<prompt> Critical pH for initiation of caries in dentin is:4.3-4.55.2-5.54.9-5.16.2-6.5  <response>: Critical pH for initiation of caries in dentin is 6.2-6.5.In addition, the critical pH for dentin is higher than for enamel, so demineralization is likely to start even before the pH reaches the critical level for enamel pH 5.5. 