Objective      To investigate the prevalence and related factors of the first permanent molar caries in 7- to 9-year-old children in Three Gorges immigrants of Wanzhou District

Chongqing

China in 2012.       Methods      An overall sampling method was used

including 3 927 7- to 9-year-old children of Three Gorges immigrants in 6 immigrant primary schools in Wanzhou District of Chongqing

China. The caries of the first permanent molar was assessed. The collected data were statistically analyzed. A structured questionnaire including oral hygiene habits and oral health knowledge was used.       Results 

     The study sample included 3 927 school children. The total prevalence rate of the first permanent molar caries was 39.2%

the caries mean was 0.96

and caries filling rate of the first permanent molar was 9.4%. In 7-

8-

and 9-year-old groups

the prevalence rates of the first permanent molar caries were 20.5%

36.5%

and 58.7%

respectively

while the caries means were 0.36

0.88

and 1.65

respectively. There were statistically significant differences between different age groups (

P

0.05). Logistic regression analysis showed that parenting

the frequency of teeth brushing

and the frequency of sugar food intake were closely related to the caries prevalence of the first permanent molar in 7- to 9-year-old children of Three Gorges immigrants of Wanzhou District

Chongqing

China.       Conclusion      The prevalence rate of the first permanent molar caries in 7- to 9-year-old children of Three Gorges immigrants is high

but the caries filling rate is low. Oral health awareness and oral hygiene habits are poor. Oral health education and oral health interventions need to be strengthened.