The Influence of Flossing on the Risk of Proximal Caries in Primary Molars: A 6-Year Cohort Study

To evaluate whether flossing is associated with a lower risk of proximal caries in children's primary molars.

A longitudinal study was conducted with 122 preschool Brazilian children. Data collection occurred three times with a 3-year interval: T1, T2 and T3. At all times, questionnaires with sociodemographic and children's oral health data were answered by their parents/guardians. Oral clinical examination of the children was performed to identify the presence of caries and dental plaque.

Flossing was not associated with the incidence of dental caries in primary molars at any of the follow-up visits. The presence of visible plaque at T1 and the lack of treatment indicated after T1 were associated, respectively, with a higher incidence of proximal caries in primary molars both at T2 (RR = 1.95; 95% CI: 1.05-3.60/RR = 2.22; 95% CI: 1.18-4.18) and T3 (RR = 1.67; 95% CI: 1.12-2.49/RR = 1.87; 95% CI: 1.20-2.94). Monthly family income of less than two Brazilian minimum wages (RR = 1.74; 95% CI: 1.07-2.85) and high sucrose intake (RR = 1.56; 95% CI: 1.01-2.42) were associated with a higher incidence of proximal caries in primary molars at T3. The sample presented low statistical power, which should be considered when interpreting the findings.

Flossing is not associated with a lower risk of proximal caries in children's primary molars in the follow-up periods.