| In this paper,SLA light curing technology was used,and hydroxyapatite with good biocompatibility and tricalcium phosphate with degradable bioactive material were selected.The component design and preparation process optimization of tricalcium phosphate and its multi-phase ceramic paste were carried out β-TCP、β-TCP/HAp ceramic paste forming process,degreasing sintering process parameters,prepared ceramic scaffold materials,and carried out in vitro degradation experiments.This paper has carried out the following three aspects of research.The curing performance of the photosensitive resin system was carried out,the selection of ceramic components was determined,the paste preparation process was optimized,and the paste with good fluidity,dispersion and curing performance was prepared for SLA-3D printing β-TCP、β-TCP/HAp composite ceramic paste.According to the design principle of light curing paste suitable for SLA-3D printing,the curing of photosensitive premixes based on water-based and free radical system was studied respectively.The curing properties of photosensitive premixes and ceramic paste were analyzed,and the component design of photosensitive premixes based on free radical system was determined.According to the principle of the design method of ceramic particles,the ceramic component in the ceramic component is determined as β-TCP,HAp,SiO2 as sintering additive.The preparation process of a photosensitive ceramic paste was optimized,and the ceramic particles were uniformly dispersed in the photosensitive resin system.Based on the analysis of rheological and curing properties of UV curable ceramic paste,the ratio of prepolymer to monomer is 7:3,and the viscosity is 4750 MPa·s and suitable for sla-3d printing β-TCP、β-TCP/HAp ceramic paste.Based on the prepared composite ceramic paste,the light curing forming process and degreasing sintering process were optimized,and the suitable curing forming and degreasing sintering process of composite ceramic paste were proposed.The effect of laser power on the curing properties of β-TCP、β-TCP/HAp ceramic paste was studied,the formula for predicting the curing line thickness of β-TCP、β-TCP/HAp ceramic paste prepared in this study was established.The effect of delamination thickness on the cured parts was studied,and the delamination thickness of SLA-3D printing β-TCP、β-TCP/HAp ceramic paste was determined to be 100 μm.The thermal decomposition stage of the polymer component was analyzed by printing the thermogravimetric curve of the green body of the biological scaffold with SLA-3D,and the debinding process was optimized.The effects of sintering process(maximum sintering temperature and holding time)on the microstructure of ceramic scaffolds were studied,β-TCP、β-TCP/HAP sintering experiments were carried out with different sintering processes respectively.The sintering process of β-TCP ceramic paste is determined as follows:the highest sintering temperature is 1250℃,the holding time is 120min,and the heating rate is 3℃/min;The sintering process of the β-TCP/HAP composite ceramic paste is as follows:the highest sintering temperature is 1300℃,the holding time is 120 min,and the heating rate is 3℃/min.The degradation of ceramic scaffold in vitro was studied.According to the degradation characteristics and bone induction of tricalcium phosphate,a ceramic scaffold was designed for in vitro degradation experiment.The ceramic scaffold withβ-TCP、β-TCP/HAp(the particle size of HAP powder is 15μm)、β-TCP/HAp(the particle size of HAP powder is 20 nm),TCP scaffold was successfully prepared by adopting the optimized component design,curing forming process,debinding process and sintering process.The degradation experiments of the same materials with different structures and the same materials with different components were carried out in vitro.The results show that the degradation weightlessness of ceramic scaffold increases first and then decreases with the increase of degradation time.When the degradation time is 14 days,the degradation weight loss rate reaches the maximum;With the increasing of degradation time,when the degradation time is 21 days,the degradation weight loss rate decreases,and the degradation weight loss rate of 1 mm,1.5 mm and 2 mm wall thickness structure becomes negative;The degradation rate and deposition rate of scaffolds with connected pore structure have little difference.Compared with ceramic scaffold with different material components,the degradation weight loss rate of composite ceramic scaffold with hydroxyapatite was lower than that of pure one The degradation of β-TCP was reduced by weight loss rate and the degradation performance of composite ceramics was reduced;Compared with the sintered ceramic supports,the weight loss rate of degreased parts increased. |
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