Dental caries is an infectious pathological process, manifested after teething, in which demineralization and  softening of hard tooth tissues with the subsequent formation of a defect in the form of a cavity.

   Early diagnosis of hard tissues alterations, due to carious disease, is of capital importance, in order to optimize the delay of institution of adequate preventive measures. This notion is the basis of the preventive  medical model which is based on prevention at all disease stages.

    In fact, initial lesions, which correspond to the first stages of enamel carie, are often undetected during clinical  inspection (Triller 1993), when their diagnosis at this stage allows initiation of a non invasive therapeutic measure leading to a reversible lesion.

    In this context, development of new diagnostic methods to be indispensable in order to help dentists face the requirements of modern dentistry based on prevention.