• International Journal of Oral Biology
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• 제46권2호
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• pp.67-73
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• 2021

This study summarizes the recent cutting-edge approaches for dentin regeneration that still do not offer adequate solutions. Tertiary dentin is formed when odontoblasts are directly affected by various stimuli. Recent preclinical studies have reported that stimulation of the Wnt/β-catenin signaling pathway could facilitate the formation of reparative dentin and thereby aid in the structural and functional development of the tertiary dentin. A range of signaling pathways, including the Wnt/β-catenin pathway, is activated when dental tissues are damaged and the pulp is exposed. The application of small molecules for dentin regeneration has been suggested as a drug repositioning approach. This study reviews the role of Wnt signaling in tooth formation, particularly dentin formation and dentin regeneration. In addition, the application of the drug repositioning strategy to facilitate the development of new drugs for dentin regeneration has been discussed in this study.

• Restorative Dentistry and Endodontics
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• 제46권2호
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• pp.17.1-17.9
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• 2021

Objectives: In recent in vitro study, it was reported that osteostatin (OST) has an odontogenic effect and synergistic effect with mineral trioxide aggregate (MTA) in human dental pulp cells. Therefore, the aim of this study was to evaluate whether OST has a synergistic effect with MTA on hard tissue formation in vivo. Materials and Methods: Thirty-two maxillary molars of Spraque-Dawley rats were used in this study. An occlusal cavity was prepared and the exposed pulps were randomly divided into 3 groups: group 1 (control; ProRoot MTA), group 2 (OST 100 μM + ProRoot MTA), group 3 (OST 10 mM + ProRoot MTA). Exposed pulps were capped with each material and cavities were restored with resin modified glass ionomer. The animals were sacrificed after 4 weeks. All harvested teeth were scanned with micro-computed tomography (CT). The samples were prepared and hard tissue formation was evaluated histologically. For immunohistochemical analysis, the specimens were sectioned and incubated with primary antibodies against dentin sialoprotein (DSP). Results: In the micro-CT analysis, it is revealed that OST with ProRoot MTA groups showed more mineralized bridge than the control (p < 0.05). In the H&E staining, it is showed that more quantity of the mineralized dentin bridge was formed in the OST with ProRoot MTA group compared to the control (p < 0.05). In all groups, DSP was expressed in newly formed reparative dentin area. Conclusions: OST can be a supplementary pulp capping material when used with MTA to make synergistic effect in hard tissue formation.

• 대한치과보존학회:학술대회논문집
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• 대한치과보존학회 2001년도 추계학술대회(제116회) 및 13회 Workshop 제3회 한ㆍ일 치과보존학회 공동학술대회 초록집
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• pp.566.1-566
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• 2001

The most desirable healing process for endodontic therapy is apical closure by hard tissue such as dentine or cementum. Then, we estimated hard tissue conductivity of tetracalcium phosphate (4CP)/dicalcium phosphate (2CP) compound using mandibular first molars of SD rats. Residual pulp responses to the calcium phosphate compound were examined at several amputation levels of pulp. 2CP was purchased and passed through a $32-\mu\textrm{m}$ sieve. 4CP was obtained from a stoichiometric mixture of 2CP and calcium carbonate (Mol ratio: Ca/P=2.0) by the dry synthetic method at 1, 400(C for 8 hours.(omitted)

• International Journal of Oral Biology
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• 제48권4호
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• pp.33-44
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• 2023

In this review, the regulatory mechanisms of autophagy were described, and its interaction with apoptosis was identified. The role of autophagy in embryogenesis, tooth development, and cell differentiation were also investigated. Autophagy is regulated by various autophagy-related genes and those related to stress response. Highly active autophagy occurrences have been reported during cell differentiation before implantation after fertilization. Autophagy is involved in energy generation and supplies nutrients during early birth, essential to compensate for their deficient supply from the placenta. The contribution of autophagy during tooth development, such as the shape of the crown and root formation, ivory, and homeostasis in cells, was also observed. Genes control autophagy, and studying the role of autophagy in cell differentiation and development was useful for understanding human aging, illness, and health. In the future, the role of specific mechanisms in the development and differentiation of autophagy may increase the understanding of the pathological mechanisms of disease and development processes and is expected to reduce the treatment of various diseases by modulating the autophagic phenomenon.

• Journal of Periodontal and Implant Science
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• 제52권4호
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• pp.312-324
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• 2022

Purpose: The role of hard-type crosslinked hyaluronic acid (HA) with particulate bone substitutes in bone regeneration for combined inlay-onlay grafts has not been fully investigated. We aimed to evaluate the effect of hard-type crosslinked HA used with bone substitute in terms of new bone formation and space maintenance. Methods: A 15-mm-diameter round defect was formed in the calvaria of 30 New Zealand White rabbits. All animals were randomly assigned to 1 of 3 groups: the control group (spontaneous healing without material, n=10), the biphasic calcium phosphate (BCP) graft group (BCP, n=10), and the BCP graft with HA group (BCP/HA, n=10). The animals were evaluated 4 and 12 weeks after surgery. Half of the animals from each group were sacrificed at 4 and 12 weeks after surgery. Samples were evaluated using micro-computed tomography, histology, and histomorphometry. Results: The BCP group showed higher bone volume/tissue volume (BV/TV) values than the control and BCP/HA groups at both 4 and 12 weeks. The BCP and BCP/HA groups showed higher bone surface/tissue volume (BS/TV) values than the control group at both 4 and 12 weeks. The BCP group showed higher BS/TV values than the control and BCP/HA groups at both 4 and 12 weeks. No statistically significant difference in newly formed bone was found among the 3 groups at 4 weeks. The BCP group showed significantly higher new bone formation than the BCP/HA group at 12 weeks. Conclusions: Hard-type crosslinked HA did not show a positive effect on new bone formation and space maintenance. The negative effect of hard-type crosslinked HA may be due to the physical properties of HA that impede osteogenic potential.

