| Objective: Dentin matrix is derived from natural teeth and has good biocompatibility,bone induction and bone conduction ability.It is rich in growth factors that can induce new bone formation.Some reports at home and abroad suggest that it can repair bone defect area.However,there is no analysis report on the effect of osteogenesis and its comparison with that of autogenous bone transplantation.The analysis of the osteogenic effect of bone defect is helpful to further understand whether dentin can be a good bone substitute material.Materials and methods:1.Animal selection: Twenty-four healthy three-month-old New Zealand white rabbits,female,weighing 2.4 kg on average,were divided into four groups.Group A autogenous dentin group,group B allogeneic dentin group,group C autogenous bone group,group D blank control group.2.Treatment of dentin: The mandibular incisors of experimental animals were extracted,enamel,cementum,pulp and periodontal ligament were removed,and flaky dentin blocks were made.0.2% chlorhexidine solution was immersed for 10 minutes.3.Animal experiment: After anesthesia,the central part of the cranium was cut to the surface of the skull,and the periosteum was separated.Four cortical bones with a diameter of 8 mm were prepared by implanting machine and annular drill cooling.The autogenous skull was cut and then implanted into the corresponding parts of group A,B and C,leaving blank in group D.Close suture.4.Observing method: Observe the operation area of experimental animals closely after operation.At 4,8 and 12 weeks,select and kill the same number of animals randomly.Observe the healing of the operation area,whether there is inflammation,edema,bleeding and so on.The color change and texture compactness of the implanted materials,their full shape,mobility and fiber wrapping on the surface.The changes of bone volume fraction were observed by micro-CT.Histologically,the number and distribution of inflammatory cells,and the changes of new bone formation per unit area were observed.The results were analyzed by SPSS19.0statistical software.The results obtained had statistical significance when P < 0.05.Result:1.All 24 rabbits survived in good health.Skull wounds healed well.No swelling,exudation and inflammation were observed.The skull specimens showed that all the tissues were covered with fibrous connective tissue,and the tissue was compact.At4,8 and 12 weeks after the operation,the stability of the dental materials increased gradually,and a few dentin materials loosened near the surface.2.Micro-CT showed that there was no obvious absorption of dentin and autogenous bone group,and no complete bone repair in the blank control group.There was no significant difference in bone volume fraction between the three implants(P > 0.05),but there was significant difference between the three implants and the blank control group(P < 0.05).3.Histological observation showed that there were insect-like defects at the dentin margin.New bone formation and adherence to dentin can be seen around dentin.There was no significant difference in the number of inflammatory cells per unit area,the rate of new bone formation per unit area between the three implants(P >0.05).Conclusion:1.Both autologous dentin and allogeneic dentin can induce the formation of new bone,and the quality of new bone formation increases with time.2.There was no obvious rejection after dental allograft implantation,which indicated that dentin had low immunogenicity.3.Compared with autogenous bone,dentin has good bone induction and bone formation ability.Its own decomposition is slow,and it has good biocompatibility.Compared with other bone substitute materials,it is cheaper and easier to obtain.It is an excellent bone substitute material. |
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