School of Dentistry, College of Dental Medicine, Kaohsiung Medical University, Kaohsiung, 807, Taiwan; Orthopaedic Research Center, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan; Department of Medical Research, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan.
Department of Mold and Die Engineering, National Kaohsiung University of Science and Technology, Kaohsiung, 807, Taiwan.
Mater Sci Eng C Mater Biol Appl. 2020 Mar;108:110192. doi: 10.1016/j.msec.2019.110192. Epub 2019 Nov 1.
This study provided an eco-friendly manufacturing method for Ti implants by combining machining and surface treatment processes. Ti was machined by electrical discharge machining (EDM) in a water-based dielectric in order to reduce environmental impact and improve operational health. The feasibility of this eco-friendly EDM was evaluated by tested the bioactivity and cytocompatibility of the EDM-treated Ti and the commercially micro-arc oxidation (MAO)-treated Ti was used as a control group. Pulsed MAO and EDM treatments were applied on Ti in an aqueous solution containing hydroxyapatite (HA) with the same concentration (30 g/L) under the same voltage and treatment period. The two surface modification processes were compared from the aspects of surface composition, coating structure, and coating adhesion. Furthermore, in vitro bioactivity and cellular biocompatibility of the MAO- and EDM-treated Ti films were tested. Both treatments produced Ti oxide containing Ca and P on Ti, and the EDM-formed film possessed more Ca, with its Ca/P value closer to HA, as compared to the MAO-formed film. The MAO-formed films had micropores and nanopores in the middle region and film/substrate interface, respectively. Pores only existed on the surface of the EDM-formed films. The MAO-formed films were fractured, but the EDM-formed films maintained their original structure under tensile stress, tested according to the ASTM C633 standard. The bioactivity of the EDM-treated surface was higher than that of the MAO-treated and untreated Ti surface. After 24 h cell incubation, the EDM-treated surface exhibited a significantly higher number of cells than untreated Ti and the MAO-treated surface.
本研究通过结合机械加工和表面处理工艺，为 Ti 植入物提供了一种环保的制造方法。Ti 采用水基介电中的电火花加工（EDM）进行加工，以减少环境影响并提高操作健康。通过测试 EDM 处理后的 Ti 的生物活性和细胞相容性来评估这种环保 EDM 的可行性，商用微弧氧化（MAO）处理后的 Ti 被用作对照组。在含有相同浓度（30g/L）羟基磷灰石（HA）的水溶液中，对 Ti 施加脉冲 MAO 和 EDM 处理，施加相同的电压和处理时间。从表面成分、涂层结构和涂层附着力等方面比较了两种表面改性工艺。此外，测试了 MAO 和 EDM 处理后的 Ti 薄膜的体外生物活性和细胞相容性。两种处理方法都在 Ti 上生成了含有 Ca 和 P 的 Ti 氧化物，与 MAO 形成的薄膜相比，EDM 形成的薄膜具有更多的 Ca，其 Ca/P 值更接近 HA。MAO 形成的薄膜在中间区域和薄膜/基底界面分别具有微孔和纳米孔。而 EDM 形成的薄膜表面只有孔。MAO 形成的薄膜发生了断裂，但 EDM 形成的薄膜在根据 ASTM C633 标准进行的拉伸应力测试中保持了其原始结构。EDM 处理表面的生物活性高于 MAO 处理和未处理 Ti 表面。细胞孵育 24 小时后，EDM 处理表面的细胞数量明显高于未处理 Ti 和 MAO 处理表面。
