Caries is a biofilm [plaque] induced acid demineralization of enamel or dentin, mediated by saliva.  Although cavitated lesions have a bigger impact on children’s quality of life, diagnosing and treating white spot lesions is very important for implementing early intervention strategies and overcoming the aggressive course of early childhood caries.

Carbonic anhydrase VI [CA VI] is the primary salivary zinc metalloprotein responsible for regulation of buffer capacity and salivary pH  homeostasis by catalyzing the hydration reaction. This enzymatic ability facilitates acid neutralization and maintenance of pH in the oral cavity. Fluoride release can prevent demineralization and promote the remineralization of early WSLs.

In spite of the current understanding regarding the role of CA VI in saliva and occurrence of caries, at least to our knowledge, no study has investigated salivary CA VI concentration and activity of children with white spot lesions before and after application of fluoride varnish. So, the aim of the present study is to determine quantitatively salivary CA VI for caries susceptibility in white spot lesions in preschool children.