Figure 1.

Schematic representation of MMP activity during the dentin carious process. Cariogenic bacteria present in the caries cavity release acids such as lactic acid that reduce the local pH. The resulting acidic environment demineralizes the dentin matrix and induces the activation of host MMPs derived from dentin or saliva (which bathes the caries cavity). Once the local pH is neutralized by salivary buffer systems, activated MMPs degrade the demineralized dentin matrix.