• Journal of Periodontal and Implant Science
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• 제38권4호
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• pp.679-690
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• 2008

Purpose: The aim of this study was to investigate the effects of EMD on demineralized root surface using human periodontal ligament cells and compare the effects of root conditioning materials(tetracycline(TCN), EDTA). Material and Methods: Dentin slices were prepared from the extracted teeth and demineralized with TCN and EDTA. Demineralized dentin slices were incubated at culture plate with 25, 50 and $100{\mu}g/ml$ concentration of EMD. Cell attachment, alkaline phosphatase activity test, protein synthesis assay and scanning electronic microscopic examination were done. Results: Cells were attached significantly higher in EMD treated group at 7 and 14 days. Cell numbers were significantly higher in EMD treated group. Alkaline phosphatase activity was significantly higher in EMD treated group at 7 and 14 days. Protein synthesis was significantly higher in EMD treated group at 7 and 14 days. Conclusion: Enamel matrix derivatives enhance the biologic activities of human periodontal ligament cells on demineralized root surface and its effects are dependent on the concentration of EMD.

• 대한치주과학회:학술대회논문집
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• 대한치주과학회 2004년도 제44회 종합학술대회 연제초록
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• pp.119-120
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• 2004

• Journal of Periodontal and Implant Science
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• 제33권3호
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• pp.359-372
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• 2003

Among objectives of periodontal therapy. the principal one is the morphological and functional reconstruction of lost periodontal supporting tissues. This includes de novo formation of connective tissue attachment and the regrowth of alveolar bone. The use of enamel matrix derivative(EMD) may be a suitable means of regeneration new periodontal attachment in the infrabony defects. Implant used to replace lost tooth but, implantitis occurred after installation. The purpose of this study was to investigate the effects of EMD on differentiation and growth of osteoblast in titanium disc. Twentyfive millimeter diameter and 1mm thick Ti disc which was coated 25, 50, 100, 200${\mu}g$/ml of EMD(Emdogain(R)) used as experimental group, 25, 50, 100, 200ng/d of rhBMP-2 as positive control group, and no coat as negative control group. A human osteosarcoma cell line Saos-2 was cultured in Ti disc and cell proliferation and Alkaline phosphatase (ALP) activity were measured at 1 and 6 days. PCR was performed at 2 and 8 hours. Semi-quantitative RT-PCR for mRNA expressions of various osteoblastic differentiation markers -type I collagen, ALP, osteopontin, and bone sialoprotein - were performed at appropriate concentrations based upon the results of MTT and ALP assay. Cultured cell-disc complexes were prepared for scanning electron microscopy (SEM) at 2 hour. Data were analyzed using Mann-Whitney and repeated- measures 1-way analysis of variance(SPSS software version 10,SPSS. Chicago. IL). After culture, there was more osteoblast in EMD100${\mu}g$/ml than in EMD50, 200${\mu}g$/ml on day 6. There was significant difference in experimental and positive control group compared control group, as times go by(1 and 6 days). Alkaline phosphatase activity was different significantly in EMD100, 200${\mu}g$/ml and BMP100, 200${\mu}g$/ml on day 6. The results of reverse transcriptase-polymerase chain reaction (RT-PCR) showed that expression of mRNA for ALPase, collagen type I, osteopontin. hone sialoprotein and BMP-2 was detected at 2 hour and 8 hour in EMI 200${\mu}g$/ml subgroup and BMP100ng/ml subgroup. The results of this study suggest that application of enamel matrix derivative on osteoblast attached to titanium surface facilitate the expression of bone specific protein and the differentiation and growth of osteoblast.

• 치위생과학회지
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• 제12권5호
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• pp.486-492
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• 2012

치아 발생 동안 법랑질모세포에서의 Dynamin II 단백질 발현 강도는 출생 후 1일째 생쥐에 비해 출생 후 3일째와 출생 후 5일째 생쥐에서 각각 48%와 50%로 유의성 있게 증가하였으나, 출생 후 7일째와 출생 후 10일째 생쥐에서는 출생후 1일째의 생쥐에 비해 각각 16%와 12%로 유의성 있게 감소하였다. 이 결과로부터 Dynamin II가 분비법랑질모세포에서 형성되는 법랑기질 단백질인 amelogenin, ameloblastin, enamelin과 MMP-20 등과의 분비과립 수송에 연관됨이 보여졌다. Dynamin II는 치아 발생과정 중 발현되는 다양한 법랑기질을 구성하는 단백질을 포함하는 분비소포 형성을 촉진함으로써 과립의 수송에 관여할 것이라 생각되며 법랑질모세포에서의 법랑기질 단백질의 분비조절 가능성이 있음이 보여졌다. 따라서 Dynamin II를 통한 치주질환을 위한 유전자 치료와 법랑질 혹은 상아질의 유실 부분의 재생산의 자극과 촉진에도 임상적으로 사용될 수 있는 가능성이 있음이 보여졌다.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제35권2호
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• pp.73-81
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• 2013

