Background: The effectiveness of fluoride in caries prevention isenhanced by its ability to reduce demineralization, promote remineralization, and antibacterial properties against streptococcus mutans. Interestingly, Gum Arabic has a remineralization effect similar to that of sodium fluoride.
 Objectives: This study aimed to investigate the antibacterial activity of Gum Arabic processed by two methods against Streptococcus mutans and compare it to the antibacterial activity of various concentrations of sodium fluoride in order to compare their caries prevention capability.
 Design: Antibacterial susceptibility tests for 200mg ethanolic extracts of mechanically ground and spray-dried Gum Arabic, as well as sodium fluoride at concentrations of 0.05% and 1.23% against S. mutans (ATCC 25175) were performed using the agar disc diffusion method. Chlorhexidine and Antibiotic multi-disc for gram-positive bacteria were used as positive controls, while ethanol 20% as a negative control. The diameters of the inhibition zones were measured for all the materials under investigation.
 Results: The diameters of the inhibition zones of the spray-dried and the mechanically ground Gum Arabic were (10.67 mm & 9.67mm), respectively, almost approximating each other. In comparison, sodium fluoride (0.05% wash and 1.23% gel) showed inhibition zones of diameters (0mm& 2.33mm), respectively.
 Gum Arabic, with both processing methods, exhibited significantly higher antibacterial activity against S. mutans than sodium fluoride (0.05%, 1.23%)
 Conclusion: Gum Arabic, either mechanically ground or spray-dried, is a partially active antibacterial against S. mutans. Gum Arabic is a more potent antibacterial against S. mutans than sodium fluoride.
 Keywords: Gum Arabic, Anti-caries, Sodium fluoride, Streptococcus mutans, Antibacterial activity