Experimental Study Of The Repair Of Peri-implant Bone Defect With The Bone Marrow Aspirate Concentrate

Objective: To observe the ability to induce bone regeneration of the bone marrowaspirate concentrate(BMAC) in peri-implant bone defect and evaluate the feasibility ofthe clinical application of BMAC.Methods: The mandibular premolar from12healthy adult dogs of12-18monthold were extracted after anesthesia, and the implants were implanted3months later. Weaspirate the autologous bone marrow(ABM) to get the BMAC before the implantation,and then we implant after the peri-implant bone defect was preparaed. All of theimplants were divided into BMAC、AB(Autologous bone, AB)、AGS(Absorbablegelatin sponge, AGS). The animals were sacrificed after4weeks(α) and12weeks(β).The BMAC was evaluated and analyzed by cytology, and the samples were evaluatedand analyzed by Gross observation, and histological observation.Results:1.Gross observation:3implants(1of the BMAC,1of the AB,1of the AGS) of thetotal48implants disappeared. The other implants have no clinical mobility, percussionsound crisp and no postoperative inflammation.2. Cytology: The pre-concentrated and concentrated of the white blood cellconcentration were （41.50±10.92）×10~9/L and（114.41±27.61）×109/L, and theconcentration ratio was2.78±0.22.The adherent cells were observed at3days, and the colony-forming units (CFU)were observed at7days.2.7/cm~2CFU which contain20-40cells was observed in theBMAC at7d, and2.6/cm~2CFU which contain20-40cells was observed in the ABM at7d.2.4/cm~2CFU which contain20-40cells and3.8/cm~2CFU which contain40andmore cells were observed in the BMAC at11d, and1.4/cm~2CFU which contain20-40cells and2.0/cm~2CFU which contain40and more cells were observed in the ABM at 11d.3. Histological observation: New bone was observed in the three experimentalgroups at4w and12w.The new bone formation rate at4w:BMAC:23.89％±2.93％，AB：14.29％±2.52％，AGS：7.47％±1.18％.The new bone mineral density at4w:BMAC：35.99％±8.08％，AB：26.75％±7.79％，AGS：15.34％±11.10％The new bone formation rate at12w:BMAC：27.92％±9.62％，AB：52.49％±2.89％，AGS：20.15％±1.34％The new bone mineral density at12w:BMAC：48.45％±21.24％，AB：52.10％±13.02％，AGS：53.70％±28.11％Conclusions:1. The high concentration of BMAC could be obtained by manual separation afterthe ABM was centrifuged.2. BMAC could improve the bone regeneration of the peri-implant bone defect.3. BMAC may add the quality and the quantity of the new bone regeneration,however the quantity of the new bone could be reduced with the completion of boneremodeling.