Study On The Relationship Between Salivary Mutans Streptococci,Lactobacillus And Deciduous Caries

Objective:1.Examine2-4years old children the concentration of salivary streptococcus mutans and lactobacillus, analysis the relationship between them and caries degree;2. Through the examining the concentration changes of Streptococcus mutans and Lactobacillus after using0.2%sodium fluoride mouthwash,analysis the mouthrinses on two kinds of cariogenic bacteria action;Methods:Through the random sampling method to examine the caries degree of275students between2to4years old, using monoclonal antibody to measure the concentration of salivary Streptococcus mutans and through the plate count method respectively measure the concentration of streptococcus mutans and lactobacillus.Giving the children0.2%sodium fluoride mouthwash to gargle one time every week, one month later collect the saliva specimens and use plate counting method to check the concentration change of Streptococcus mutans and lactobacilllus.Collect all the data into computer, using spss19.0statistical software packages to analysis the data, using the paired t test to compare average number of two samples, using one-way ANOVA to compare average number of plurality samples. using The chi-square test to compare the rate of sample. Inspection standard for bilateral alpha=0.05.Result:1.The concentration of mutans streptococci in none-caries team was2.93×10^5个/ml, in the low-caries team was6.50×10^5个/ml, in the high-caries team was12.29×10^5个/ml. With the development of the dmft, the concentration of streptococcus mutans increased significantly.2. From the plate count for bacterial colonies, the concentration of streptococcus mutans increased significantly with the increase of dmft. The detection rate of streptococcus mutans was100%while lactobacillus closed to60.0%, the detection rate of lactobacillus increased with the increased degree of caries. The caries degree of double bacteria was higher than separate streptococcus mutans group and the difference between them was statistically significant.3. After using0.2%sodium fluoride mouthwash a month, the concentrations among each group of salivary streptococcus mutans and lactobacillus decreased significantly.Conclusion:1. The average concentration of streptococcus mutans was positively related to deciduous teeth caries level. 2. The concentration of lactobacillus in dmft=0,1,2group had no obvious difference, but from dmft=3concentrations were significantly elevated, suggestive lactobacillus had a synergistic effect on caries development.3.0.2%sodium fluoride mouthwash had significant inhibitory action on salivary Streptococcus mutans and Lactobacillus...