Exploring the state and influential factors of dental caries in preschool children aged 3–6 years in Xingtai City

To explore the main factors affecting early dental caries among preschool children aged 3–6 years in Xingtai City to formulate effective preventive measures. A cross-sectional study was conducted on 570 preschool children aged 3–6 years in Xingtai City through questionnaire surveys and oral examinations to understand their dental caries situation. Multifactorial logistic regression analysis was used to analyse the main influencing factors for the occurrence of dental caries in preschool children. Univariate analysis showed statistically significant differences in age (χ2 = 2.636, p = 0.008), father's education level (χ2 = 4.207, p < 0.001), mother's education level (χ2 = 4.217, p < 0.001), daily tooth brushing frequency (χ2 = 3.160, p = 0.002), age of starting tooth brushing (χ2 = 8.756, p < 0.001), mouth rinsing after meals (χ2 = 89.401, p < 0.001), Streptococcus mutans positivity (χ2 = 133.503, p < 0.001), non-sweet snack consumption frequency (χ2 = 5.962, p < 0.001), snack flavour preference (χ2 = 116.119, p < 0.001), use of fluoridated toothpaste (χ2 = 75.639, p < 0.001), regular oral examinations (χ2 = 98.711, p < 0.001), sugary drink consumption frequency (χ2 = 10.370, p < 0.001) and sweet food consumption frequency (χ2 = 9.261, p < 0.001) between the caries and non-caries groups. Multifactorial analysis revealed that older age (odds ratio OR = 5.342, 95% confidence interval CI: 1.434–6.631), later initiation of tooth brushing (OR = 3.244, 95% CI: 2.413–5.424), S. mutans positivity (OR = 5.357, 95% CI: 4.529–8.563), high snack consumption frequency (OR = 3.452, 95% CI: 2.634–5.442), high sugary drink consumption frequency (OR = 4.414, 95% CI: 2.534–6.451) and high sweet food consumption frequency (OR = 4.531, 95% CI: 3.421–6.354) were risk factors for dental caries. Higher father's educational level (OR = 0.724, 95% CI: 0.564–0.891), higher mother's educational level (OR = 0.641, 95% CI: 0.601–0.813), high daily tooth brushing frequency (OR = 0.572, 95% CI: 0.423–0.864), mouth rinsing after meals (OR = 0.743, 95% CI: 0.643–0.813), use of fluoridated toothpaste (OR = 0.657, 95% CI: 0.553–0.931) and regular oral examinations (OR = 0.443, 95% CI: 0.352–0.747) were protective factors against dental caries (all p < 0.05). Multiple factors result in early dental caries in preschool children aged 3–6 years; however, the most influential factors are older age and high snack consumption, as well as high sugary and sweet food/drink consumption.