Hard tissues play indispensable roles in the support, mastication and protection of the internal organs in the human being. To date, hard tissue-related diseases and defects have been developed into a type of common cases in the clinic. Over the past few decades, the use of autogenous and allogenous tissue grafts has been the traditional method to repair hard tissues. However, the harvest of bone grafts inevitably
Jianrong Wei, Tianxiao Zhao and Jie Liao contributed equally to this work.
J. Wei • T. Zhao • J. Liao • Y. Liu • L. Li • X. Li (*)
© Springer Nature Singapore Pte Ltd. 2017
X. Li (ed.), Tissue Repair, DOI 10.1007/978-981-10-3554-8_7
leads to the increase of additional trauma parts, and the available tissue source is not enough in many cases. Recently, using biomaterials to repair hard tissue have been widely studied due to their special properties which can overcome or avoid the deficiencies of bone grafts [1, 2].
Currently, traditional hard tissue repair materials are metals, polymers, ceramic materials and their composites [3, 4]. The metal replacement materials are one kind of the most frequently used substitutes in orthopedic and dental fields, such as artificial joint, artificial centrum, fracture fixation plate, bone nails, dental implants [5, 6]. Polymers, including polyester, polyethylene, polytetrafluoroethylene, polylactic acid, etc., have been used as another kind of artificial bone and joint materials [7, 8]. Moreover, biological ceramics play an important role in the repair and reconstruction of the hard tissues . However, the current hard tissue repair materials cannot satisfy all the clinical requirements. Therefore, numerous novel biomaterials have been tried to be applied in hard tissue repair, one of which is the scaffolds reinforced by fibers or tubes . After the study of past 20 years, this kind of reinforced scaffolds have very wide application range, not only concerning small hard tissue defect repair but also having the ability to repair big ones based on their excellent mechanical properties.
To achieve the satisfactory-performaced scaffolds, their physical and mechanical properties, such as porosity, pore interconnectivity, pore size, mechanical strength and the surface-area-to-volume ratio(SA:V) should be comprehensively studied
 . It has been shown that those properties also have significant effects on the biocompatibility and biodegradability of the scaffold, thereby indirectly influencing the promotion of cellular functions in the scaffold within the surrounding tissues
 . The availability of nutrients and oxygen required for cell viability and infiltration are strongly dependent on the scaffold’s porosity, pore interconnectivity and pore size [13-15]. Sufficient mechanical strength is required for the scaffold to support itself against the surrounding tissues during cell proliferation. Also, it has been shown that the attachment and proliferation of cells can be readily improved by increasing the scaffold SA:V [16-19]. Recently, fibers or tubes based structures applied in hard tissue repair attract much attention by providing large functional surfaces for desired biological interactions and cell adhesion [20-22]. Moreover, the mechanical properties of tissue engineering scaffolds reinforced by fibers or tubes can be well controlled to meet the requirements of different hard tissue repair.
In this chapter, we mainly introduce the special properties and their influential factors of scaffolds reinforced by fibers or tubes for hard tissue repair, mainly focusing on their special design and fabrication and how the addition of fibers or tubes affects the special functions in vitro and in vivo. In addition, the recent studies to improve the mechanical properties of the scaffolds reinforced by fibers or tubes will be discussed. Moreover, the current applications of this kind of reinforced scaffolds in hard tissue repair are reviewed from two aspects: dental repair and bone repair. Each aspect will be detailedly introduced from in vitro and in vivo studies, which indicates that the scaffolds reinforced by fibers or tubes have great potential to be more widely used for hard tissue repair in near future.