| β-TCP ceramics have good biocompatibility and excellent osteoconductivity,as a kind of biodegradable substitute materials they are used widely for bone defect reparation in clinical.At present,there are many ways to prepareβ-TCP ceramics, and the products prepared in different ways have different performance.The purpose of this paper was looking for a new material preparation method,and preparing biodegradableβ-TCP ceramics which have a good performance and bioactivity.The tradition preparation method ofβ-TCP ceramics is mixingβ-TCP and BG powder directly with certain ratio(in general,the ratio is 4:1),then,using different forming process taking shape and sintering.Although these ways are more simple and easier to manipulate,but theβ-TCP powers usually agglomerate and grow into a coarse particle in the sintering process,and the cohesion betweenβ-TCP particles and BG is not tightening and uniform after mixingβ-TCP and BG powers,and the materials have a coarse crystal structure and may impact on materials' bioactivity and the induction osteogenesis function;furthermore,silicon is not easy to degrade in vivo,so as an implant material with high content(20wt%) of BG,although it possess cementation and induction osteogenesis function,it may issue in deposition of silicon.In the study,the mixed time and content ofβ-TCP and BG were different from tradition way.Theβ-TCP powder and BG precursor material was mixed in liquid phase in order to preventβ-TCP powders conglobation.The mass ratio ofβ-TCP powder and BG precursor material is 9:1.After that,the mixed material was calcined, formed and sintered.In this experiment,chemical precipitation method was introduced to prepare the precursor ofβ-TCP,which was prepared using aqueous solution of absolute ethanol as solvent and A.R.of calcium and phosphonium as solute. The bioglass was a system of Si-Ca-P-Na BG,which was made by sol-gel method.The result showed that theβ-TCP particle size was the least,about 190nm,when absolute ethanol and deionized water were mixed in volume ratio of 1:1.As a cohesive material,when the content of the BG was 10wt%of the gross mass ofβ-TCP and BG it could exert a good stickiness performance.When the content of pore former,starch:PEG=3:1,was 30wt%of the gross mass,theβ-TCP porous ceramic prepared by slurry casting method had a better porosity through SEM observation and apparent porosity and density of the ceramic was 63.4%and 0.5655 g/cm~3 respectively.Theβ-TCP ceramic samples were tested by XRD after sintered;the main crystal phase of the materials wasβ-TCP in spite of having a bit of other crystal phase.The weight loss ratio of the samples soaked in Ringer solution was a linear relation with time,after soaked for 21d,the mass loss rate reached 13.6wt%.After the samples were soaked in Ringer solution 7d and 14d,the surface structure of materials was observed by 3D video microscope,it shown that the surface structure was modified and changed.The further SEM Observation found there were plentiful superficial outgrowth on the surface,XRD analysis shown that the outgrowth was HA crystal,which indicated that theβ-TCP ceramics prepared by liquid phase mixed method had good bioactivity.It were hoped to qualify as bone tissue engineering material. |
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