To assess family environmental factors that impact caries in children during a follow-up study for family-based community oral health promotion models.

This study was conducted from June to December 2015. A total of 200 households were selected from Jinzhou community in Nanning with the random sampling method. The data were collected through oral examinations and questionnaire surveys of family members. A logistic regression model was used to analyze the relationship between family environment factors, such as socioeconomic and family-related behaviors, and caries in children.

After adjustment for confounding factors, families in which more than 1,000 mL of sugar drinks were purchased per month; those in which the family members had a low frequency of brushing (occasionally or not); those in which the mother had a high frequency of drinking sweet drinks (more than one time each day), brushed with low frequency (less than 2 times), had no regular oral examination in the past year, or had low scores in oral health attitude and knowledge; those in which the father/mother had a low level of education (short-cycle courses and under); and those with a low annual household income (less than 50,000 RMB) had children with high rates of dental caries. Families purchasing sugar drinks >1000 mL per month were 2.22 times more likely than families purchasing sugar drinks ≤1000 mL per month to have caries in children.

Family environmental factors exert a certain influence on children's caries, and this information is a useful reference for a follow-up study.

To investigate the effectiveness of fluoride varnish in preventing first permanent molars caries inschool-age children and provide necessary information for oral health instruction.

378 children aged 6-7 years old in the first grade of primary school in dahua country, hechi city, Guangxi province (1053 first permanent molars) were randomly recruited into 2 groups. The test group (542 first permanent molars in 191 children) was treated with fluoride varnish one time in a half year and given oral hygiene instruction 3 times; The control group (511 first permanent molars in 187 children) was only given oral hygiene instruction 3 times. All first permanent molars were checked after 18 months later for caries.

After intervention, the caries prevalence rate in the test group raised from 21.99% to 27.75% compared with the control group from 24.60% to 37.43%. The caries incidence rate in test and control group was 5.76% and 12.83% respectively. There was a significant difference between 2 groups regardless of caries prevalence, caries incidence, the DMFT reduction, the DMFs reduction, the occlusal caries prevalence, the pit and fissure caries prevalence, the proximal caries prevalence.

Semi-annual application of fluoride varnish is effective in the prevention of dental caries in first permanent molars, which was worth of being popularized in clinic.