Formation of dentinal bridge on surface of regenerated dental pulp in dentin defects by controlled release of fibroblast growth factor-2 from gelatin hydrogels.
BACKGROUND
Pulp regeneration therapy is important to overcome the limitations of conventional therapy to induce reparative dentinogenesis. In the present study, we examined the effects of controlled release of different dosages of fibroblast growth factor-2 (FGF-2) from gelatin hydrogels to regenerate the dentin-pulp complex.


METHODS
After the amputation of dental pulp of rat molars, gelatin hydrogels incorporating various dosages of FGF-2 were individually implanted into dentin defects above the sites of the amputated pulps. Histologic changes as well as the expression of dentin matrix protein-1 (DMP-1) and nestin in the dentin defect area above the amputated pulp were analyzed.


RESULTS
We found that controlled release of high doses of FGF-2 from gelatin hydrogels induced DMP-1-positive calcified particles in the proliferating pulp, whereas a moderate dose of FGF-2 induced DMP-1-positive dentinal bridge on the surface of the proliferating pulp. These findings indicate that the dosage of released FGF-2 has an influence on the structure of calcified tissue regenerated in dentin defects. In addition, pulp cells near calcified tissues regenerated in dentin defects were nestin-negative, suggesting that the calcified tissues might be osteodentin.


CONCLUSIONS
Our results showed that the dentin regeneration on amputated pulp, not reparative dentin formation toward amputated pulp, can be regulated by adjusting the dosage of FGF-2 incorporated in biodegradable gelatin hydrogels.
Ishimatsu
Hirotaka
H
Division of Pulp Biology, Operative Dentistry, and Endodontics, Department of Cariology and Periodontology, Kyushu Dental College, Kitakyushu, Japan.
Kitamura
Chiaki
C
Morotomi
Takahiko
T
Tabata
Yasuhiko
Y
Nishihara
Tatsuji
T
Chen
Ker-Kong
KK
Terashita
Masamichi
M
D000818:Animals; D002113:Calcification, Physiologic / Q000187:drug effects; D003782:Dental Pulp / Q000187:drug effects* / Q000378:metabolism / Q000502:physiology; D003789:Dental Pulp Exposure; D003804:Dentin / Q000187:drug effects* / Q000378:metabolism / Q000502:physiology; D003809:Dentin, Secondary / Q000254:growth & development / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D004337:Drug Carriers; D016326:Extracellular Matrix Proteins / Q000096:biosynthesis; D016222:Fibroblast Growth Factor 2 / Q000008:administration & dosage / Q000494:pharmacology*; D020100:Hydrogels; D007381:Intermediate Filament Proteins / Q000096:biosynthesis; D008863:Microspheres; D009419:Nerve Tissue Proteins / Q000096:biosynthesis; D064231:Nestin; D010750:Phosphoproteins / Q000096:biosynthesis; D051381:Rats; D017208:Rats, Wistar; D012038:Regeneration / Q000187:drug effects* / Q000502:physiology; D013047:Specific Pathogen-Free Organisms
C081635:Dmp1 protein, rat; D004337:Drug Carriers; D016326:Extracellular Matrix Proteins; D020100:Hydrogels; D007381:Intermediate Filament Proteins; D009419:Nerve Tissue Proteins; C577486:Nes protein, rat; D064231:Nestin; D010750:Phosphoproteins; D016222:Fibroblast Growth Factor 2