We are interested in inhibiting the early stages of biofilm development on enamel. Using hydroxyapatite beads in solution, we measure the binding of Streptoccocus mutans in the presence of various natural products, such as green tea or cranberry extract, as well as commercial products. Our primary focus is on electrostatic contributions to the adherence step. Electrophoretic mobilities are measured by phase analysis light scattering, and the results used to calculate zeta potentials for the beads, the bacteria and the bead-bacteria complexes. More mature biofilms are also produced and visualized by fluorescence microscopy.