Mandibular Bone Regeneration with Rat Dental Pulp Stem Cells

Objectives: The need to treat mandibular bone defects is an important issue that motivate researchers to investigate the use of biomaterials, bone substitutes, and added elements that aim to promote bone regeneration. This study investigates the effect of introducing dental pulp stem cells (DPSCs) to the bone regeneration process.
Methods: 40 male Wistar rats (350 gr), in which critical bone defects, 5 mm in diameter, in the angle of right jaw.
Distributed in 4 groups: Group 1: SHAM; Group 2: bone defect with OsteoBiol® bone membrane; Group 3: bone defect with membrane OsteoBiol and bone substitute Tecnoss® Osteobiol®. Group 4: bone defect with membrane OsteoBiol plus bone substitute Tecnoss® Osteobiol® and DPSCs.
Sacrificed 3 and 6 months after surgery, radiological study (CT), histology and the variables calcitonin, PTH, endoglin, TGFβ1 and Collagen-1α2.
Results: Radiographic and histologic observation of the group 2, showed isolation of the area acting like an effective barrier excluding the non-osteogenic tissues and appearing a repair by fibrous tissue. Group 3, no bone formation is shown, the particles of the biomaterial appeared occupying the defect. Group 4 showed a complete bone regeneration of the defect at 6 months. As a marker of neovascularization, we studied endoglin essential for signaling TGF-β in endothelial cells and results showed group 4, a significant increase (p<0.0005) in both the expression of endoglin and in production of growth factors like TGFβ1, a powerful stimulator of bone formation, enhancing osteoblastic differentiation and synthesis of osteoid matrix. In relation to calciotropic hormones (parathormone and calcitonin) our results showed a significant increase (p<0.0005) in the DPSC group, stimulating osteogenesis and collagen constitutive protein of bone matrix.
Conclusions: All biological actions observed show that bone regeneration was significantly higher in the defects with rat dental pulp stem cells (DPSCs), compared with other experimental groups.