White Spot Carious Lesions 3:

1. Scanning electron microscopy of white spot enamel lesions at all stages show direct dissolution with enlargement of intercrystalline spaces (1).  The diffusion of minerals into and out of the enamel is determined by these porosities and are important in both the pathological and healing process.

2.The disappearance of white spots can be by remineralization and/or surface abrasion (2) .

3. In select cases where esthetics is not a problem, it is possible to monitor lesions with frank cavitation without placing a restoration if there is evidence that plaque free conditions are maintained and the disease process has been arrested (3).

4. Clinical importance of the repair process:
     -Demonstrated by in vivo studies (1).
     -Low fluoride levels enhances rate and degree of remineralization (3).
     -Remineralized enamel is more resistance to caries attack (more acid insoluble) than intact enamel (4).
     -Repaired enamel has greater organic content which helps resist acid attack (4).
     -In a human study 71 white spot lesions were tracked for 7 years with the following results:
        -9 lesions progressed to caries.
        -25 lesions remained unchanged.
        -37 lesions where no longer detectable (5).

5. The white spot lesion is not considered as a distinct form of dental caries but a stage of the carious process.
      -This lesion can be active progressing to cavitation, it may be inactive not progressing or may even be healing.
      -Active lesions have  a porous surface which clinically appears chalky and with the explorer feels rough.  Under proper conditions these areas can remineralize and converted into arrested or nonactive lesions..
      -Nonactive lesions have a relatively non-porous  surface that is smooth, shinny and hard (2).

1.   Holeman,L et al. A SEM study of progressive stages of enamel caries in vivo. Caries Res. 19:355-367, 1985.
2.    Zero DT, Application of clinical models in remineralization research. J Clinical Dent, 10:74-85, 1999.
3.    Nuyvad B, Fejerskov O: Assessing the stages of caries lesion activity on basis of clinical and micobiological examination. Communty Den Oral Epidemiol 25:60-75,1997.
4.    Silverstone LM. Remineralization phenomena. Caries Res 11:59-84,1988.
5.    Backer Dirks, JDR 45:503, 1966