Chapter 18 - Carbon nanomaterials for implant dentistry and bone tissue engineering

Abstract

One-dimensional carbon nanomaterials, such as carbon nanotubes (CNTs) and carbon nanofibers (CNFs), have been thought to be able to provide a favorable extracellular environment for cell adhesion due to their similar dimensions to natural collagen fibers. Studies have shown that CNTs and CNFs can selectively promote adhesion of bone-related cells (e.g., osteoblasts and mesenchymal stem cells), while reducing cell adhesion of fibroblasts and chondrocytes. However, carbon nanomaterials are inherently bioinert, only having osteoconductivity but no osteoinductivity. An effective way to improve their biological properties is to combine CNTs/CNFs with bioactive compounds like calcium phosphate (CaP) and bioactive glass (BG) compounds. Techniques including biomineralization and sol–gel/electrospinning are very useful in fabricating CNTs/CNFs with improved biological properties. Surface-functionalized CNTs and newly developed CaP (or BG) nanoparticle (NP)-decorated CNFs provide new opportunities in controlling cell growth and differentiation. Especially for CaP (or BG) NP-decorated CNFs, which are prepared by sintering electrospun polyacrylonitrile (PAN) nanofibers with sol–gel precursors containing calcium nitrate tetrahydrate, triethyl phosphate and/or tetraethyl orthosilicate precursors, show good biocompatibility, tunable degradation ability and controllable osteocompatibility, and are more favorable than pure CNFs to be applied as scaffolds for bone tissue engineering. This chapter also discusses the applications of CNT coatings on titanium implant surfaces and their potential applications in implant dentistry.