Fig. 4

In vivo cementogenesis of HERS-H1 and HERS-C2. a After 8 weeks of transplantation, there were few cells grown in the control transplants. b Only a dense mass of periodontal ligament fiber-like tissues (f) and fibroblast-like cells were found and there was no mineralized structure formed in HERS-H1 transplants. An abundance of blood vessels was formed among the tissues (black arrow). c Thin layer of cementum-like tissue (red arrow) and some cementoblast-like cells (green arrow) were generated on the surface of hydroxyapatite/tricalcium phosphate (HA/TCP) particles in HERS-C2 transplants. Periodontal ligament fiber-like tissues (f) were observed among the mineralized structure. Immunohistochemistry analysis of the HERS-C2 grafts (f, i, l) showed strong positive staining for DMP1, BSP, and OCN in the cementum-like tissues (red arrow) and the cementoblast-like cells (green arrow), compared to the negative staining with the corresponding antibodies in the control transplants (d, g, j), respectively. In HERS-H1 transplants, e DMP1 was totally negative and (h, k) BSP and OCN were positive in only a few cells (cyan arrow). m Periostin was negative in the control grafts. n, o The fiber-like tissues both in HERS-H1 and HERS-C2 groups were positive for Periostin. p, q, r Negative controls (NC) did not show staining. (HA: HA/TCP particles. Scale bar: 100 μm)