Dental caries is a preventable childhood disease and a significant public health problem globally.[1] A multi-factorial biofilm-mediated disease caused by oral bacteria consuming dietary sugars and generating acids that are able to demineralize oral hard tissues over time.[2] . Dental caries is a significant health problem that disproportionately affects children and is largely preventable with the appropriate exposure to fluoride, oral hygiene, dietary modification, and timely dental care, but has been seen in low- and middle-income countries where preventive and restorative dental services may be limited.[3]

The school-age population is an especially important group to study dental caries because it spans the period of transition from primary to permanent dentition and the laying down of lifelong lifestyle habits.[4] Children's eating habits directly affect caries.[5] Eating free sugar, sweetened drinks, sweets, and other sugary snack foods and foods that present acid challenges to the teeth raises the number and the length of time that the acid is present in the mouth.[6] In a systematic review of longitudinal studies, children who consumed fruit juice as well as candy, soft drinks, and sweetened beverages were seen to have an increase in dental caries, particularly at night.[7] However, recent studies have also indicated a relationship between consumption of ultra-processed foods and dental caries in children and adolescents, highlighting the need for a focus on diet patterns rather than individual foods.[8]

Meanwhile, children's lives have also transformed significantly since the era of television, the smartphone, tablet, computer, and other digital devices.[9] However, screen time is a growing part of kids' behaviors, and a systematic review revealed that children aged 6 to 14 years expose themselves to a lot of screen-based activities.[10] Excessive screen time can negatively affect oral health in several ways, such as substituting physical activity, disturbing sleep and mealtimes, stoking binge eating of snacks, and increasing the likelihood of being exposed to food- or beverage-related advertisements.[11] Importantly, previous evidence has shown an association between increased TV viewing or total screen-time and poor dietary patterns such as increased intake of energy-dense snack foods and sugar-sweetened beverages.[12]

Therefore, the present study was planned to see the relationship between screen time, nutrition behavior, and dental caries among school-going children. The study will assess screen time in addition to frequency and type of food and beverage consumption and caries experience to determine potential modifiable behavioral factors contributing to poor oral health. The premise is straightforward, yet more and more applicable: Today, children spend the bulk of their time on screens and screen-related snacking, so stopping dental caries might not only involve looking inside the child's mouth, but also in how children spend and eat their time. The results could serve as evidence to support integrated interventions designed to encourage healthier screen-use habits and dietary patterns to enhance oral health among school-age children for parents, schools, dental care providers, and public-health policymakers. The current study was designed to explore the relationship between screen time, dietary behaviors, and caries experience in school-aged children, and to identify the behavioral factors associated with higher caries experience.