Purpose: Smad4 is a central mediator for transforming growth factor-${\beta}$/bone morphogenetic protein ($TGF-{\beta}/BMP$) signals, which are involved in regulating cranial neural crest cell formation, migration, proliferation, and fate determination. Accumulated evidences indicate that $TGF-{\beta}/BMP$ signaling plays key roles in the early tooth morphogenesis. However, their roles in the late tooth formation, such as cellular differentiation and matrix formation are not clearly understood. The objective of this study is to understand the roles of Smad4 in vivo during enamel and dentin formation through tissue-specific inactivation of Smad4. Methods: We generated and analyzed mice with dental epithelium-specific inactivation of the Smad4 gene (K14-Cre:$Smad4^{fl/fl}$) and dental mesenchyme-specific inactivation of Smad4 gene (Osr2Ires-Cre:$Smad4^{fl/fl}$). Results: In the tooth germs of K14-Cre:$Smad4^{fl/fl}$, ameloblast differentiation was not detectable in inner enamel epithelial cells, however, dentin-like structure was formed in dental mesenchymal cells. In the tooth germs of Osr2Ires-Cre:$Smad4^{fl/fl}$ mice, ameloblasts were normally differentiated from inner enamel epithelial cells. Interestingly, we found that bone-like structures, with cellular inclusion, were formed in the dentin region of Osr2Ires-Cre:$Smad4^{fl/fl}$ mice. Conclusion: Taken together, our study demonstrates that Smad4 plays a crucial role in regulating ameloblast and odontoblast differentiation, as well as in regulating epithelial-mesenchymal interactions during tooth development.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제31권4호
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• pp.281-286
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• 2009

Introduction: Enamel matrix derivative (EMD) is a protein which is secreted by Hertwig root sheath and plays a major role in the formation of cementum and attachment of peridontium. Several studies have shown that EMD promoted the proliferation and differentiation of preosteoblasts, osteoblasts and periodontal ligament cells in vitro: however, reports showing the inhibition of osteogenic differentiation by EMD also existed. This study was designed to simultaneously evaluate the effect of EMD on the two cell lines (human mesenchymal stem cells: hMSC, human periodontal ligament derived fibroblasts: hPDLCs) by means of quantitative analysis of some bone related matrices (Alkaline phosphatase : ALP, osteopontin ; OPN, osteocalcin ; OC). Materials and Methods: hMSCs and hPDLCs were expanded and cells in the 4${\sim}$6 passages were adopted to use. hMSc and hPDLCs were cultured during 1,2,7, and 14 days with 0, 50 and 100 ${\mu}g/ml$ of EMD, respectively. ALP activity was assessed by SensoLyte ALP kit and expressed as values of the relative optical density. Among the matrix proteins of the bony tissue, OC and OPN were assessed and quantification of these proteins was evaluated by means of human OC immunoassay kit and human OPN assay kit, respectively. Results: ALP activity maintained without EMD at $1,2^{nd}$ day. The activity increased at $7^{th}$ day but decreased at $14^{th}$ day. EMD increased the activity at $14^{th}$ day in the hPDLCs culture. In the hMSCs, rapid decrease was noted in $7^{th}$ and $14^{th}$ days without regard to EMD concentrations. Regarding the OPN synthesis in hPDLCs, marked decrease of OPN was noted after EMD application. Gradual decrease tendency of OPN was shown over time. In hMSCs, marked decrease of OPN was also noted after EMD application. Overall concentration of OPN was relatively consistent over time than that in hPDLCs. Regarding the OC synthesis, in both of hPDLCs and hMSCs, inhibition of OC formation was noted after EMD application in the early stages but EMD exerted minimal effect at the later stages. Conclusion: In this experimental condition, EMD seemed to play an inhibitory role during the differentiation of hMSCs and hPDLCs in the context of OC and OPN formation. In the periodontium, there are many kinds of cells contributing to the regeneration of oral tissue. EMD enhanced ALP activity in hPDLCs rather than in hMSCs and this may imply that EMD has a positive effect on the differentiation of cementoblasts compared with the effect on hMSCs. The result of our research was consistent with recent studies in which the authors showed the inhibitory effect of EMD in terms of the differentiation of mineral colony forming cells in vitro. This in vitro study may not stand for all the charateristics of EMD; thus, further studies involving many other bone matrices and cellular attachment will be necessary.

