[Impact of maternal caries risk on children's caries susceptibility]

To evaluate the impact of caries risk of pregnant mothers on caries susceptibility of infants in order to provide a basis for effective control and prevention of the occurrence and development of early childhood caries.

A total of 140 pregnant women and infants from 4 to 9 months of gestation in Xicheng and Miyun Maternal and Child Health Hospital were selected as the study subjects. According to WHO 2013 caries diagnosis standard, oral examination, questionnaire survey and stimulating saliva samples of pregnant mothers were collected. Caries activity was determined using the Dentocult SM, Dentocule LB and Dentobuff Strip standard kit. At 6 months, 1 year, and 2 years, caries was recorded and resting saliva samples were collected. Nested PCR was used to detect the colonization of S.mutans in infants at 6 months, 1 year, and 2 years of age. Statistical analysis was concluded with SPSS 21.0 software package.

After 2 years of observation, the rate of lost follow-up was 11.43%, 124 pairs of mother-child were followed up. The study was divided into moderate and low caries risk (LCR) group and high caries risk (HCR) group based on the number of open caries (untreated cavities) in mothers, detection of Streptococcus mutans by Dentocult SM, Lactobacillus by Dentocule LB, saliva buffering capacity by Dentbuff Strip, and questionnaire results. The results showed that the prevalence of white spot(18.33%) and dmft (0.3±0.087) in HCR group were significantly higher than those in LCR group (3.13%, 0.06±0.044) (P＜0.05) at one-year old children. The prevalence of white spot (21.67%) and dmft (0.33±0.088) in HCR group were significantly higher than those in LCR group (6.25%, 0.09±0.048) (P＜0.05) at two-year old children. The prevalence of caries (20.00%) and dmft (0.33±0.10) in HCR group were significantly higher than those in LCR group (6.25%, 0.11±0.055)(P＜0.05) at two-year old children. The detection rate of S.mutans in HCR group was significantly higher than that in LCR group at 6 months, 1-year old and 2-year old children(P＜0.05). The prevalence of dental caries (29.62%) and dmft (0.67±0.22) in children with S.mutans detected at 6 months were significantly higher than those in children without S.mutans detected (13.40%) and dmft (0.30±0.082) (P＜0.05).

After 2 years of observation, mothers with high caries risk also had higher caries susceptibility in their children. At the same time, the high risk of dental caries in mothers affected the colonization of S.mutans in children's oral cavity to a certain extent; and the earlier colonization of S.mutans, the higher risk of dental caries at 2-year old children. Therefore, intervention of oral health behaviors of mothers with high caries risk in early pregnancy can effectively prevent or reduce the occurrence and development of ECC to some extent by blocking or delaying the vertical transmission of S.mutans.