Simulation of natural enamel caries in vitro with methylcellulose acid gels: effect of addition of calcium and phosphate ions.

A modified acid gel technique for producing caries-like lesions in dental enamel has been developed. The decalcifying medium consists of a 10% (w/v) methylcellulose gel acidified with 0.1 M lactic acid-sodium lactate at pH 4.5 and having a hydroxyapatite content of 0.05% (w/v). This medium can produce caries-like lesions in vitro at a slow rate, which are indistinguishable from natural enamel caries when examined by polarised light microscopy and contact microradiography.