Promoting effect of the sub-renal capsule microenvironment on the development of allotransplanted tooth in rats

Objective To explore a suitable culture environment for tissue-engineered teeth and to evaluate the developmental ability of full tooth germs,dental papilla and enamel organ in sub-renal capsule space.Methods Rat fetus at embryonic day 18(ED18) were obtained by Cesarean section.The full first molar germs were separated from fetus,and to separate them further into enamel organ and dental papilla by microsurgery.Subsequently,full tooth germ,enamel organ and dental papilla were transplanted into sub-renal capsule tissue of adult Sprague-Dawley rat by special glass tube and col-lected at 2 weeks after grafting.Paraffin sections were prepared and the histological changes of transplants were examined with HE staining.Results Full tooth germs were well developed into normal shape and structure in the rat sub-renal capsule microenvironment.The dentin-pulp complexes were formed by separated dental papillas.However,the separated enamel organs were not well developed,both tooth crown and enamel were not formed in this group.Conclusions The re-sults of this study indicate that renal subcapsular space is a suitable culture environment for allotransplantated teeth devel-opment.After ED18,enamel organ development is still regulated by signals from dental papilla,but in contrast,dental pa-pilla development is no longer dependent on the signals from enamel organ.