This study aims to explore and compare the in vitro effects of Citrullus lanatus rind and pulp extracts on Streptococcus mutans. The extracts were obtained from fresh watermelon and tested at 4 different concentrations: 25 microliter, 50 microliter, 100 microliter, and 150 microliter. Four wells on each of the four MHA plates inoculated with S. mutans were filled with the respective extracts, with two plates containing the varying concentrations of each extract. The plates were then incubated at 37 °C for 24 hours, and the zones of inhibition were measured. The mean inhibition zones observed around the wells containing the pulp extract at 25, 50, 100, and 150 microliters were 27, 28, 31, and 36 mm, respectively, while the corresponding zones for the rind extract were 26, 28, 31, and 35 millimeters. Both extracts demonstrated a significant increase in antibacterial activity as the concentration rose, although no major difference was noted between the pulp and rind extracts. Based on the findings, it can be concluded that C. lanatus extracts exhibit notable antibacterial properties against S. mutans. Plant-based alternatives are increasingly being explored for their affordability, reduced side effects, and accessibility. Consequently, research is focusing on herbal and plant-derived options like C. lanatus as viable methods to enhance oral hygiene through their antimicrobial effects.