This was an analytical cross-sectional study conducted in a school setting to ascertain the association between screen time, dietary habits, and dental caries among school children. The study was conducted among Department of Paediatric dentistry. The study was conducted over a period of six months, From October, 2025 to March 2026. The sample size was computed using the OpenEpi online calculator based on an expected prevalence of dental caries of 88.7%, 95% confidence level, and 5% absolute precision.[13] The sample size was increased to around 337 participants to make up for a 10% anticipated non-response or incomplete-data rate. Hence, the final sample of 340 school-aged children was recruited. A multistage sampling technique was used. Firstly, the schools were chosen from the study area based on the consent of the relevant school authorities. All children enrolled in the selected schools during the study period were included (6-14 years). Children were eligible for the study if they had been attending the school for at least 3 months, if they could comprehend and answer the study questionnaire with age-appropriate support, and if they were available for clinical oral examination. Parents/legal guardians gave written informed consent, and participating children gave verbal or informed consent as appropriate based on age and institutional ethical standards. Children who had any systemic disorders or developmental conditions that significantly impacted oral health or nutrition were not included. Children with more extensive dental treatment or orthodontic treatment that would be likely to affect the assessment of dental caries were also excluded. Medications that had an established effect on salivary flow or oral health were excluded, as well as very ill individuals at the time of examination and children whose parents/guardians did not sign the consent. Children who did not complete the questionnaires or those who were not able to have a clinical dental evaluation were also omitted from the final analysis. A structured questionnaire was administered to the children, with the help of their parents/guardians as needed, to gather data. The data on screen time was collected by asking about the amount of time spent viewing television and on mobile devices such as smartphones, tablets, computers, game systems, and other digital screens per day. Screen exposure data was collected separately for weekdays and weekends when possible. Total daily screen time was divided into "less than two hours" and "two hours or more" screen time per day for analysis. Other data were collected on the use of a screen during meals, snack consumption in front of screens, and as to what type of screen device the child used the majority of the time. The dietary behaviours were evaluated by questions about the frequency of intake of potentially cariogenic food and beverages. The information gathered included that on sugar-sweetened beverages, carbonated drinks, packaged juices, confectionery, chocolates, biscuits, cakes, candies, sweetened tea, fast food, and other processed snacks. Children were also questioned on how often they ate fruits and vegetables, breakfast, between-meal snacking, and eating sugary foods before going to bed. Dietary behaviour was then divided by the number of times foods and drinks that cause cavities were eaten. Toothbrushing frequency, use of fluoride toothpaste, brushing before going to bed, supervision of parents at toothbrushing, and previous visits to the dentist were evaluated as oral hygiene practices. Following this, the children were then clinically examined by a trained dental examiner under proper illumination and with the help of a sterile mouth mirror and proper examination instruments. The Decayed, Missing, and Filled Teeth index (DMFT) was used to assess dental caries for permanent dentition, and for primary dentition, the decayed, extracted, and filled teeth index (DEFT) was used as appropriate for the child's dentition. The examiner was calibrated before the beginning of data collection to improve consistency in the caries assessment. All participants were administered the same examination procedure. The collected data were entered, cleaned, and analyzed by IBM SPSS Statistics software. Continuous variables like age, daily screen time, and DMFT/deft scores were tested for normality by the Shapiro–Wilk test and presented as mean ± SD or median (IQR) depending on the results of normality testing. All the categorical variables such as sex, school type, screen-time category, categorised frequency of sugary food consumption, toothbrushing frequency, and the presence or absence of dental caries were summarised as frequencies and percentages. The association between categorical variables was tested by using the chi-square test, and Fisher's exact test when the expectation cell frequencies were low. Independent-samples t-test and Mann–Whitney U test were used to compare continuous variables between two groups, depending on the distribution of the data. Pearson's or Spearman's correlation coefficient (depending on its value) was used to test the correlation between daily screen time, frequency of consumption of cariogenic foods, and DMFT/deft scores. To determine the independent factors associated with dental caries, multivariable binary logistic regression analysis was performed. The dependent variable was dental caries status, and the potential explanatory variables included screen time, frequency of eating sugary foods, eating in front of the screen, age, sex, type of school, socioeconomic status, and the frequency with which children brush their teeth and visit the dentist. Adjusted odds ratios (AORs) with 95% confidence intervals (CIs) were reported. Clinically relevant associations and/or important results from the univariable analysis were taken into account for inclusion in the multivariable model. The problem of multicollinearity was pretested prior to the construction of the final model. A two-tailed p-value <0.05 was deemed statistically significant.

The mean age of the 340 school-aged children was 10.6 ± 2.4 years, with the majority being 10–12 years (40.9%). 53.5% of the sample were boys and 57.6% were attending public schools. The majority of children came from the middle socioeconomic status (MSS) (51.2%), and 42.1% of children had parents with a graduate degree or higher. The mean BMI was 18.9 ± 3.1 kg/m². Of the individuals who brushed their teeth at least twice a day, 67.4% did so before bedtime; of those who used fluoride toothpaste, 40.3% had been to a dentist before. Overall, 71.8% of the participants had dental caries, with a mean DMFT/deft score of 2.71 ± 2.18. (Table 1)

