数字光处理成型氮化硅陶瓷牙科种植体的制备及其生物安全性的初步评价

Preparation of silicon nitride ceramic dental implant by digital light processing and preliminary evaluation of its biological safety

背景氮化硅是一种前景广阔的生物植入材料,数字化光处理技术作为一种先进的3D打印技术,同时具备打印精度高和打印速度快的性能,目前尚缺乏数字光处理成型氮化硅作为牙科用植入材料的研究报道。目的使用数字光处理技术制备氮化硅陶瓷牙科种植体,评估其微观结构和机械性能,并初步评价其浸提液对小鼠成纤维细胞L929的影响。方法参考国标GB 30367-2013和GB/T 10700-2006,对数字光处理成型氮化硅陶瓷,采用三点弯曲法测试弯曲强度,单边预裂纹梁法测试断裂韧性,弯曲法测试弹性模量。应用小鼠成纤维细胞L929进行数字光处理成型氮化硅陶瓷浸提液细胞毒性、细胞增殖和细胞活力的检测。结果为了匹配牙槽骨的弹性模量,设计了低弹性模量氮化硅配方体系,数字光处理成型氮化硅陶瓷弹性模量为125 GPa,弯曲强度为243 MPa,断裂韧性为2.6 MPa·m^(1/2)。细胞毒性实验结果显示,在不同浸提液浓度培养下的L929细胞相对存活率均高于80%。活死细胞荧光染色结果显示,浸提液组与对照组活死细胞数量均无统计学差异(P>0.05)。流式结果示浸提液组增殖指数持续增加,细胞周期与对照组相比无统计学差异(P>0.05)。结论数字光处理成型氮化硅陶瓷具有典型的氮化硅微观结构、良好的弹性模量和生物安全性,显示出了作为牙科种植体的临床应用潜力。

Background Silicon nitride is a promising biological implant material.As an advanced 3D printing technology,digital light processing technology has high printing accuracy and fast printing speed.At present,there is still a lack of research reports on digital light processing of silicon nitride as dental implant materials.Objective To study the preparation of silicon nitride dental ceramics by digital light processing technology,evaluate the microstructure and mechanical properties,and preliminarily evaluate its biosafety.Methods According to GB 30367-2013 and GB/T 10700-2006,the bending strength,fracture toughness and elastic modulus of silicon nitride ceramic by digital light processing were tested by three-point bending method,unilateral precracked beam method and bending method,respectively.The cytotoxicity,cell proliferation and cell viability of silicon nitride ceramic extract treated by digital light processing were detected by mouse fibroblast L929.Results The bending strength of silicon nitride formed by digital light treatment was 243 MPa,the fracture toughness was 2.6 MPa·m^(1/2),and the elastic modulus was 125 GPa.The results of cytotoxicity experiments showed that the relative survival rate of L929 cells cultured at different extract concentrations was greater than 80%.Fluorescence staining results of live and dead cells showed that the number of live and dead cells in the extract group had no significant difference with the control group(P>0.05).Flow cytometry results showed that the proliferation index of the extract group continued to increase,and there was no significant difference in cell cycle compared with the control group(P>0.05).Conclusion Digital light processing molded dental silicon nitride ceramics have a typical porous microstructure,good elastic modulus and biosafety,demonstrating the potential for clinical application of dental implant materials.