Department of Materials Science and Engineering, University of Sheffield, Sir Robert Hadfield Building, Mappin St, Sheffield S1 3JD, UK; Kroto Research Institute, University of Sheffield, Broad Lane, Sheffield S3 7HQ, UK; Insigneo Institute for in silico Medicine, University of Sheffield, Pam Liversidge Building, Mappin St, Sheffield S1 3JD, UK; Department of Prosthodontic, College of Dentistry, University of Kufa, Najaf, Iraq.
Medical Advanced Manufacturing Research Centre (AMRC), Wallis Way, Catcliffe, Rotherham S60 5TZ, UK.
J Mech Behav Biomed Mater. 2019 Feb;90:20-29. doi: 10.1016/j.jmbbm.2018.08.047. Epub 2018 Aug 29.
Dental implants need to support good osseointegration into the surrounding bone for full functionality. Interconnected porous structures have a lower stiffness and larger surface area compared with bulk structures, and therefore are likely to enable better bone-implant fixation. In addition, grading of the porosity may enable large pores for ingrowth on the periphery of an implant and a denser core to maintain mechanical properties. However, given the small diameter of dental implants it is very challenging to achieve gradations in porosity. This paper investigates the use of Selective Laser Melting (SLM) to produce a range of titanium structures with regular and graded porosity using various CAD models. This includes a novel 'Spider Web' design and lattices built on a diamond unit cell. Well-formed interconnecting porous structures were successfully developed in a one-step process. Mechanical testing indicated that the compression stiffness of the samples was within the range for cancellous bone tissue. Characterization by scanning electron microscopy (SEM) and X-ray micro-computed tomography (μCT) indicated the designed porosities were well-replicated. The structures supported bone cell growth and deposition of bone extracellular matrix.
种植牙需要与周围骨骼实现良好的骨整合，才能充分发挥功能。与整体结构相比，具有互联多孔结构的种植牙具有更低的刚度和更大的表面积，因此更有可能实现更好的骨-种植体固定。此外，对孔隙率进行分级可以使种植体外围有较大的孔用于长入，而核心更致密以保持机械性能。然而，由于种植牙的直径较小，实现孔隙率的渐变非常具有挑战性。本文研究了使用选择性激光熔化 (SLM) 技术，通过各种 CAD 模型来生产具有规则和渐变孔隙率的一系列钛结构。这包括一种新颖的“蛛网”设计和基于钻石单元的晶格。通过一步工艺成功开发了具有良好连通性的多孔结构。压缩刚度测试表明，样品的压缩刚度在松质骨组织的范围内。扫描电子显微镜 (SEM) 和 X 射线微计算机断层扫描 (μCT) 的特性表明，设计的孔隙率得到了很好的复制。这些结构支持骨细胞的生长和骨细胞外基质的沉积。
