border of dentine and pulp chamber grains were seen in odontoblastic layer (Fig. 1, 2, 3, 4) 2. Underneath the odontoblastic layer, the pulp tissue showed almost normal appearance except slight dilatation of blood vessel.

• Restorative Dentistry and Endodontics
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• 제40권1호
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• pp.75-78
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• 2015

Presented here is a case where 8 canals were located in a mandibular first molar. A patient with continuing pain in mandibular left first molar even after completion of biomechanical preparation was referred by a dentist. Following basic laws of the pulp chamber floor anatomy, 8 canals were located in three steps with 4 canals in each root. In both of the roots, 4 separate canals commenced which joined into two canals and exited as two separate foramina. At 6 mon follow-up visit, the tooth was found to be asymptomatic and revealed normal radiographic periapical area. The case stresses on the fact that understanding the laws of pulp chamber anatomy and complying with them while attempting to locate additional canals can prevent missing canals.

• 대한소아치과학회지
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• 제46권3호
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• pp.337-342
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• 2019

이 연구의 목적은 발치한 매복 과잉치에서 얻은 치수 유래 세포의 줄기세포 특성을 유세포 분석을 통해 알아보는 것이다. 15명의 환자로부터 채취한 정중 과잉치의 치수 세포를 계대 배양하였고, 3계대와 10계대 세포들을 유세포 분석을 이용하여 분석하였다. 간엽성 줄기세포 표지자 관찰에 사용된 항체 표지자(CD)는 양성 표지자로는 CD 73, CD 90, 그리고STRO-1 와 음성 표지자로는 CD 34, CD 45 이었다. 3계대에서 CD 73, CD 90은 각각 94.82%, 98.86%의 양성반응을, CD 34, CD 45는 각각 2.25%, 2.52%로 음성 반응을 보였으며, STRO-1은 20.93%를 나타냈다. 10계대에서는 CD 73, CD 90은 각각 96.62%, 98.61%의 발현을 보였지만, CD 34, CD 45는 각각 3.86%, 4.14%를 나타냈다. STRO-1은 35.62%로 발현되었다. 이상의 결과에서 과잉치 치수 유래 세포는 간엽성 줄기세포의 특성을 가지며, 3계대와 10계대 모두에서 간엽성 줄기세포의 특성을 유지하고 있다고 사료된다. 이에 빠른 성장 속도와 늦은 계대까지 유지되는 줄기세포능을 고려할 때, 치아 유래 줄기세포의 공여부로서 매복 과잉치의 충분한 활용 가능성을 확인하였다.

• Restorative Dentistry and Endodontics
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• 제25권2호
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• pp.289-298
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• 2000

Carbamide peroxide is usually used for vital teeth bleaching at home. Complications such as tooth hypersensitivity and/or gingival irritation are frequently reported. Therefore, this study was performed to evaluate any possible histological changes in pulp and periodontal tissue by carbamide peroxide bleaching gel in rats. 10% and 15% carbamide peroxide containing nightguard for upper molar were worn for 4 hours a day. The rats were sacrificed after 1 day, 2 days, 3 days, 4 days and 6 days application of carbamide peroxide respectively. The results were as follows : Mild infiltration of inflammatory changes below the junctional epithelium and hyperplasia of epithelium were observed in both 10% and 15% carbamide peroxide treated groups. In all experimental groups, odontoblasts were changed from columnar to cuboidal shape and/or obliterated and the focal loss of predentin was observed in pulp horn. With increasing time of application, these changes were more remarkable, but limited in pulp horn. Inflammatory reactions, vacuolar changes and hyaline degenerations of the pup tissue were also observed in some cases. These results suggested that carbamide peroxide gel used in home bleaching could cause reversible pulpal irritation.