This study used cluster sampling to select hepatitis B patients from a tertiary hospital in Beijing between March and April 2025. Based on the sample size calculation method for cross-sectional studies (5–10 times the number of independent variables), and considering 33 influencing factors and a 10% invalid questionnaire rate, the required sample size was 182–363 patients.

A questionnaire was designed for this study, referencing the 4th National Oral Health Epidemiological Survey for adults and tailored to the study objectives. It included 33 questions on basic information, oral hygiene behaviors, sweet food habits, oral health knowledge, attitudes toward oral care, and experiences with toothaches and dental visits. Trained investigators distributed the questionnaires, explained their purpose and completion guidelines, and collected responses on-site, ensuring completeness and validity.

All statistical analyses were performed using SPSS 22.0 software(P < 0.05). Continuous data were described using means ± standard deviations and analyzed with u-tests. Categorical data were analyzed using chi-square tests, and ordinal data were analyzed with rank-sum tests.

A total of 361 valid questionnaires were collected. Respondents included 244 males and 117 females; 230 respondents (63.7%) were from urban areas and 131 (36.3%) respondents were from rural areas. Of the participants, 200 (55.4%) were with a high school education experience or lower educational background, and 161 (44.6%) had college or higher education. 160 respondents (45.6%) were 50 years old or younger, and 201 (55.7%) respondents were older than 50.

Oral hygiene behaviors were assessed based on tooth-brushing habits, dental floss using, and fluoride toothpaste using. Good tooth-brushing habits were defined as brushing at least twice daily. Results showed that 232 (64.27%) had good tooth-brushing habits, 44 (12.12%) used dental floss regularly, and 109 (30.19%) explicitly used fluoride toothpaste. Additionally, 190 (52.6%) were unaware whether their toothpaste contained fluoride.

Sweet food habits mainly include: 1) pastries (cookies, cakes, bread) and candies (chocolate, sugary gum); 2) sweet drinks (carbonated beverages and fruit juices); 3) milk, yogurt, powdered milk, tea, soy milk, and coffee with added sugar. Among the survey participants, 33 people (9.2%) consume pastries and candies daily, 17 (4.7%) drink sweet beverages daily, and 27 (7.5%) consume sugary dairy products or coffee daily.

The results of the rank sum test are shown in Table 2: In terms of the frequency of consuming sweet pastries and candies, those with a high school education or above have higher rates than those with a high school education or below, and those over 50 years old have higher rates than those 50 years old or younger; regarding the frequency of consuming sweet beverages, those with a high school education or above have higher rates than those with a high school education or below, and those over 50 years old have higher rates than those 50 years old or younger; concerning the frequency of consuming sugary dairy products and coffee, those with a high school education or above have higher rates than those with a high school education or below, and those over 50 years old have higher rates than those 50 years old or younger; all these differences are statistically significant (P ≤ 0.05). The proportion of patients with fatty liver disease in this study is 10.25%.

The oral health knowledge test consists of 8 questions, each worth 1 point, with an overall score of 4.31 ± 1.55 and an average correct rate of 53.9%. The correct rates for each question aThe oral health knowledge test consists of 8 questions, each worth 1 point, with an overall score of 4.31 ± 1.55 and an average correct rate of 53.9%. The correct rates for each question are shown in Table 3. Through u-test analysis, the score for males was 4.22 ± 1.49, and for females, it was 4.5 ± 1.65, indicating that females scored higher than males, with a statistically significant difference (Z=-2.107, P = 0.035). The score for urban areas was 4.47 ± 1.47, and for rural areas, it was 4.02 ± 1.64, suggesting that urban areas scored higher than rural areas, with a statistically significant difference (Z=-2.579, P = 0.010). For those with high school education or below, the score was 3.98 ± 1.62, and for those with higher education, it was 4.71 ± 1.36, indicating that higher education scores were higher than those with lower education, with a statistically significant difference (Z=-4.568, P = 0.000). For those aged 50 or younger, the score was 4.43 ± 1.55, and for those over 50, it was 4.21 ± 1.54, showing no statistically significant difference (Z=-1.571, P = 0.116).

The analysis of oral health attitudes consists of 4 questions, each worth 1 point, with an overall score of 3.37 ± 0.942, and an average positive attitude of 83.7%. The accuracy rates for each question are shown in Table 4. Male scores were 3.41 ± 0.88, higher than female scores of 3.26 ± 1.06, with no statistically significant difference (Z=-1.030, P = 0.303); rural scores were 3.21 ± 1.07, lower than urban scores of 3.46 ± 0.85, with a statistically significant regional difference (Z=-2.325, P = 0.020); high school and below scores were 3.2 ± 1.03, lower than high school and above scores of 3.57 ± 0.78, with a statistically significant educational difference (Z=-4.099, P = 0.000); scores for those aged 50 and under were 3.48 ± 0.88, higher than those over 50, with a statistically significant difference (Z=-2.355, P = 0.019).

