ABSTRACT
Light has always been the dentist’s first diagnostic tool. Visual inspection of both the teeth and gums is still the first method used by all dental practitioners around the world. A skilled dentist can distinguish between direct reflection from the tooth’s surface and light scattered back from the deeper tissue structure and evaluate if mineral is being lost through the caries process. This chapter presents, in basic terms, the way that light can interact with a range of materials covering effects such as reflection, scattering, polarization and fluorescence. These physical processes are then placed into the context of the detection, and subsequent diagnosis, of dental disease. The chapter then explores the technical advances that have been made to help use the effects of the interaction of light with oral tissue, both hard and soft, to aid the dentist. Methods covered include the use of transillumination, fluorescence imaging, near infrared imaging, depth profiling through a lesion and spectroscopic inspection. Some ideas on what features a perfect instrument might provide are discussed and where the dental imaging field may progress to in the future.
