Biomaterials in Relation to Dentistry.

Dental caries remains a challenge in the improvement of oral health. It is the most common and widespread biofilm-dependent oral disease, resulting in the destruction of tooth structure by the acidic attack from cariogenic bacteria. The tooth is a heavily mineralised tissue, and both enamel and dentine can undergo demineralisation due to trauma or dietary conditions. The adult population worldwide affected by dental caries is enormous and despite significant advances in caries prevention and tooth restoration, treatments continue to pose a substantial burden to healthcare. Biomaterials play a vital role in the restoration of the diseased or damaged tooth structure and, despite providing reasonable outcomes, there are some concerns with clinical performance. Amalgam, the silver grey biomaterial that has been widely used as a restorative material in dentistry, is currently in throes of being phased out, especially with the Minimata convention and treaty being signed by a number of countries (January 2013; http://mercuryconvention.org/Convention/) that aims to control the anthropogenic release of mercury in the environment, which naturally impacts the use of amalgam, where mercury is a component. Thus, the development of alternative restoratives and restoration methods that are inexpensive, can be used under different climatic conditions, withstand storage and allow easy handling, the main prerequisites of dental biomaterials, is important. The potential for using biologically engineered tissue and consequent research to replace damaged tissues has also seen a quantum leap in the last decade. Ongoing research in regenerative treatments in dentistry includes alveolar ridge augmentation, bone tissue engineering and periodontal ligament replacement, and a future aim is bioengineering of the whole tooth. Research towards developing bioengineered teeth is well underway and identification of adult stem cell sources to make this a viable treatment is advancing; however, this topic is not in the scope of this chapter. Whilst research focuses on many different aspects, operative dentistry involves the wide use of restorative biomaterials; thus, the development of smart biomaterials to suit the current climes of minimally invasive dentistry is important. The concept of minimally invasive dentistry primarily promotes preservation of the natural tissue, and, thus, the prevention of disease or the advancement of procedures that allow early detection and interception of its progress with minimal tissue loss are of significance. This chapter presents, in brief, the current state of the art of direct restorative biomaterials and their role and future in the field of dentistry. Modern dental practice is highly reliant on the selection of appropriate materials for optimum function and benefit to the patient. Dentistry, perhaps, has the unique distinction of using the widest variety of materials, ranging from polymers, metals, ceramics, inorganic salts to composite materials. So far, aesthetics of restorative materials and their ability to perform in the harsh oral environment without undergoing changes in dimension and stability has been the major focus of materials used in dentistry. Despite advances in tissue engineering and regeneration in the field of regenerative medicine, this concept has found relatively limited application for enamel and dentine due to their limited ability to remodel, but research related to biomimetic approaches for the modification of dentine is a significant step.