Tooth loss due to several reasons affects most people adversely at some time in their lives. A biological tooth substitute, which could not only replace lost teeth but also restore their function, could be achieved by tissue engineering. Scaffolds required for this purpose, can be produced by the use of various techniques. Cells, which are to be seeded onto these scaffolds, can range from differentiated ones to stem cells both of dental and non-dental origin. This chapter deals with overcoming the drawbacks of the currently available tooth replacement techniques by tissue engineering, the success achieved in it at this stage and suggestion on the focus for future research.
Tissue Engineering Approach
Tissue engineering (TE) is a multidisciplinary area that integrates the principles of engineering and biological sciences to develop a biological substitute, which can be used to repair, regenerate or replace parts of the body.
A general approach of TE involves the use of temporary porous three-dimensional scaffolds to: (a) define the complex anatomical shape of the tissue, (b) guide the proliferation and differentiation of seeded cells and (c) provide mechanical support for the cells (Morsi et al). Thus scaffold plays a key role in tissue engineering by providing the initial extracellular matrix required to support the growth and proliferation of cells.
Various techniques are available for manufacturing the three-dimensional scaffolds that are dependent on the optimal scaffold required for the application on hand. The ideal scaffold should posses following characteristics: (i) the rate of scaffold degradation should be in accordance to the rate of tissue growth, (ii) the surface of the scaffold should be conductive to cell attachment, growth and differentiation, (iii) possess required pore size and interconnectivity for tissue integration, vascularisation and transfer of nutrients and waste removal, (iv) have adequate mechanical strength and flexibility to suit intended application, (v) possess high surface area to volume ratio and (vi) the scaffold should be easy to process and be manufactured in a cost effective manner.
The design of an ideal scaffold has to be accompanied by the selection of a suitable material. Several synthetic biodegradable polymers, such as polyglycolic acid (PGA), polylactic acid (PLA) and their copolymers, natural materials like collagen, fibrin and alginate are the most commonly used materials as scaffolds for tissue engineering applications. Irrespective of the type of material used and its application, it should be biocompatible, easy to modify, should have structural stability, and should be versatile, biodegradable and malleable.