The comparison of medical-seeking behaviors among different groups is shown in Table 5, with 77.3% (279 people) having a history of dental visits, and 22.7% (82 people) having never had a dental visit. According to the chi-square test, the proportion of those over 50 years old who have had dental visits is higher than that of those 50 and under. There were no statistically significant differences among gender, place of residence, and educational level.

This study shows that girls have better tooth-brushing habits than boys, which may be related to women's higher oral health needs ^[7]; in terms of oral health knowledge, women score higher than men, consistent with the research by Jassem Al-Ansari et al^[8]. Additionally,,Abed Al-Hadi Hamasha^[9]et al.' s study indicates that because women place more emphasis on their appearance and beauty compared to men, they generally pay more attention to the aesthetics of their teeth^[10]and value their smiles ^[11]. The more they visit the dentist, the more opportunities they have to receive education on health issues and gain knowledge ^[12]. Therefore, as they continue to accumulate knowledge about dental health, they tend to be more willing to adopt better oral health behaviors ^[13].

This study shows that urban residents have better tooth-brushing habits than rural residents, which may be related to economic and cultural differences between regions ^[14]; urban residents score higher in knowledge than rural residents, possibly because urban residents have easier access to oral health information ^[15]. In terms of attitudes towards oral health care, this study also indicates that urban residents have better attitudes than rural residents, consistent with the findings of Huabin Luo et al., who found poorer awareness of oral prevention among rural residents^[16]. Additionally, the demand for dental restoration is lower in rural areas ^[17–19]due to financial barriers and a shortage of dentists ^[20]. Urban residents generally have higher economic capabilities ^{[21, 22]}, thus they have more opportunities to obtain proper oral health care. Furthermore, it may be that older rural residents have more negative perceptions of oral health compared to their urban counterparts ^[23], leading to more pessimistic attitudes towards health care.

This study shows that 64.72% of the population has good tooth brushing habits, with those aged 50 and above accounting for 55.7%, a significant increase compared to the 30.6% in the 55–64 age group from China's fourth epidemiological survey. This may be related to the increased likelihood of gum bleeding due to the presence of HBsAg^{[24, 25]}. Additionally, this study indicates that patients believe increasing the frequency of brushing can reduce gum bleeding. This finding is consistent with the results of surveys by Zhao Xiaolang ^[26]et al. Therefore, the tooth brushing rate among hepatitis B patients in this survey is notably higher than that of the same age group nationwide.

In addition, the survey results show that the usage rate of dental floss is 12.12%, which is higher than the 2.1% reported in the fourth national epidemiological survey, but the penetration rate remains low. This finding aligns with the conclusions drawn by Li Weijia et al^[27]. The reasons for this may include insufficient awareness among older audiences about the necessity of interdental cleaning and a lack of channels to learn how to clean between teeth. It could also be due to the relatively low prevalence of dental floss use in China and the concern among most residents that using dental floss might widen the gaps between teeth or even cause tooth loosening ^[28].

This study shows that in terms of medical visits, the proportion of dental visits among those over 50 years old is higher than that of those under 50. W M Thomson's^[29] review indicates that compared to younger people, older adults have a higher incidence of dental caries. Additionally, the reduction in tooth number can lead to decreased chewing efficiency ^{[30, 31]}, which affects the nutrition and health of older adults ^{[32, 33]}. Therefore, the proportion of dental visits among older adults is relatively higher.

This study showed that the higher the education level, the higher the consumption rate of sweets, which may be related to their high work pressure^{[34, 35]}and lack of sleep ^[36]. However, the effect of sweets on liver needs to be further explored.

This study also shows that 83.7% of people have a positive attitude towards oral health care, indicating that the attitude of hepatitis B patients towards oral health care is above average, similar to the findings of Liao Xin et al^[37]. The higher people's education level, the better their grasp and use of oral health knowledge ^[38–40]. Moreover, the social gradient formed by social stratification and social inequality mechanisms ^[41] is considered an important issue affecting oral health ^[42], as higher education levels are associated with higher household monthly incomes, while those with lower education levels have lower incomes. Additionally, residents with lower education levels may not receive appropriate oral hygiene maintenance training, thus they may not realize the importance of regular dental check-ups ^[23].

In summary, the results of this study indicate that patients with hepatitis B generally have good oral health awareness, attitudes, and behaviors. However, there are still differences among regions, educational levels, and economic income. Therefore, we need to strengthen oral health education for patients in rural areas and those with lower educational backgrounds. Additionally, this is a single-center study that was not conducted nationwide, and the age groups span too wide, lacking sufficient detail. Further research is needed on the relationship between sweets and liver function.