Figure 1. Mineral density (log Ca:P) of the restored root surface after 3 weeks’ culture with oral biofilm. The log Ca:P was measured by energy-dispersive spectroscopy from the root surface to 200 µm in depth (total of 10 x 3 x 5 = 150 spot analyses for each restorative material tested and 150 internal controls for each group, giving 300 analyses). Glass-ionomer cement was the only material to show an increase in log Ca:P at the root surface adjacent to the restoration (P < 0.01). The log Ca:P tailed off at distances farther from the interface. Such results were not found at the enamel surface.