Methods: Lower first molars from DDY mice embryos at E 14 were used in this study. Biodegradable PGA scaffolds with a round shape were fabricated, seeded with dissociated the first molars cells, and implanted into the subcapsular layer of kidney in an adult mouse where they allowed to develop over 5, 7, 10, 14, 21 and 28 days, respectively.
Results: Specimens were stained with hematoxylin-eosin in order to observe the extent of tooth morphogenesis after implantation. Histological analysis of 10-day implants revealed tooth-shaped tissue within implants, similar in appearance to that of a tooth bud. Mineralized dentin and pre-dentin layer were apparent, adjacent to odontoblast-like cells. At higher magnification, putative odontoblasts were visible lining the inner surface of a predentine matrix. There was also a bony structure around the tissue-engineered tooth. Histological analysis of 14-day implant tissue revealed tooth tissue with dimensions of approximately 0.5 by 0.5 mm, similar in appearance to shape of a tooth crown. Numerous columnar cells possessing polarized nuclei that are characteristic of ameloblasts were present adjacent to the enamel. At 21 days after implantation, tissue closely resembling decalcified enamel was observed adjacent to dentin, of the kind found in normally developing teeth. We are currently performing immunohistological analysis of these tissues.
Conclusion: In this report, we present morphological, histological analyses characterizing tissue-engineered tooth generated by seeding dissociated mouse tooth bud cells onto biodegradable PGA scaffolds. These analyses demonstrate the successful regeneration of recognizable mouse tooth structures.