White spot lesions are early signs of demineralization under intact enamel, which may or may not lead to the development of caries. The reason for white spot is that the pathogenic bacteria have breached the enamel layer, and organic acids produced by the bacteria have leached out a certain amount of calcium and phosphate ions that fails to replace naturally by the remineralisation process. This loss of mineralized layer creates porosities that change the refractive index of usually translucent enamel.

White spots may also be seen after removal of orthodontic bands and brackets.  Adjunct causes of white spot lesion may include heavy plaque accumulation, inadequate oral home care routines and a high sugar or acid content diet.
 

The first line of treatment of white spot is remineralisation. There are creams, pastes and topical remineralisation treatments such as fluoride therapy, casein-phosphopeptide-amorphous calcium phosphate pastes, Novamin (calcium sodium phosphosilicate), invasive approaches such as microabrasion, conventional bonding and various types of veneers

A new minimally invasive technique for treating white spot lesions is by caries infiltration, a product of "DMG," called "Icon."

This icon prevents further progression of initial enamel caries lesions and occludes the microporosities within the lesion by infiltration with low-viscosity light-curing resins that can rapidly penetrate into the porous enamel. The resin completely fills the pores within the tooth, replacing the lost tooth structure and stopping caries progression. After conditioning of lesions using 15% hydrochloric acid gel, dessicating the tooth with ethanol is performed, which allows easy penetration of resin into the porous tooth.The resin penetrates into the lesion by capillary forces and creates a diffusion barrier inside the lesion and not on the lesion surface.
The advantage of resin infiltration is that enamel lesions lose their whitish appearance when their microporosities are filled with the resin and look similar to sound enamel.