eng Oriental Scientific Publishing Company Biomedical and Pharmacology Journal 0974-6242 2024-03-20 17 1 281 290 10.13005/bpj/2856 56404 article Essie Octiara 1 Asima Larasati Sipangkar 2 Lora Prist 2 Department of Pediatric Dentistry Faculty of Dentistry, Universitas Sumatera Utara, Medan, Indonesia. Faculty of Dentistry, Universitas Sumatera Utara, Medan, Indonesia. Background: S.mutans is the main pathogen causing caries, while E.faecalis is the dominant microorganism in dental root canals. Batak onion is one of Indonesia's biological resources frequently used as condiments by Batak tribes and possesses antibacterial compounds such as alkaloids, saponins, and flavonoids. Aims: To analyze antibacterial activity test based on Minimum Inhibitory Concentration (MIC), Minimum Bactericidal Concentration (MBC) and antibiofilm from 70% ethanol extract of Batak onion bulbs against S.mutans and E.faecalis. Material and Methods: This type of research is a laboratory experiment with a post-test only control group design. Determination of MIC by Kirby Baurer disc diffusion method, determination of MBC by streaking method, and colony tests are calculated using colony counters, determination of antibiofilm by Static Microtiter Plate Assays method, and checking the optical density at around 600nm. Data analysis of MIC, MBC, and antibiofilm using Oneway Anova and Post Hoc LSD tests. Results: MIC on S.mutans and E.faecalis was at a concentration of 0.78% with an average of one of inhibition of 9.00 ± 0.43 mm and 8.06 ± 0.20 mm; no MBC was found because no group was able to reduce bacteria 98-98%, Batak onion bulb extract has antibiofilm ability starting at a concentration of 0.78% with the ability to reduce S.mutans bacteria by 84.55% and 85.73% on E.faecalis. Conclusion: 70% ethanol extract of Batak onion bulbs can inhibit bacterial growth and biofilm of S.mutans and E.faecalis. The recommended dose for antibacterial and antibiofilm is a 6.25-50% concentration. https://biomedpharmajournal.org/vol17no1/antibacterial-and-antibiofilm-activity-of-ethanol-extract-of-batak-onion-bulbs-allium-chinense-g-don-against-streptococcus-mutans-and-enterococcus-faecalis/ Antibacterial Antibiofilm Batak onion bulb E.faecalis S.mutans