Detection Of Caries-associated Pathogens Based On Fluorescence Quantitative PCR And Construction Of Risk Assessment Model

Objective:The absolute amounts of potential pathogenic bacteria such as Streptococcus mutans,Prevotella,and Lactobacillus were detected to study the correlation between these pathogens and dental caries status by the approach of real-time quantitative PCR.Based on the analysis of the correlation,a model of risk assessment employed to illness screening and individual oral health tracking was constructed.Thus,it can not only guide the establishment of different periods of risk prediction model for caries,but also provid a fundamentall basis for individualized prevention,treatment and risk assessment of caries.Methods:The first step was to develop the testing process(from the activation of the strain to the construction of the plasmid);Next,saliva samples of rickets and healthy students from 251 Qingdao primary school students and 103 Guangzhou primary school students were collected for construction of rhe risk assessment model.The experiments of genomic DNA extractrction and real-time fluorescence quantitative PCR were performed;Eventually,the statistical analysis of all data was performed using the R(Version 2.15.0)software package.Results:Based on the assay of real-time fluorescence quantitative PCR,we found that:(1)the difference of Bac,Sm,Pd,and Sm_bac in health and sorghum were statistically significant(p<0.05);(2)Sm,Pp,ITS,Sm_bac were significantly different between Qingdao and Guangzhou(p<0.001);(3)there was no significant difference between the different strains in different genders p>0.05;(4)Pp,Pp_bac,ITS,ITS_bac,Sm_bac are weakly correlated with age;(5)the correlation between Sm and dmft is very strong;(6)the mixed analysis model of Sm and Pp can diagnose health and caries with high accuracy.Conclusions:(1)Sm abundance,relative abundance of Sm and Pd abundance are significantly much highe in children’s saliva from the high caries group than those from healthy children.(2)There is a geographical difference in the distribution of oral bacterial species and these varies are changed with age.(3).Based on Sm and Pp,a model with an accuracy rate of more than 70% can be constructed to help assess and screen early childhood caries risk.Both may provide new ideas for the etiology of rickets.