Children's screen exposure was relatively high, with 65.9% of children reporting ≥2 hours per day. 61.2% reported watching TV for ≥1 hour/day, and 56.5% reported using a smartphone or tablet for ≥1 hour/day. Children who spent ≥2 hours a day on screens had significantly more dental caries than those who spent <2 hours a day (p≤0.003); those who used smartphones/tablets ≥1 hour per day had significantly more dental caries than those who used them <1 hour per day (p≤0.003); and those with ≥1 hour of TV viewing per day had significantly more dental caries than those with <1 hour per day TV viewing (p≤0.003). Screen use during meals and snacking while using screens was also significantly associated with caries (both p<0.001). (Table 2)

There were significant associations between dental caries and dietary behaviors. Dietary behaviors were significantly associated with dental caries. The higher the frequency of the consumption of sugary foods, the higher was the prevalence of caries among children, ranging from 55.9% among children who consumed sugary foods less than once a day to 86.3% among children who consumed sugary foods at least three times a day (p<0.001). The same pattern has been seen with the frequency of sugar-sweetened beverages consumed each day, consuming confectionery or chocolate frequently, and consuming packaged snacks frequently (all p<0.001), as well as with the amount of sugary foods consumed before sleep at night (p<0.001). Additionally, children who had <1 serving of fruit and veg per day were significantly more likely to have caries prevalence compared to children who had at least 1 serving per day (82.9% vs. 64.9%, p=0.001). (Table 3)

The dental caries group was slightly older than the non-dental caries group (10.8 ± 2.3 years vs. 10.1 ± 2.5 years; p=0.018), but there was no significant difference between the BMI of the groups. The children with caries had significantly higher daily screen time, exposure to sugary foods, intake of sugar-sweetened beverages, and DMFT/deft scores (all p<0.001) than the control children, as shown by median-distribution comparisons. The mean DMFT/deft score was 3.31 ± 2.12 in children with caries, whereas it was 1.18 ± 1.06 in children without caries. (Table 4)

The daily screen time was found to have a significant positive correlation with DMFT/deft score (r=0.34, p<0.001). Sugary-food exposure showed the highest positive correlation (r=0.46, p<0.001), followed by sugar-sweetened beverage (SSB) exposure (r=0.31, p<0.001), packaged snack (PS) exposure (r=0.29, p<0.001), and screen during meals (SDM) (r=0.25, p<0.001). In contrast, there were significant negative correlations between toothbrushing frequency and DMFT/deft scores (r=−0.22, p<0.001), and between fruit/vegetable consumption and DMFT/deft scores (p=0.001). (Table 5)

Dental caries was found to have multiple independent predictors by multivariable logistic regression. The odds of caries increased with age (p=0.017, per additional year of age). Children with ≥2 hours of daily screen time were over two times more likely to have caries (p=0.001), and screen time at meals (p=0.017) and snacking while watching screens (p=0.003) were independently associated with caries. The daily consumption of sugared foods ≥3 times/day was most strongly associated (p<0.001), followed by the daily consumption of sugar-sweetened beverages (p=0.004) and sugared food before bedtime (p=0.022) among dietary factors. Brushing more than twice a day, on the other hand, had a protective association with caries (p=0.019). There was no independent relationship of sex, type of school, socioeconomic status, or previous dental visits with the caries status. (Table 6)

Table 1. Sociodemographic, anthropometric, and oral-hygiene characteristics of the participants (n=340)

Table 2. Screen-time characteristics of the participants and association with dental caries

Table 3. Dietary habits and their association with dental caries

Table 4. Comparison of screen time, dietary factors, and DMFT/deft scores according to dental caries status

Table 5. Correlation of screen time and dietary variables with DMFT/deft score

Table 6. Multivariable logistic regression analysis of factors associated with dental caries