• Journal of Periodontal and Implant Science
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• 제9권1호
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• pp.28.2-28.2
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• 1979

• 대한소아치과학회지
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• 제24권3호
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• pp.518-536
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• 1997

The purpose of the present study was to analyze the pulpal tissue reactions to several capping materials. 8 adult Mongrel dogs and 4 different capping materials (G I : Calcium hydroxide, G II : Bonding resin, G III : Glass ionomer liner, G IV : Bioactive ceramic) we-reused in the study. The results can be summarized as follows : 1. The formation of hard tissue barrier was observed to begin after 2 weeks in all groups with various forms or positions. 2. According to the result of statistical analysis, G I and G IV showed significantly higher degree of inflammation than G II, G III in 1-week samples(p<.05). And in 2-week samples, G I showed higher degree of inflammation than G II, G IV with statistical significance(p<.05). Howere, these inflammatory reactions have gradually dimiished with time resulting in negligible difference between groups. 3. No bacterial penetration was observed in any group. 4. Hard tissue formation was evident in all groups after 2 weeks regardless of material type in this experiment. Conclusion can be drawn from the above-mentioned results that the perfect marginal sealing after pulp capping procedure is thought to be the most important factor in determining the propgnosis of direct pulp capping.

• 구강회복응용과학지
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• 제23권4호
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• pp.303-312
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• 2007

Recently several studies have been developed not only to apply bone materials to bony defect, but also to use osteogenic and osteoinductive materials to form bone more effectively. In 1998 Mark et al applied gel formation of PRP(platelet-rich plasma) in bony transplantation for mandibular reconstruction as one of the method of stimulating bone formation in maxillofacial area, which is contain of varies growth factors. After he reported that PRP accelerate bone formation, which is used in varies bone transplantation and augmentation with a good result. Especially there are amount of growth factors in PRP, and PRP increase angiogenesis, cell division, and mesenchymal cell growth. Moreover it is capable of osteoconduction, hemostatitis, anti-infection, forming the shape at transplantation, ease of handling, and recipient site stability. So it is known that success rate is high in bone transplantation. However PRP need tissue adhesive to make plasma to solid form. Thrombin and calcium chloride, component of PRP, is extracted from autogenic donor. So it is expensive to extract and there is possibility of hepatitis, AIDS, and hematogenous metastasis. After all, tissue adhesive have the limitation and danger of use. So we are willing to introduce that we had get some idea after using PRF(platelet-rich fibrin) in the various hard and soft tissue bony defect, which is self extracted simply and contain growth factors.

• 한국발생생물학회지:발생과생식
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• 제13권2호
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• pp.89-95
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• 2009

p63은 다양한 상피 조직의 줄기세포와 전구세포에 존재한다는 사실이 잘 알려져 있으나, 치아 형성, 특히 사기질과 뿌리 형성시기에서의 p63 위치느 ㄴ아직 연구해야 할 과제로 남아 있다. 본 연구에서는 p63이 치아 발생 동안 치아상피에 편재하여 나타나는 것을 면역조직화학 기법을 이용하여 확인하였다. p63은 피부, 모낭, 구강점막 그리고 턱밑샘 도관을 포함하는 상피의 바닥층과 바닥위층에 위치하였다. 그러나 치아 부위에서는 치아관의 모든 세포, 사기질기관, 헤르트비히 뿌리상피집 그리고 말라세쯔 상피잔사에 p63이 관찰되었다. 이 결과는 치아 발생 중 p63이 줄기세포 유지 외에도 다른 기능을 한다는 사실을 보여준다.

• 대한한방부인과학회지
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• 제25권2호
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• pp.66-77
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• 2012

Objectives: This study was designed to investigate the effects of PR on ovarian tissue in PCOS rats through measurement of morphological and histo-pathological observations, ovarian size. In addition, effects on expression levels of Insulin like Growth Factor Receptor(IGFR) were also investigated to elucidate related mechanisms. Methods: PCOS was induced by single intermuscular injection with ${\beta}$-Estradiol 17-Valerate(EV) in female rats. Normal group(NOR, n=8) were injected with sesame oil and administrated hard food for five weeks. Control group(CTL, n=8) were injected with EV and administrated hard food for five weeks. CR group(n=8) were injected with EV and administrated hard food mixed CR for five weeks. Then, we measured weights of body and ovary, uptakes of food and water. And we observed morphological and histo-pathological changes of ovary, levels of IGFR. Results: In this experiments, single injection of Estradiol Valerate(EV) induced suppression of weight gain, formation of cysts, increase of IGFR expression. Oral administration of PR prevent decrease of ovarian size significantly. Further more, formation of cystic follicles induced by EV injection is suppressed by PR treatment. Conclusions: These results suggest PR can be used for patients with PCOS to prevent formation of cystic follicles and malfunction of ovary.