BACKGROUND AND OBJECTIVES: Though dental caries has a multifactorial etiology, the specific factor that results in its high rate of transmissibility is the microbial component, that is, MATERIALS AND METHODS: A retrospective analysis was done on 40 children who were divided into two groups: group I (experimental) and group II (control). Plaque samples from the children were collected by scraping the material from four index teeth using a sterile toothpick. The samples were transported to the central research laboratory for estimation of viable MS colonies on selective media TYCSB (tryptone, yeast extract, cysteine w/ sucrose, w/ bacitracin) and the VITEK RESULTS: On comparison of viable MS between varying severities of dental caries and caries-free children in the age-group 3-6 years, it was found to be below the grand median of 33 colony-forming unit (CFU) × 10 INTERPRETATION AND CONCLUSION: Multiple comparison of mean difference in MS CFU and S-IgA levels between different severities of dental caries using Tukey's HSD range test was established. HOW TO CITE THIS ARTICLE: Sharma V, Bagchi A, Dutta B,