Regeneration Of Dental Pulp Tissue In Mature Dog Teeth With Apical Periodontitis Using Vascular Endothelial Growth Factor And Bone Morphogenetic Protein2

Objective: Adult apical periodontitis is one of the common disease, the ideal objectives of regenerative endodontic procedures are to regenerate biological function tissue, ideally, the pulp-dentin complex .This research investigate the feasibility of dental pulp regeneration in mature teeth with apical periodontitis on situ using vascular endothelial growth factor (VEGF) and bone morphogenetic protein2 (BMP2) to induce allogeneic bone marrow mesenchymal stem cells or endogenous cells.Methods :1.Bone marrow mesenchymal stem cells(BMMSCs) as donor wereaspirated from baby dog tibia's bone marrow and isolated by the whole bonemarrow adherence method.2.Apical periodontitis model was established in 30 mature anterior teeth of 3 dogs (10-12 months).Then, the root canals were prepared by the enlargement of the apical foramen to 0.3mm in diameter using a Protaper F3.A triple antibiotic pasteconsisting of ciprofloxacin, metronidazole, and minocycline wasthen inserted into each canal.3.After disinfected, the root canals were filled with peptide hydrogel scaffold which was composited with different cytokines and(or) BMMSCs according to the experimental groups: V group (VEGF), VC group (VEGF+BMMSCs),VB group (VEGF+BMP2) ,VBC group (VEGF+BMP2+BMMSCs) , C group(BMMSCs) and a control group (without cytokines and BMMSCs) . Eight weeks after the operation, a histological observation and quantitative analysis was undertaken to evaluate the regeneration tissue in the root canals.Result: 1 .Eight weeks after the operation, newly formed vascularized connective tissue were found in the root canals which filled with VEGF and VEGF+BMP2.No cells and vessels were observed in the root canals in control group. There were hard tissue deposited on the dental wall and monolayer flattened cells adhered the dental wall and some cells are embedded in the hard tissue which was cementoid or bone-like tissue. However, the odontoblasts layer are aligned in a palisade appearance in normal dental pulp tissue.2.Tiny collagenous fibers arranged in disorder were seen in the regenerative tissue and thickcollagenous fibers arranged in the pulp core of normal pulp according to the Masson staining.3.Statistical analysis showed that the ratio of newly regenerated tissue toroot canal surface area was significantly larger in the case of transplantation of VEGF than in the case of transplantation of BMMSCs only ,but it has no statistical significance that different radiobetween in the case of delivery combined VEGF and/ or BMP2 and in the case of delivery combined VEGF and/ or BMP2 with BMMSCs. Interestingly, the new regenerate tissue grew up to the crown of one tooth of VBC group.Conclusion: 1. Dental pulp regeneration in mature teeth with apical periodontitis on situ can be induced by allogeneic BMMSCs.2.VEGF singularly and combinated VEGF and BMP2 can induce cell homing,angiogenesis, and mineralized tissue formation.3.The regenerated tissue grew up to dental crown in the case of delivery combined VEGF?BMP2 and BMMSCs .4. Dental-pulp-like tissue can regenerate by chemotaxis-induced cell homing when the size of the apical foramen are enlargered to 0.3mm, but more studies are needed in the future to test the the optimal size.