• Restorative Dentistry and Endodontics
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• 제31권6호
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• pp.437-444
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• 2006

본 연구에서는 법랑모세포 분화와 법랑질 형성에 연관이 있는 OD314 일명 Apin protein의 기능을 밝힐 목적으로, in-situ hybridization에 의한 OD314 mRNA 발현과 법랑모세포 세포주에서 OD314와 enamel matrix protein의 발현, 그리고 OD314 유전자를 과발현/억제시킬 수 있는 construct를 제작한 후 법랑질 형성 중에 OD314의 기능을 알아보고자 RT-PCR를 시행하여 다음과 같은 결과를 얻었다. 1. OD314 mRNA는 발생중인 상아모세포보다 법랑모세포에서 강하게 발현되었다. 2. Tuftelin은 석회화 결정이 형성되는 14일까지 발현이 지속되고, 그 이후부터 점차 감소하였다. Amelogenin과 enamelin은 7일부터 그 발현이 점점 감소하였다. 3. U6-OD314 siRNA construct를 이용하여 transfection한 법랑모세포 세포주는 OD314와 tuftelin, MMP20 mRNA 발현이 감소하였으며, CMV-OD3l4를 transfection하여 OD314의 과발현을 유도한 경우에는 OD3l4와 MMP20 mRNA의 발현이 뚜렷이 증대되었다. 이 결과는 OD314가 법랑모세포의 분화와 법랑질의 형성 그리고 석회화 과정에 중요한 역할을 하는 새로운 인자임을 시사한다.

• Restorative Dentistry and Endodontics
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• 제44권3호
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• pp.32.1-32.13
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• 2019

Calcium hydroxide (CH) is the gold-standard intracanal dressing for teeth subjected to traumatic avulsion. A common complication after the replantation of avulsed teeth is root resorption (RR). The current review was conducted to compare the effect of CH with that of other intracanal medications and filling materials on inflammatory RR and replacement RR (ankylosis) in replanted teeth. The PubMed and Scopus databases were searched through June 2018 using specific keywords related to the title of the present article. The materials that were compared to CH were in 2 categories: 1) mineral trioxide aggregate (MTA) and endodontic sealers as permanent filling materials for single-visit treatment, and 2) Ledermix, bisphosphonates, acetazolamide, indomethacin, gallium nitrate, and enamel matrix-derived protein (Emdogain) as intracanal medicaments for multiple-visit management of avulsed teeth prior to the final obturation. MTA can be used as a single-visit root filling material; however, there are limited data on its efficacy due to a lack of clinical trials. Ledermix and acetazolamide were comparable to CH in reducing RR. Emdogain seems to be an interesting material, but the data supporting its use as an intracanal medication remain very limited. The conclusions drawn in this study were limited by the insufficiency of clinical trials.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제30권5호
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• pp.438-443
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• 2004

Objectives : The proper development of the facial structures relies upon a sequence of tightly regulated signaling interactions between the ectoderm and mesoderm involving the participation of several families of signaling molecules. Among these, bone morphogenetic proteins (BMPs) have been suggested to be a key signal that regulates the development of the mandible and the initiation and morphogenesis of the teeth. The aim of this study was to examine the artificial development of the mandibular structures and to examine the role of BMPs on tooth morphogenesis and differentiation using an organ culture system. Materials and Methods : The tooth germs from Ed 11.5, 13.5 mice were dissected, and transplanted into the diastema of the mandible primordia. The mandibles containing the transplanted tooth germs were cultured in vitro. During this period, beads soaked with BMP4 were implanted around the transplanted tooth germs. In addition, a diastema block containing the transplanted tooth germ was dissected, then transferred to an adult mouse kidney. After the organ culture, the developing mandibular explant was removed from the kidney and prepared for the tissue specimens. Odontogeneis of the transplanted tooth germs was examined after Hematoxylin-eosin, Masson-trichrome staining. Results : Proliferation and differentiation of the tooth germs cultured in the diastema was observed. In the BMP4-treated tooth germs, the formation of the first and second molars was noted. The crown of the developing tooth showed the formation of a mature cusp with the deposition of enamel and dentin matrix. In conclusion, it was confirmed that BMP4 is involved in the formation of a dental crown and the differentiation of ameloblasts and odontoblasts of the molar tooth during the development of the transplanted tooth germs.

• 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.