Glycolysis in Films of Oral Samples from Persons with Different Caries Rates

¹ Departments of Dental Science and Oral Pediatrics, Tufts University School of Dental Medicine, Boston, Massachusetts

A study was performed on rates of glycolysis in thin films of oral samples obtained from children selected for high or low susceptibility to dental caries. Samples of dental plaque were collected by instrumentation, and salivary sediment was obtained both by brushing or by mastication. The samples were prepared in the form of thin films and placed in contact with glass electrodes. The pH obtained with and without added substrate was determined at a steady state, and the pH curves for brief treatments with sugar were followed for 2-4 hours. The general goals were to obtain knowledge regarding the relative influence of different factors on the pH of films and to discover what parameter of glycolysis rates might have been correlated with caries rates.

There was great similarity between sediment obtained by chewing of paraffin and that obtained by toothbrushing. Dental plaque generally gave values of pH which fell from eight-tenths of a unit to one unit below those obtained for salivary sediment, but good correlation appeared to exist between the behaviors of these 2 materials.

No indication was obtained for the presence of a glycolysis-stimulating or -inhibiting factor in the supernatant liquid from either the caries-resistant or the caries-susceptible groups. Comparisons were made between 3- and 15-minute treatments with strong and weak solutions of glucose and sucrose. The stronger solution and longer contact increased the magnitude of the pH drop and the duration of the pH depression. There was some evidence of greater pH depression with sucrose. None of the measures of glycolysis rates appeared to be diagnostic of the dental caries attack rate of the subject.