Dental caries is easily diagnosed but there is considerable difficulty in deciding the earliest stage in the progression of a carious lesion at which diagnosis can be made without reasonable doubt. Early detection and diagnosis allow the dentist to counsel and assist patients to prevent the progression of caries and thereby avert the need of invasive, irreversible removal and restoration of tooth structure.In recent years, various techniques have been explored to address the need for better detection tools to aid dentist in the diagnosis of early caries and several of these methods have been developed into commercial product. Thus the new era of dental world has provided us with newer techniques like Digital Radiography, Diagnodent, Optical Coherence Tomography, Terahertz Imaging etc. with the advantages of more reliable, accurate, sensitive, specific and inter & intra examiner accuracy. By utilizing the most conservative, reliable diagnostic methods to detect true carious lesions, the dental professional can enhance the predictability of preventive methods to control the caries process and ultimately further reduce the need for restorative treatment.

Medicine and social sciences are concerned in their own special way with human behavior. The term 'social sciences' is applied to those disciplines which are committed to the scientific examination of human behaviour. These are economics, political science, sociology, social psychology and social anthropology. The term 'behavioural sciences' is applied to the last three, i.e., sociology, social psychology and social anthropology, because they deal directly with human behaviour.