Adhesion of S. parasanguinis to saliva-coated hydroxylapatite. Wild type of S. parasanguinis FW213, Gap3 site-directed mutants (L64R, P65R, I66N and L67T), fap1 mutant VT1393, gap3 mutant VT1619 and gap3 complemented strain gap3-/gap3+ were labeled with [3H] thymidine respectively. Labeled cells were incubated with SHA. The amounts of radioactivity associated with beads and supernatants were determined in a Wallac 1400 liquid scintillation counter and calculated to determine adhesion percentage. The data were obtained from three independent experiments in three replicates and are presented as means ± standard deviation.