| ObjectiveThe mandibular defects caused by various reasons not only affect the appearance of patients,but also cause a variety of functional impairments,and bring some difficulties for the repair surgery later at the same time.The materials commonly used for repair bone defect are utologous bone,xenograft bone and artificial materials.Taking into account the advantages and disadvantages of various materials,the most widely used is artificial materials.Porous tantalum is a new material used for bone repair in recent years,its excellent mechanical properties and biocompatibility provide good conditions for the repair of bone defects,we have previously proved that porous tantalum particles repair a small range of mandibular defect could achieved a satisfactory result,that indicated the porous tantalum can be used to repair the small-scale restoration of oral and maxillofacial bone defect.However,a variety of growth factors involved in the repair of bone defect process,All kinds of bone repair materials can only provide support for bone growth,and lack of the growth factors that can promote bone formation,this will affect the early revascularization of repair materials.Basic fibroblast growth factor(bFGF)is a growth factor with multiple biological activities,which play an important role in the repair of bone defect.To further explore the factors that can influence the microenvironment when repair of bone defect with porous tantalum pellets,we combined the porous tantalum pellets and bFGF,used the mixed material to repair the canine mandibular defects,and provide the basis for clinical application of porous tantalum combined with growth factor for repairing bone defect.Materials and MethodsSix 12-month-old male beagles were chosen as the subjects,whose first to fourth premolars of both sides were pulled out.After12 weeks normal healing,established 3 diameter 4mm,7mm deep cylindrical bone defects at each side.Three groups were involved: one was the group adopting pure porous tantalum particles as repair material(Porous Tantalum Group);one adopted porous tantalum treated by((bFGF Composite Group);and the non-treated group(Blank Group).After were sacrificed two canines,Two beagles were sacrificed respectively at 4 weeks,8 weeks and 12 weeks.Ten days before the operation,tetracycline fluorescence radioactive labeling was conducted.The experiment specimen went through visual inspection,X-ray detection,toluidine blue staining to Evaluation new bone tissue overall situation,tetracycline immunofluorescence labeling via using Imagepro to calculate each time new bone area percentage,VIII factor related antigen-antibody marker staining for counting the number of blood vessels,and sirius red stain to evaluation the activity.of fiber.Using SPSS16.0 to analyze the data statistical significance.Result1.The beagles grew well and the wound healed well after implantation and showed no inflammation before the experiment specimen was collected.2.X-ray detection each time the porous tantalum particles in porous tantalum group and bFGF composite group are surrounding by bone tissue,no bone resorption showed around the interface of metal and bone tissue.While the the bone defect was not completely healed after 12 weeks3.Toluidine blue staining and Picric acid-Sirius red staining showed that the maturity of new bone tissue in bFGF composite was better than porous tantalum group after 4 and 8 weeks,for the blank group,blue staining area was very little at 4weeks,8 weeks and 12 weeks.4.The result of new bone area analyze indicated after 4 weeks there were larger area of new bone and greater vnumber of the newly formed micro vessels in the combined group than in the porous tantalum group.There was an obvious difference(P<0.05);After 8 weeks,situation reversed(P<0.05);After 12 weeks,no significant difference was found.5.Microvessel counts showed: After 4 weeks larger number of the newly formed micro vessels was found in the combined group than in the other two groups.After 8 weeks the largest number of the newly formed micro vessels was found in the porous tantalum group.no significant difference in the case of vessels at the end of 12 weeks.6.Picric acid Sirius red staining shows bFGF group after 4 weeks the activity of fiber is stronger than porous tantalum group,after 4 weeks and 8 weeks the bone continuity and maturity were better than that of porous tantalum group.Conclusion1.The bone defect established in dogs of this experiment still can not be repaired by themselves at the end of 12 weeks,with a bone substitute in repairing meaningful,it can be used to evaluate the effect of porous tantalum particles when repair bone defect.2.Further validated the biocompatibility of porous tantalum particles in vivo,bone tissues and porous tantalum particles are perforating bound,and the former can grow into the pore.3.The porous tantalum particles after comebine with bFGF can promote cell proliferation and extracellular matrix,promoting early collagen fibers and capillary growth,improving the restorative effects of porous tantalum particles improve bone defect repair speed and shorten bone defect healing time. |
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