1.Measurement of exopolysaccharides produced by Streptococcus mutans from caries-free and caries-active children
Qinghui ZHI ; Huancai LIN ; Yidong LIAO
Journal of Practical Stomatology 1995;0(04):-
Objective: To compare the quantities of water-soluble, water-insoluble glucans synthesized by S. mutans in 3-4 years old children with high dmft and no caries. Methods: The quantities of water-soluble and water-insoluble glucans synthesized by S. mutans from dental plaques of children with high dmft (dmft≥5) and caries-free (dmft=0) were measured using the anthrone method. Results: S. mutans isolated from the children with high dmft had stronger ability in producing both water-soluble and water-insoluble glucans than those isolated from the caries-free children (0.0332 mg/ml v.s. 0.0192 mg/ml and 0.0357 mg/ml v.s. 0.0215 mg/ml respectively). Children with high dmft harbored more isolates with higher water-soluble or water-insoluble glucans producing ability than caries-free children. Water-insoluble glucans produced by all the clinical isolates is higher than water-soluble glucans (0.0301 mg/ml v.s. 0.0267 mg/ml) and the difference was statistically significant. Conclusion: There may be a correlation between the extracellular glucans producing ability of S. mutans and the caries susceptibility in deciduous teeth.
2.Determination of fluoride concentrations in toothpastes by using ion chromatography
Wei HE ; Huancai LIN ; Qinghui ZHI
Journal of Practical Stomatology 2000;0(05):-
0.05) but the recovery rate of MFP2- by IC and by FSE was statistically different (1.00 v.s. 1.08; P