Biggemann Jonas, Hoffmann Patrizia, Hristov Ivaylo, Simon Swantje, Müller Philipp, Fey Tobias
Department of Materials Science (Glass and Ceramics), University of Erlangen-Nuernberg, Martensstr. 5, D-91058 Erlangen, Germany.
Frontier Research Institute for Materials Science, Nagoya Institute of Technology, Gokiso-cho, Showa-ku, Nagoya 466-8555, Japan.
Materials (Basel). 2020 Apr 17;13(8):1907. doi: 10.3390/ma13081907.
The manufacturing of ideal implants requires fabrication processes enabling an adjustment of the shape, porosity and pore sizes to the patient-specific defect. To meet these criteria novel porous hydroxyapatite (HAp) implants were manufactured by combining ceramic injection molding (CIM) with sacrificial templating. Varied amounts (Φ = 0-40 Vol%) of spherical pore formers with a size of 20 µm were added to a HAp-feedstock to generate well-defined porosities of 11.2-45.2 Vol% after thermal debinding and sintering. At pore former contents Φ ≥ 30 Vol% interconnected pore networks were formed. The investigated Young's modulus and flexural strength decreased with increasing pore former content from 97.3 to 29.1 GPa and 69.0 to 13.0 MPa, agreeing well with a fitted power-law approach. Additionally, interpenetrating HAp/polymer composites were manufactured by infiltrating and afterwards curing of an urethane dimethacrylate-based (UDMA) monomer solution into the porous HAp ceramic preforms. The obtained stiffness (32-46 GPa) and Vickers hardness (1.2-2.1 GPa) of the HAp/UDMA composites were comparable to natural dentin, enamel and other polymer infiltrated ceramic network (PICN) materials. The combination of CIM and sacrificial templating facilitates a near-net shape manufacturing of complex shaped bone and dental implants, whose properties can be directly tailored by the amount, shape and size of the pore formers.
理想植入物的制造需要能够根据患者特定缺损调整形状、孔隙率和孔径的制造工艺。为满足这些标准，通过将陶瓷注射成型（CIM）与牺牲模板法相结合，制造出了新型多孔羟基磷灰石（HAp）植入物。将不同量（Φ = 0 - 40体积%）尺寸为20 µm的球形成孔剂添加到HAp原料中，经热脱脂和烧结后可产生11.2 - 45.2体积%的明确孔隙率。当成孔剂含量Φ≥30体积%时，形成了相互连通的孔隙网络。研究发现，随着成孔剂含量增加，杨氏模量和抗弯强度从97.3 GPa降至29.1 GPa，从69.0 MPa降至13.0 MPa，与拟合的幂律方法吻合良好。此外，通过将基于聚氨酯二甲基丙烯酸酯（UDMA）的单体溶液渗入多孔HAp陶瓷预制件并随后固化，制造出了互穿HAp/聚合物复合材料。所获得的HAp/UDMA复合材料的刚度（32 - 46 GPa）和维氏硬度（1.2 - 2.1 GPa）与天然牙本质、牙釉质及其他聚合物渗入陶瓷网络（PICN）材料相当。CIM与牺牲模板法的结合有助于复杂形状的骨和牙科植入物的近净形制造，其性能可通过成孔剂的量、形状和尺寸直接定制。
