The Relationship Of Caries Activity Of Young Children And The Cariogenic Bacteria In Saliva

Part One Analysis of caries activity in young children and its influence factorsObjective:The aim of this study was to detect the caries activity(CA)of young children and its relative influence factors to provide scientific evidence for the prevention and blocking of early childhood caries(ECC).Methods:The caries activity of children under 71 months old randomly selected were detected by Cariostat and the relative influence factors were investigated by questionnaire;meanwhile their decayed-missing-filled tooth(dmft)were examined and recorded.Results:1. There were 123 children enrolled in this study with an average age of50.2±9.6 months,and there were 66,23 and 34 children with high CA,medium CA and low CA,respectively.There were no significant difference of CA among children with different genders and ages(?~2=0.80,?~2=1.39,P>0.05);There was no significant difference of CA with different age groups(?~2=3.18,P>0.05);2.There was a positive correlation between the value of CA and their dmft(r=0.32,P<0.05).There were significant differences in caries prevalence rates and dmft among high CA group,medium CA group,and low CA group(?~2=10.23,P<0.01;?~2=15.69,P<0.01),respectively;3.There was significant difference of CA among caries-free group,ECC group and SECC group(?~2=20.31,P<0.01);4.Artificial delivery and the duration of tooth brushing less than 1minute were the susceptible factors for the young children with high CA(P<0.05);5.Higher frequency of night feeding and lower frequency of eating fruit were the susceptible factors of ECC(P<0.05).Conclusions:1.There was a positive correlation between CA and dmft in the young children.2. Artificial delivery and the duration of tooth brushing less than 1 minute were the main risk factors for high CA in children.3. Higher frequency of night feeding and lower frequency of eating fruit every day were the susceptible factors of ECC.Part Two Quantitative analysis of cariogenic bacteria in saliva of young children with different caries activityObjective:The aim of this study was to detect and compare four kinds of cariogenic bacteria in saliva including Streptococcus mutans,Streptococcus sobrinus,Lactobacillus acidophius and Actinomycetes naeslundii of young children with different caries activity to provide evidence for ECC prediction and blocking.Methods:The four kinds of cariogenic bacteria in salive of 123 children including:Streptococcus mutans,Streptococcus sobrinus,Lactobacillus acidophius and Actinomycetes naeslundii were detected by Quantitative real-time Polymerase chain reaction(real-time PCR).Result:1.The amount of Streptococcus mutans in saliva of young children with high CA,medium CA and low CA were 3.63±1.02,2.12±0.99,1±0,respectively;the difference was statistically significant(?~2=13.92,P<0.05);2.The amount of Streptococcus sobrinus in saliva of young children with high CA,medium CA and low CA were 3.29±0.35,2.04±0.90,1±0,respectively;the difference was statistically significant(?~2=6.57,P<0.05);3. The amount of Lactobacillus acidophius and Actinomycetes naeslundii in saliva had no significant difference among high CA,medium CA and low4. The amount of Streptococcus mutans in saliva of caries-free group,ECC group and SECC group were 1±0,3.51±2.23,3.96±1.64,respectively;the difference was statistically significant(?~2=6.74,P<0.05);5. The amount of Streptococcus sobrinus in saliva of children with caries-free,ECC and SECC group were 1±0,2.86±0.59,3.52±1.18,respectively;the difference was statistically significant(?~2=8.01,P<0.05);6. The amount of Actinomycetes naeslundii in saliva of caries-free group,ECC group and SECC group were 1±0,3.39±0.37,3.66±0.82,respectively;the difference was statistically significant(?~2=7.72,P<0.05);7. There was no significant difference in the amount of Lactobacillus acidophius in saliva among children with caries-free,ECC and SECC group(?~2=2.43,P<0.05).Conclusions:1.Streptococcus mutans and Streptococcus sobrinus in saliva of early children were closely related with the caries activity of young children.2.Streptococcus mutans,Streptococcus sobrinus and Actinomycetes naeslundii in saliva of young children were closely related to the incidence of ECC.