Figure 5. Plots of the steady-state Ca concentration ([Ca]_s), which was determined analytically after 30 hrs of equilibration in systems with various fluoride concentrations ([F]_ex). The [Ca]_s decreased almost linearly when [F]_ex was increased in both systems with and without protein coatings of the seed crystals. In both systems, increasing the fluoride concentration resulted in the retention of [Ca]_s at lower levels. The data with deviation bars were obtained from triplicate experiments, while the data without the bars were obtained from duplicate experiments. Note that enamel proteins substantially modified the [Ca]_s, by reducing the Ca consumption for precipitation.