Abstract: Objective To analyze the sealing effect of the first permanent molar fossa and furrow in children aged 7-9 years in Conghua District, and explore its influencing factors. Methods Children aged 7-9 years who received the first permanent molar fossa and furrow sealing in the Fifth Affiliated Hospital of Southern Medical University from January 2019 to December 2020 were selected as the research objects. The sealing effect of the first permanent molar fossa and furrow was evaluated at 6 and 12 months after the sealing. Further univariate and multivariate analysis were used to analyze the influencing factors of occluder shedding. Results In this study, 873 patients （3 012 teeth） completed the first permanent molar fossa and furrow sealing, and the rate of occluder shedding was 10.13% and 11.95% at 6 and 12 months, respectively. Age, debris index （DI）, frequency of brushing teeth, frequency of eating desserts and carbonated drinks, and number of caries were related to occluder shedding in children aged 7-9 years in Conghua area （P < 0.05 or P < 0.01）. Multivariate stepwise Logistic regression showed that children aged 7-9 years with greater DI, frequency of taking desserts and carbonated drinks ≥ 2 times/day, and more caries surfaces had a higher risk of occluder shedding, while with older age and frequency of toothbrushing ≥ 2 times/day had a lower risk of occluder shedding after 6 months or 12 months of fossa and furrow sealing （P<0.05 or P <0.01）. Conclusions The effect of first permanent molar fossa and furrow sealing in children aged 7-9 years is related to age, oral hygiene, eating habits, number of caries, and frequency of toothbrushing. Good brushing habits and eating habits should be established to reduce the risk of occluder shedding.

Key words: Children, Permanent molar, Fossa and furrow sealing, Dental caries prevention