Background <p>Dental caries (DC) is a significant common disease of the oral cavity. Recently, researchers have focused more on the impact of poor sleep habits on the incidence and development of DC, which aroused our interest in the study of the correlation and causal relationship between sleep and dental caries.</p> Methods <p>In this study, Linkage disequilibrium score (LDSC) regression method was used to found the genetic correlation between different sleep traits and DC, while bidirectional Mendelian randomization (MR) methods were used to explore the causal relationship. The main analysis of MR was inverse variance weighted method, and the outcomes were evaluated by odds ratio (OR) and 95% confidence interval (95% CI).</p> Results <p>In LDSC regression analysis, genetic correlations were found between chronotype, dozing, insomnia, sleep duration and DC (<i>P</i> = 0.002, <i>P</i> = 0.026,<i> P</i> = 7.233E-09, <i>P</i> = 0.012). However, when utilizing the TSMR method, no discernible casual relationships were found between chronotype, dozing, insomnia, sleep duration and DC (<i>P</i> = 0.832, <i>P</i> = 0.129, <i>P</i> = 0.822, <i>P</i> = 0.644). This result was further substantiated through the utilization of additional validation datasets.</p> Conclusions <p>Our study found no causal relationship between sleep traits and DC.</p>