This in vitro study performed elemental analysis of the ions absorbed into the salivary coat covering the surfaces of S-PRG resin blocks and assessed the adherence of Streptococcus sanguinis and Streptococcus mutans to these saliva-coated S-PRG resin blocks. Elemental analysis of ions absorbed into the salivary coat of resin blocks exposed to the saliva was performed using an inductive coupled plasma atomic emission spectrometer and the fluoride electrode method. Quantitative adherence of radio-labeled test bacteria to the resin blocks was determined. As the results, the saliva-coated S-PRG resin showed significantly greater amounts of absorbed B, Al, Si, Sr, and F than the saliva-coated unfilled resin. It was of particular significance that the salivary coating of the S-PRG resin reduced the adherence of S. mutans to this resin. However, in the case of S. sanguinis, no significant difference in adherence could be recognized between saliva-coated S-PRG resin and saliva-coated unfilled resin.