An in-vitro study of the role of sucrose and interactions between oral bacteria in possible mechanisms of dental plaque formation.

The adherence of streptococci to hydroxyapatite spheroids (HAS) depended upon the strain used, the fermentable carbon source available during bacterial growth, the number of times a clinical isolate had been subcultured on laboratory media and the pre-treatment of the HAS. Sucrose greatly stimulated the secondary colonization of Streptococcus mutans strain 3209 on HAS pre-equilibrated with this strain, but no similar effect was observed with glucose. Pre-equilibration of HAS with Streptococcus sanguis 7865 inhibited rather than enhanced subsequent colonization by Strep. mutans strain 3209 in the presence of sucrose.