The initial stages of the carious lesion are characterised by a partial dissolution of the tissue, leaving a 2-μm to 50-μm thick mineralised surface layer and a subsurface lesion with a mineral loss of 30% to 50% extending into enamel and dentine. In a clinical examination, the lesion will appear chalky white and softened. In practice, the goal is to stop the process at the white spot lesion stage, when intervention can still be nonsurgical.
If the lesion advances, the outer enamel layer can eventually become cavitated. At this point the lesion is not reversible and requires operative intervention. Besides observing an obvious hole in the tooth during a clinical examination, the dental professional might also notice that an advanced lesion will feel “sticky” or soft when gently touched with a dental probe.