The present study showed a high prevalence of dental caries among school-going children, with 71.8% of affected children and a mean DMFT/deft score of 2.71 ± 2.18. The main results of the study showed that long exposure to screens and poor dietary habits significantly contributed to dental caries. Children who watched ≥2 hours of daily screen time had a significantly higher prevalence of caries (79.0% vs. 57.8%, p<0.001) and sugar-sweetened soft drinks, sugar-sweetened snacks, sugary foods before bed, and frequent consumption of sugary foods were significantly associated with caries. Most importantly, these associations remained after adjusting for age, sex, school type, socioeconomic status, oral hygiene practices, and dental visits, indicating that screen-related behaviors and dietary habits may be important modifiable factors in childhood caries risk. The current study's prevalence of dental caries showed a higher rate than that reported by Wang et al. (2023) in 11,351 adolescents aged 12-15 years in Shanxi, China, with a prevalence of 44.57% and a mean DMFT of 0.98 + 1.49. Despite this, their study showed that diet patterns had a significant effect on caries risk, with an increased risk of caries associated with a refreshing foods diet pattern and a protective association with a coarse-grain rich diet pattern.[14] Differences in age structure, socioeconomic factors, fluoride exposure, diet, and access to dental care and oral-health behavior may all be associated with the increased caries burden seen in our population. However, there is consistency in the direction of the dietary association, which lends evidence that overall dietary patterns are important factors affecting children's oral health. Our results on the impact of screen time on oral health were especially consistent with the study conducted by Garg et al. (2023) on direct exposure to screen time, consumption of cariogenic foods and oral health among school children aged 8–14 years in Delhi, India. In that study, 88.7% of children reported ≥2 hours of screen exposure, and children with ≥2 hours had significantly higher DMFT/deft scores compared to children with <2 hours (p=0.001). These children also had lower plaque and gingival-health indices with higher screen exposure.[13] The fact that a large and significant DMFT/deft burden was found in children with ≥2 hours of screen time therefore adds to the growing evidence that exposure to screens for longer periods may have relevance to oral health, and not only be a proxy indicator of sedentary time. In a cross-sectional study from 2024, 353 children aged 6–13 years were assessed for their screen time and diets, revealing a comparable connection between oral health and screen time. That research indicates that 18.7% of children consumed more than 2 hours of screen time on weekdays and 78.2% on weekends. Most importantly, total screen time was significantly positively correlated with cavitated carious lesions (Spearman r=0.140, p=0.004), as were the number and percentage of meals eaten while watching screens with total caries and cavitated carious lesions.[15] Our results were similar, with those who used screens at mealtimes being more likely to have caries than those who did not (81.0% vs. 60.3%, p<0.001), and screen use being an independent risk factor for caries after adjusting for other factors (AOR=1.87, 95% CI 1.12–3.12). These results collectively suggest that the type and content of media use, specifically while eating on the screen, may outweigh media exposure as a predictor. A population-based study by Bomfim et al. (2021) in 615 12-year-old Brazilian children attending public schools also showed a relationship between sedentary lifestyle, unhealthy diet and dental caries. In their study, they discovered a mean DMFT of 1.02 and 39.1% of caries experience. A decrease in DMFT was associated with lower sedentary behavior in children who consumed ≤2 hours per day, and unhealthy food consumption was also significantly associated with caries. Indeed, unhealthy food consumption between sedentary behavior and DMFT was mediated.[16] These findings are of particular interest since the children who snacked on the screens were found to have significantly higher prevalence of dental caries, and snacking during screen use was still independently associated with dental caries. So, the relationship between screen time and caries can't just be “more screen time, more caries” but could be “more screen time, more eating snacks, more eating cariogenic food.” The dietary findings of the current study were in line with Mahboobi et al. (2021), who carried out a systematic review of the longitudinal data on free-sugar intake and dental caries in children aged 6–12 years. They determined that daily fruit juice intake, consuming candy more often than once per week, and soft or sweet beverages at bedtime were significantly related to dental caries. Some studies report water and dairy products as being potentially protective.