Experimental formation of dentin-like structure in the root canal implant model using cryopreserved swine dental pulp progenitor cells.
OBJECTIVE
The purpose of the present study was to present histological and immunohistochemical evidence showing the regenerative capacity of swine dental pulp stem cells (S-DPSCs) seeded on organic or synthetic scaffolds and implanted as hybrid root implants in the jaw bone of minipigs.


METHODS
Immature permanent incisor teeth and unerupted premolars at the early root-forming stage were extracted from three 7-month-old minipigs, and mesenchymal stem/progenitor cells were isolated from dental pulp. Cells were cryopreserved in liquid nitrogen. A year later, new permanent incisor and premolar teeth were extracted; pulp tissue was removed; and pieces of root canals of the extracted teeth, containing collagen or Poly(lactic-co-glycolic acid) scaffolds seeded with the autologous cryopreserved DPSCs, were implanted into the fresh post-extraction socket of the mini pig jaw. The resulting constructs were harvested after 6 and 10 weeks and evaluated by histological and immunohistochemical analyses.


RESULTS
Six weeks postoperatively, the central canal space of the root implants showed degrading scaffold material. New extracellular matrix had been deposited in a polar predentin-like pattern on the canal dentinal walls by cuboidal nonpolarized cells. Ten weeks postoperatively, newly formed organic matrix had been consistently deposited on the canal walls. The presence of a continuous layer of polarized cells showing typical columnar morphology adjacent to the newly deposited organic matrix was evident.


CONCLUSIONS
The interactions of S-DPSCs with the dentin matrix of roots implanted in the jawbone of minipigs constitute a model to study in vivo organization and differentiation potential of DPSCs.
Department of Endodontology, School of Dentistry, Aristotle University of Thessaloniki, Thessaloniki, Greece. kkodonas@dent.auth.gr
Kostas
K
Kodonas
Christos
C
Gogos
Serafim
S
Papadimitriou
Kokona
K
Kouzi-Koliakou
Dimitrios
D
Tziafas
D000818:Animals; D002454:Cell Differentiation; D003094:Collagen; D015925:Cryopreservation; D003782:Dental Pulp / Q000166:cytology*; D003786:Dental Pulp Cavity / Q000502:physiology*; D003804:Dentin / Q000502:physiology*; D005109:Extracellular Matrix / Q000502:physiology; D019344:Lactic Acid; D045164:Mesenchymal Stem Cell Transplantation; D059630:Mesenchymal Stem Cells / Q000166:cytology*; D023421:Models, Animal; D011100:Polyglycolic Acid; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D012038:Regeneration; D013552:Swine; D013556:Swine, Miniature; D023822:Tissue Engineering / Q000379:methods*; D054457:Tissue Scaffolds; D014092:Tooth Root / Q000502:physiology; D020390:Tooth Socket / Q000601:surgery
C059821:atelocollagen; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011100:Polyglycolic Acid; D019344:Lactic Acid; D003094:Collagen