The Study Of S.m In Dental Plaque Between Severe Chronic Periodontitis And High Dental Caries

Objective:1. To investigate and analysis whether there exist any differences between Severe Chronic Periodontitis and High Dental Caries with the index of CPI and DMFT. To approach the relation between Caries and Periodontitis.2. To study the CFU and genetype of streptococcus mutans(S.m) from dental plaque of patients with Severe Chronic Periodontitis without Dental Caries, High Dental Caries without Periodontitis and no dental disease. To approach whether there exist any differences between them, and to explore the relationship between them. To acquire a deep understanding of the etiological relation between Caries and Periodontitis. Further make a experimental evidence for whether there exist interaction between Caries and Periodontitis at the onset stage of disease.Method:1. To analysis the data from march to july of 2009 with 25-65y of Severe Chronic periodontitis and High Dental Caries from Dental Hospital of Henan Provice with Wilcoxon rank-sum test atα=0.05.2.29 samples up to standard with 25-59y were gotten from Dental Hospital of HeNan provice which contained 10 samples of Severe Chronic Periodontitis without dental caries,7 samples of High Dental Caries without Periodontitis and 12 samples of health group. Supragingival plaques of the first molar of submaxilla from every sample were taken. After concussion, deliquation, anaerobic cultivation for 48h, identification, then DNA extraction, PCR, counting and AP-PCR, then the CFU and Genetype of S.m were taken. Handle these data with Pearson Chi-Square at a=0.05.Result:1. We got 111 samples of Severe Chronic periodontitis including male 80 female 31 and 57 high dental caries including male 14 female 43, which are from Dental Hospital of HeNan provice. The statistics result of average age with disease between Severe Chronic periodontitis group and high dental caries group has significant differences(t=-3.389,p=.001,t-test), so we consider that the average age with disease of high dental caries group is younger than that of Severe Chronic periodontitis group. The statistics result of proportion of male and female between Severe Chronic periodontitis group and high dental caries group has significant differences (x2=34.493, p=.000, Pearson chi-square), so we consider that the proportion of male of Severe Chronic periodontitis group is larger than that of high dental caries group and the proportion of female of high dental caries group is larger than that of Severe Chronic periodontitis group. The index of CPI between two group have got significant differences (z=-9.777, p=.000, Wilcoxon rank sum test), so we consider that CPI of high dental caries group was lower than that of Severe Chronic periodontitis group. The index of DMFT between two group have got significant differences (z=-9.837, p=.000, Wilcoxon rank sum test), so we consider that DMFT of high dental caries group was higher than that of Severe Chronic periodontitis group.2. The number of S.m of every group have got significant differences (F=6.685, p=.005, one-way AN OVA), we consider that there exist differences among the group. The number have got significant differences (p=0.02, LSD-t) between High Dental Caries without Periodontitis and Severe Chronic periodontitis without Dental Caries; The number have got significant differences (p=0.04, LSD-t) between High Dental Caries without Periodontitis and health group; The number have no difference (p=0.689, LSD-t) between health group and Severe Chronic periodontitis without Dental Caries.3. We isolated 260 stains which included 94 stains of Severe Chronic periodontitis without Dental Caries and 63 stains of High Dental Caries without Periodontitis and 103 stains of health group. We got 42 genetypes from DNA of 260 isolated stains, which inclued 11 genetypes of Severe Chronic periodontitis without Dental Caries and 18 genetypes of High Dental Caries without Periodontitis and 13 genetypes of health group. The polymorphism constituent ratio of genetype were 11.7%,28.6%,12.6%.4. The constituent ratio of genetype of three group have got significant differences (x2=9.497, p=.009, pearson chi-square). The constituent ratio of genetype have got significant differences (x2=7.128, p=0.008, Pearson chi-square)between High Dental Caries without Periodontitis and Severe Chronic periodontitis without Dental Caries; The constituent ratio of genetype have got significant differences (x2=6.548, p=0.01, Pearson chi-square) between High Dental Caries without Periodontitis and health group; The Genetype have no significant differences (x2=0.039, p=0.844, Pearson chi-square) between health group and Severe Chronic periodontitis without Dental Caries.Conclusion:1. The results suggest that there exist antagonistic relationship between etiological factors of the severe chronic periodontitis and high dental caries. The relationship of the two pathogenic bacteria is worthy of further research.2. The lgCFU results suggest that S.m as a major factor to lead to caries. Its number and activity closly related. There exist agonistic relationship between cariogenic bacteria and periodongtopathic bacteria.3. The results suggest that genetype of S.m has extensive polymorphism. The number of genetypes and activity of leading to caries closly related. The leading status of periodongtopathic bacteria may suppress the CFU, activity and the genetype polymorphism of S.m, and vice verse.