<![CDATA[Background: Dental caries remains one of the most prevalent chronic diseases in Indonesia and is associated with changes in the oral microbiota. Lactobacillus sp. is bacteria that contribute to caries progression and is found as microbiological indicators of caries activity. However, data regarding the relationship between salivary Lactobacillus sp. counts and caries severity in boarding school students remain limited. This study aims to determine the relationship between salivary Lactobacillus sp. colony counts and caries severity using DMF-T index among female students in boarding school.Method: An analytical observational study with a cross-sectional design was conducted among 28 female students. Caries severity was assessed using DMF-T index and categorized into mild (0-2), moderate (3-4), and severe (>5). Unstimulated saliva samples were collected and cultured on MRS agar. Samples were incubated anaerobically, and colony counts were counted. The association between colony count and DMFT category was analyzed using Spearman’s rank correlation test, while differences among DMF-T categories were evaluated using the Kruskal–Wallis and Mann–Whitney U tests.Result: A significant positive correlation was observed between Lactobacillus sp. colony count and DMFT index (r=0.443; p=0.018). The Kruskal–Wallis test showed significant differences in Lactobacillus sp. counts among DMFT categories (p = 0.018). Significant differences in bacterial counts were observed between severe and both mild (p = 0.013) and moderate (p = 0.017) caries index, but not between mild and moderate index (p = 0.718).Conclusion: Salivary Lactobacillus sp. colony counts were significantly associated with dental caries severity among female boarding school students]]>
