In the past dental caries was thought to be a constant and continuous process, currently it is viewed as episodic in  progression. 

The surface of enamel is dynamic and in a constant state of flux depending on the microbial and chemical consistency of saliva and plaque.   
 

Changes in these environments (saliva and plaque) can either have a detrimental or beneficial affect on the enamel surface.  The detrimental affect can be identified as the early, reversible event in dental caries, the white spot lesion.  
 

The early observation and clinical evaluation of white spot lesions on the tooth surface provide the dentist with important information about the state or the disease process (active or inactive).