Sucrose metabolism in situ by dental plaque in appliance-borne bovine enamel tooth fissure inserts in man

Sucrose metabolism of dental plaque which accumulated in fissure-like spaces between small bovine enamel cubes on removable U-shaped appliances was analysed using radiolabelled techniques. The appliances were worn by 8 dental students for 21 days. Half of the fissural inserts (3) on one wing of the appliance were exposed to a 10 per cent sucrose solution in normal saline and half (3) to normal saline as a control on the opposite wing, 8 x/day. At 21 days [14C]-sucrose (U) was applied directly to sucrose and saline-exposed inserts extra-orally for 60 min at 37 degrees C (non-dispersed plaques, NDP). Adjacent inserts on both sides of the appliances were removed. The plaque was dispersed in buffer by sonication, cultured and was exposed to radiolabelled sucrose for the same incubation period (dispersed plaques, DP). The following observations were made: (1) quantitative values for sucrose consumption and lactic acid, cell-bound and insoluble product, soluble polysaccharide, carbon dioxide and total volatile acid formation did not differ between sucrose and saline exposed DP or sucrose- and saline-exposed NDP; (2) all DP consumed more sucrose and formed higher quantitative levels of all products than NDP counterparts, p less than 0.001; (3) sucrose-exposed DP and sucrose exposed NDP formed proportionally more lactic acid than saline-exposed counterparts, p less than 0.05; (4) sucrose-exposed NDP formed proportionally more lactic acid and less soluble polysaccharide than sucrose exposed DP, p less than 0.025; (5) concentrations of lactobacilli were higher in sucrose exposed plaques, p less than 0.049.