| Project/Area Number |
14571727
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Morphological basic dentistry
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| Research Institution | NIIGATA UNIVERSITY |
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Principal Investigator |
OHSHIMA Hayato NIIGATA UNIVERSITY, Graduate School of Medical and Dental Sciences, Professor, 大学院・医歯学総合研究科, 教授 (70251824)
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| Co-Investigator(Kenkyū-buntansha) |
SATO Takuichi Tohoku University, Graduate School of Dentistry, Lecturer, 大学院・歯学研究科, 講師 (10303132)
FUJII Noritaka NIIGATA UNIVERSITY, Graduate School of Medical and Dental Sciences, Assistant, 大学院・医歯学総合研究科, 助手 (90313527)
NAKAKURA Kuniko (OHSHIMA Kuniko) NIIGATA UNIVERSITY, Medical and Dental Hospital, Lecturer, 医歯学総合病院, 講師 (80213693)
MAEDA Takeyasu NIIGATA UNIVERSITY, Graduate School of Medical and Dental Sciences, Professor, 大学院・医歯学総合研究科, 教授 (40183941)
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| Project Period (FY) |
2002 – 2003
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| Project Status |
Completed (Fiscal Year 2003)
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| Budget Amount *help |
¥3,000,000 (Direct Cost: ¥3,000,000)
Fiscal Year 2003: ¥800,000 (Direct Cost: ¥800,000)
Fiscal Year 2002: ¥2,200,000 (Direct Cost: ¥2,200,000)
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| Keywords | Dental Pulp / Regeneration / Low Molecular Weight Heat Shock Protein / Antigen-presenting cells / Cavity Preparation / Replantation / Odontoblasts / Immunohistochemistry / 低分子熱ショック蛋白Hsp25 |
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| Research Abstract |
The purpose of the present study was to clarify the relationship between the chronological changes of immunocompetent cells and the expression of heat shock protein(Hsp) 25 in the process of pulpal regeneration after tooth injury in rat molars by immunocytochemistry for Hsp 25 and class II major histocompatibility complex(MHC) antigen. An intense Hsp 25-immunoreactivity was found in the differentiated odontoblasts. Both cavity preparation and tooth replantation caused the degeneration of the odontoblast layer to result in the loss of Hsp 25-immunoreactions in the suffered dental pulp at the early stages after tooth injury. Numerous class II MHC-positive cells appeared along the pulp-dentin border and extend their cell processes into the dentinal tubules at 12-24 hours after cavity preparation and 3 days after tooth replantation. Newly differentiated odontoblast-like cells with Hsp 25-immunoreactivity were arranged at the pulp-dentin border, and the class II MHC-positive cells retreated
… More
towards the subodontoblastic layer by postoperative 3-5 days after tooth injury. Thus, the common cellular events occur during pulpal regeneration following two different experimental injuries. These findings indicate that the time course of changes in the expression of Hsp 25-immunoreactivity reflects the degeneration/regeneration process of odontoblasts and that the temporal appearance of the class II MHC-positive cells at the pulp-dentin border suggests their participation in odontoblast differentiation as well as in initial defense reactions during the pulpal regeneration process. In the case of laser ablation, on the other hand, distinct abscess formation consisting of polymorphonuclear leukocytes was found in the dental pulp by 3-5 days postoperation. The penetration of masses of oral bacteria was recognizable in the dentinal tubules beneath the prepared cavity. These findings indicate that cavity preparation by laser ablation induces remarkable inflammation by continuous bacterial infections via dentinal tubules. Less
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