Experimental Research Of Foam SiC In Repairing Mandibular Critical-sized Defects Of Rabbits

ObjectiveThe large mandibular defect caused by cancer, trauma or other causes will not only result in the varying degrees of physical deformity and the loss of function, but also cause serious psychological trauma. Because of bone and autologous bone graft have significant deficiencies, the development of cancellous bone with the characteristics of the three-dimensional geometric structure of porous bioactive artificial bone is the area of medical and biological materials for an important job. However, hydroxyapatite (HA), represented by Biomimetic porous material has good biocompatibility and clinical application of a large number of experiments confirmed, but the lack of mechanical properties of HA and weak manufacturing capacity make it difficult to achieve large area and complex shape of the load-bearing bone defect repairing. Silicon carbide (SiC) ,which developed by Institute of Metal Research, Chinese Academy of Sciences has excellent mechanical properties and good processing performance, and pre-experimental results show the biology compatibility of SiC is good. In this experiment, through the establishment of rabbit mandibular critical-sized defect of artificial materials implantation , in order to discuss the practicability of foam SiC using as bone repalacement material for clinic.Metheod1 .The establishment of rabbit mandibular critical-sized defect of artificial materials implantation28 adult Japan rabbits were used in the experiment, a rectangular full-thickness defect with the size of 13mm×6mm×4mm were made at both sides of the mandibular body of 24 of them,then implanted silicon carbide(SiC) at the left side as experimental group and HA at the right side as control group.4 of them make defect at one side only without any materials implanting.2.Draw the materials from rabbitsInjectived tetracycline hydrochloride (25mg/kg) 1 week before Drawn, than draw the materials from rabbits at 4 weeks, 8 weeks, 24 weeks after the opration respectively, the blank control group were drawn at 24 weeks.3. Slicer makingGradient alcohol dehydration, embedded in methyl methacrylate, slice by LEIKASP-1600 slicer, selectted the middle section for fluorescence microscopy and HE staining and toluidine blue staining.4.observationSpecimens obtained were evaluateded with general observation, histological observation and bone histomorphometry.Result28 rabbits were all in good health,and foam SiC had no adverse effects to the process of recovery of bone. The rate of fluorescence labeling and new bone area of foam SiC are smaller than that of HA at 4 weeks,but they have no significant differences at 8 weeks and 24 weeks after inpantation.ConclusionThe effects of foam SiC in repairing mandibular defects are similar with HA after inpantation,so its osteo-conduction is not bad than HA.