Ultrastructural estimation of the effect of sucrose and glucose rises on early dental plaque formed on plastic films.

The influence of water, glucose and sucrose rises on early plaque formation has been studied. The amount and structure of dental deposits formed on plastic films were determined on four occasions: no rinsing, water, glucose or sucrose rinses. Five subjects with healthy gingiva developed plaque in 4 h on plastic films applied to the buccal surfaces of premolars and canines, after which period the plastic films with adhering deposits were processed for electron microscopy. Sections were prepared for examination in the light and electron microscope. Some were stained for the demonstration of carbohydrates according to the periodic acid thiocarbohydrazide osmium tetroxide technique. Furthermore, the number of cellular elements collected on the films during the four experiments was calculated and statistically compared. The results in the four groups were identical. The plastic films were covered by a surface coating of acellular material in or on which bacteria, epithelial cells and leukocytes were observed. The microorganisms were almost exclusively Gram-positive cocci. Many bacteria exhibited intracellular polysaccharides. The results indicate that the rinsing procedure does not influence early plaque formation, and that frequent mouthrinses with glucose or sucrose have no detectable effect on plaque growth at this initial stage of bacterial adherence.