Effect of sucrose intake on numbers of bacteria in plaque expressing extracellular carbohydrate metabolizing enzymes

The effect of sucrose intake versus a sucrose-free diet (substituting glucose for sucrose) on numbers of isolates from early dental plaque expressing extracellular carbohydrate metabolizing enzymes was studied. The bacteria were isolated from 0- to 3-day-old dental plaque formed on the buccal surface of a lower premolar in 6 subjects. A total of 7,987 isolates were tested for the following activities: synthesis of glucan from sucrose, glucanase, fructanase, synthesis of polymers from glucose, and amylase. Sucrose intake was associated with relatively low numbers of isolates expressing the enzyme activities studied at the start of plaque formation and relatively high numbers in 2- and 3-day plaque. The enzyme activities studied are important elements in the pathophysiology of dental caries and may even be addressed as virulence factors.