RESUMO
PURPOSE: The purpose of this project was to compare alveolar bone repair by allogeneic mesenchymal stem cells using bioglass or synthetic hydroxyapatite (HA)/tricalcium phosphate (TCP) granular scaffolds delivered in a thermoplastic polymeric carrier. MATERIALS AND METHODS: Canine mesenchymal stem cells were obtained from iliac crest bone marrow of beagle dogs and expanded without differentiation. Cells were resuspended at a final concentration of 5 x 10(6) cells/ml in a thermoplastic polymeric carrier (30% w/v Pluronic F-127) and mixed with an equal volume of synthetic HA/TCP or bioglass scaffold and placed into surgically created 5 mm cylindrical defects in the edentulous premolar region of beagle dogs. After 4 weeks or 7 weeks, tissue healing was evaluated by standard histomorphometric methods (Bioquant Nova, Bioquant Image Analysis Corporation, Nashville, TN) by measurement of bone formation within five random sites from each biopsy. RESULTS: After 4 weeks, sites treated with or without mesenchymal stem cells contained 58.25 +/-18.43% or 43.35 +/- 17.68% bone area (p= 0.049), respectively. After 7 weeks, sites treated with or without mesenchymal stem cells contained 62.73 +/- 19.10% or 60.39 +/- 21.32% bone area. Bone formation occurred without inflammation in defects treated using Pluronic F-127 carrier with and without mesenchymal stem cells. There was no difference in percent bone area when bioglass or HA/TCP scaffolds were compared at either time point. CONCLUSIONS: The thermoplastic polymeric carrier did not limit alveolar bone repair in the canine mandible. The combination of a thermoplastic, viscous carrier with a granular scaffold allowed for the delivery of allogeneic mesenchymal stem cells in a clinically manageable form that enhanced bone formation at early stages of alveolar repair.