Dental caries is a localized, destructive, and progressive infection
of dentin; if left unchecked, caries can result in pulpal
necrosis and potential tooth loss. Both bacterial byproducts
and products from the dissolution of the organic and inorganic
constituents of dentin mediate the effects of dental caries on
the pulp. Three basic reactions tend to protect the pulp against
caries: (1) a decrease in dentin permeability, (2) tertiary dentin
formation, and (3) inflammatory and immune reactions. These
responses occur concomitantly, and their robustness is highly
dependent on the aggressive nature of the advancing lesion