Association of Dental Pulp Stem Cells and Ricinus Bone Compound in a Model of Bone Defect

Abstract

Autogenous bone grafting is needed in some bone tissue defects; however, it causes secondary surgical wounds and morbidity. Tissue bioengineering may be an alternative approach for bone regeneration. Here we investigated the osteogenic potential of dental pulp stem cells from deciduous teeth (DPSC) in association with a Ricinus bone compound (RBC) in a model of bone defect. The influence of the biomaterial RBC on the proliferation and osteogenic differentiation of DPSC was assessed in vitro by MTT metabolism and alizarin red staining, respectively. The morphologic analysis was performed using the optic and scanning electron (SEM) microscopies. For the in vivo study, 54 Wistar rats submitted to calvarial defects were filled with RBC or RBC+DPSC. A control group had the defects filled only with blood clots. Analyses were performed 15, 30 and 60 days after treatment using digital radiography, optical microscopy, SEM and chemical analysis by electron dispersive spectroscopy. The Ricinus bone compound (RBC) did not inhibit the osteogenic differentiation in vitro. No spontaneous regeneration was observed in the control group. The area of the calvarial defect of the RBC+DPSC group showed greater radiopacity on day 15. The RBC presented no reabsorption, was biocompatible and showed osteointegration, working as a mechanical filling. Only sparse ossification areas were found and those were larger and more developed on the RBC+DPSC group when compared to animals treated only with RBC. RBC in association with DPSC is a promising combination for applications in bone regeneration.