To compare the objective brushing data recorded by the smart electric toothbrushes with the participants′ self-reported brushing behaviors, and to analyze the differences in brushing habits reflected by the two and their influencing factors.

A total of 18 169 users aged 18-45 years old who used the same smart electric toothbrushes between January and December 2024 were included as study subjects. Data on brushing behaviors (average daily brushing frequency, single brushing duration) were obtained through smart electric toothbrush recordings and participant self-reports by filling out questionnaires, and were statistically analyzed using Kappa consistency test, chi-square test, and binary logistic regression.

Among the participants, 9 864 individuals (54.3%) reported brushing habits consistent with those recorded by the smart toothbrush, while the remaining 8 305 individuals (45.7%) exhibited inconsistencies. This difference was statistically significant (κ = 0.106, P<0.001), with 92.8% (7 711/8 305) of the inconsistent group being overestimators of their subjective behavior. Among study participants who self-reported periodontal symptoms, the proportion of those who underestimated their subjective behavior was 8.1%, higher than those without periodontal symptoms (6.6%) (χ² = 6.332, P = 0.012). Binary logistic regression analysis showed that participants with periodontal symptoms were 1.224 times more likely to underestimate their brushing behavior than those without periodontal symptoms (OR = 1.224, 95% CI: 1.032 ~ 1.453, P = 0.02) .

Individuals′ perception of their brushing behavior deviates significantly from the actual situation, and individuals tend to overestimate their actual toothbrushing behavior. The occurrence of periodontal symptoms makes individuals improve the accuracy of their perception of brushing behavior. Smart electric toothbrushes can help users correct cognitive bias and improve oral health management through mechanisms such as objective data feedback.