Stem Cells from Human Exfoliated Deciduous Teeth in Delayed Tooth Replantation: Histologic and Histomorfometric Analyses in Rats

Aim: The complication in delayed replantation is root resorption that leads to loss of reimplanted teeth. This study was designed to evaluate the influence of stem cells from human exfoliated deciduous teeth (SHEDs) on the healing process of periodontal tissues after delayed tooth replantation in rats.  Material and Methods: Forty-five rats had their right upper incisor extracted and maintained in dry storage for 60 minutes. Then dental papilla was removed; root canal was prepared and filled with calcium hydroxide paste and root surface treatment was processed. Rats were randomly assigned into three groups: Control group: the incisor was replanted without any substance in the dental socket. SHEDs group: the tooth was replanted after infusion of SHED, re-suspended in platelet-rich-fibrin in the dental socket; platelet-rich-fibrin group: the incisor was replanted with platelet-rich-fibrin in the dental socket. Animals were euthanized on days 15, 30 and 60 after replantation; histological and histomorphometric analyses were performed.  Results: Root resorption was present in all experimental groups. No statistically significant differences were observed in the final period of study. The control group showed more replacement resorption but SHEDs group, showed dental tissues were more preserved. Inflammatory resorption nearly did not affect any group, as expected in this protocol (p<0.005). Conclusions: The findings of this study suggest that in the SHEDs group, teeth were more preserved with ankyloses occurrence, witch holds teeth in the socket for a longer period of time, when compared to replacement resorption or inflammatory resorption in the healing process of delayed replantation.