Figure 1.

Isolation of SHED. (A) The exfoliated primary incisor contained dental pulp as shown (black triangles). The dashed line shows the occlusion edge of the incisor. (B and C) Hematoxylin/eosin staining indicated dentin (D) and pulp of exfoliated deciduous teeth. The pulp contained odontoblasts (arrows), blood vessels (open arrows), and connective tissues. The straight and curved dashed lines in B represent the occlusion and resorbed root surfaces, respectively. (D) Single colonies were formed after SHED were plated at low density and cultured for 2 weeks. (E) SHED were capable of forming sphere-like clusters when cultured with the conditions described in Materials and Methods. (F) The sphere-like clusters could be dissociated by passage through needles and subsequently grew on 0.1% gelatin-coated dishes. (G) The proliferation rates of SHED, BMSSCs, and DPSCs were assessed by BrdUrd (BrdU) incorporation for 12 h. SHED showed a significantly higher proliferation rate in comparison with BMSSCs and DPSCs (*, P < 0.05, Student's t test). (H) SHED were able to proliferate to >140 population doublings, which was significantly higher (*, P < 0.05, Student's t test) than BMSSCs and DPSCs.