三维打印技术制备多孔羟基磷灰石植入体的实验研究

3D printing of porous hydroxyapatite implant

目的评价三维打印成型技术(3DP)制备多孔羟基磷灰石(HA)植入体的可行性,并对烧结体进行微观结构观察及抗压强度评价,为多孔植入体的个性化制作提供实验依据。方法设计直径为25 mm、高度为15 mm的十字网格圆柱体CAD模型,按每层需粘结的面积分为2个实验组,A组粘接面积为100%,B组粘接面积为80%。通过三维打印技术各制作试件5个,并对烧结后的试件进行微观结构观察与抗压强度检测。结果烧结前后的两组植入体均无明显变形,表面细节清楚。烧结后A组孔隙率为(58.58±4.35)%,抗压强度为(84.3±12.1)MPa;B组孔隙率为(68.18±0.71)%,抗压强度为(50.9±5.1)MPa。A组孔径范围为50～150μm,B组孔径大小在100～200μm之间。2组的抗压强度和孔隙率差异均具有统计学意义(P<0.01)。2组XRD衍射峰均符合HA的特征峰,证实烧结过程未发生HA的物相结构变化。结论运用三维打印技术制备的多孔羟基磷灰石植入体,其微观组织结构和抗压强度基本满足医用植入材料的要求。

Objective The aim of this study was to evaluate the feasibility of fabricating porous hydroxyapatite (HA) implant by three-dimensional(3D) printing,and provide the theory foundation and experimental base for the porous hydroxyapatite implant by observing the microstructure and testing the compression strength of the sinters.Methods The implants were designed as cylinders of 25mm diameter and 15mm height,and were divided into two groups;group A with the bonding area of 100%and group B with the bonding area of 80%.Each group included five samples fabricated with 3D printing.The microstructure of the sintered implant was observed and its compression strength was tested.Results All the porous HA implants had no significant deformation,with clear surface detail.Group A had a porosity of(58.58±4.35)%, and a compressive strength of(84.3±12.1 )MPa.Group B had a porosity of(68.18±0.71)%and a compressive strength of(50.9±5.l)MPa.The porosity size was from 50 to 150μm in group A after sintering,while that of group B ranged from 100 to 200μm.There was statistical difference(P < 0.01) between the compressive strengths of the two groups.So did the porosities of the two groups.XRD feature showed that characteristic peaks of the diffraction peaks were up to the HA, illustrating that the phases composition of HA was not changed during the sintering process.Conclusions It is confirmed that fabrication of porous HA implants by 3D printing is feasible.The microstructure and compression strength of the porous HA implants can meet the basic requirements of medical biological implantation material.