[17] The prevalence of caries was very similar across the groups: children who consumed sugary food items ≥3 times daily had an 86.3% prevalence of caries, while consuming sugary foods before bedtime was independently associated with caries. This reinforces the idea that sugar exposure, rather than just the amount, should be considered in terms of frequency and timing, especially in children developing caries. Additional support was provided by Tilton et al. (2021), who investigated nutrition habits of children with various clinical presentations of primary dentition caries. The clusters that they found relate to the frequency of water and cariogenic solid, soft, and liquid foods consumed, respectively. Children with anterior carious lesions were more likely than caries-free children to have a pattern of regular intake of both fruit juice and cereal bar.[18] These results corroborate our findings that some food groups such as sweetened beverages and packaged snacks were found to be associated with caries. Overall, the data suggest that dietary assessment that relies on general patterns and eating behavior may be more effective at predicting caries risk than does the assessment of any individual food item. The results of our study on sugar-sweetened beverages also corroborated with a 2024 study in Nonthaburi Province, Thailand, conducted on 400 primary school students from 10 to 12 years of age. There was a prevalence of dental caries of 62.5%, and sugar-sweetened beverages consumption >3 times a week was significantly associated with dental caries (p<0.001). Poor toothbrushing and poor parent education were also independently related to caries.[19] Our study also revealed that children who drank sugar-sweetened beverages at least once a day had a significantly higher prevalence of caries and were more than twice as likely to have caries (p = 0.004). The difference in exposure thresholds can partly account for the different effect estimates, but both studies suggest that sugar-sweetened drinks are an important and potentially modifiable risk factor. A more recent study by Cassano et al. (2025) corroborates the behavioral dimension we found in our study. They examined children between the ages of 2–12 years cross-sectionally to measure their screentime, unhealthy food intake, and caries experience. The mean screen time was 5.35 ± 2.01 hours/day and over half of the children ate unhealthy foods more than four times a day. The study was conceptually similar to ours, although much smaller in sample size, providing further support to the need to look at screen time and unhealthy food intake together to understand the problem of child caries.[20] Overall, the results indicate that screen time and diet are more closely linked behavioral risk factors for children's oral health than they are distinct exposures. This study contributes to the existing evidence that sedentary behavior, screen-associated eating, free sugar consumption, sugar-sweetened beverages and ultra-processed foods are all associated with increased caries experience. We found that these relationships did not change significantly after controlling for sociodemographic and oral-hygiene characteristics, a result of which is particularly interesting. This implies that preventive dental programs should extend beyond the dental chair and consider the child's other daily activities, including viewing programs, viewing food served during the program, and how often their teeth are exposed to cariogenic foods and beverages while viewing. Limitations There were some limitations in the study. First, its cross-sectional design did not allow for the establishment of any temporal or causal relationships between screen time, dietary habits and dental caries. Second, data on screen exposure, food consumption and oral hygiene habits were self-reported and may have been subject to recall and social-desirability bias. Thirdly, the study was carried out in selected schools in a limited geographical area that may limit the generalizability of the findings to all school age children. Assessment of detailed information regarding fluoride exposure, genetic susceptibility, parental feeding practices, and nutritional composition of individual foods was not assessed. Lastly, the potential confounding factors were controlled in the multivariable analysis, but residual confounding was not ruled out.

This study revealed a high prevalence of dental caries among school-age children and showed that extended screen time and poor food choices were significant factors related to dental caries. Frequent intake of sugary foods and sugary drinks, screen use at meal times, screen snacking, and the use of screens for two hours or more per day were each independently associated with higher odds of dental caries. Consumption of sugary food before sleep was also independently associated with higher odds of dental caries. Conversely, toothbrushing at least once a day was correlated with a reduced risk of caries. These results indicate that oral-health promotion in childhood should not be limited to dental hygiene and should include lifestyle behaviors. Toothbrushing, eating healthier snacks, avoiding screen time, avoiding screen time during meals, and parent/school-based interventions in the school can all help to decrease the burden of dental caries.

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