Dental caries is a biosocial disease and its causes are rooted in the culture technology and economy of our society. Implicit in this statement is the explanation as to why caries prevention with diet control has met with only moderate success.The answer to this major public health problem must be prevention, if for no other reason than the realities of the coast of health care being forced upon us. With this perspective in mind, it is clear that the prevention of occurrence of the disease as well as the limitation of the damage caused by it can only be truly achieved by judging the susceptibility of the individual to caries attack and detecting the lesion in a stage where the natural defenses of the body can heal the lesion. Thus the precavitation stages of the lesion should be detected with the help of non-invasive techniques.Knowledgeable clinical judgment based on the patient’s case history, visual cues, review of radiographs and probability of disease is a necessity for the provision of optimum care. New technologies may provide supplemental information, but they cannot yet replace established methods for the diagnosis of caries.