Project/Area Number |
12671765
|
Research Category |
Grant-in-Aid for Scientific Research (C)
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Allocation Type | Single-year Grants |
Section | 一般 |
Research Field |
Morphological basic dentistry
|
Research Institution | Niigata University |
Principal Investigator |
OHSHIMA Hayato Graduate School of Medical and Dental Sciences, Niigata University, Professor, 大学院・医歯学部総合研究科, 教授 (70251824)
|
Co-Investigator(Kenkyū-buntansha) |
SATO Takuichi Tohoku University, Graduate School of Dentistry, Assistant, 大学院・歯学研究科, 助手 (10303132)
KAWANO Yoshiro Graduate School of Medical and Dental Sciences, Niigata University, Assistant, 大学院・医歯学部総合研究科, 助手 (60303129)
MAEDA Takeyasu Graduate School of Medical and Dental Sciences, Niigata University, Professor, 大学院・医歯学部総合研究科, 教授 (40183941)
|
Project Period (FY) |
2000 – 2001
|
Project Status |
Completed (Fiscal Year 2001)
|
Budget Amount *help |
¥3,900,000 (Direct Cost: ¥3,900,000)
Fiscal Year 2001: ¥900,000 (Direct Cost: ¥900,000)
Fiscal Year 2000: ¥3,000,000 (Direct Cost: ¥3,000,000)
|
Keywords | Heat shock protein (Hsp) 25 / 27 / Dental pulp / Odontoblasts / Tooth replantation / Cavity preparation / Tooth development / Regeneration / Rat / 象牙質形成 / ラット |
Research Abstract |
The present study aims to clarify the functional significance of heat shock protein (Hsp) 25/27 during tooth development and pulpal regeneration. The present study demonstrated that Hsp 25/27 was expressed exclusively in fully-differentiated odontoblasts during tooth development. For the observation of pulp regeneration, Wistar rats, 4-week-old and 100-day-old, were used for tooth replantation and cavity preparation, respectively. Cavity preparation caused an edematous reaction between the injured odontoblasts and predentin, but the immunoreaction for Hsp 25/27 remained in the injured odontoblasts. Subsequently, Hsp 25/27-immunoreactivity disappeared in the degenerated odontoblast layer after 12 hours. On postoperative 3 days, newly differentiated odontoblasts replaced the degenerated odontoblasts, and became to exhibit the immunoreaction for Hsp 25/27. Tooth replantation also caused the disappearance of Hsp 25/27-immunopositive cells at the initial stages. On postoperative 5days, plump cells with clear nucleoli at the dentin-pulp border became to show Hsp 25/27-immureactivity. These findings indicate that newly differentiated odontoblasts acquire the immunoreaction for Hsp 25/27 in the regenerated pulpal tissue after both cavity preparation and tooth replantation. There was no Hsp 25/27-immunopositive cell along the pulp-dentin border in the case of bone-like tissue formation in the pulp space following tooth replatation. Thus, the alignment of Hsp 25/27-immunopostive cells along the pulp-dentin border is suggestive of the decisive factor to induce the reparative dentin formation after tooth replantation.
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