B Background: root canal infection is one of the major causes of endodontic treatment failure and is commonly associated with anaerobic bacteria, including prevotella intermedia. sodium hypochlorite is the most widely used root canal irrigant due to its excellent antimicrobial properties; however, its use is associated with several limitations, such as cytotoxicity and the potential to cause irritation of the periapical tissues. therefore, an alternative irrigating solution that is effective and more biocompatible is needed. single-clove garlic (allium sativum) extract contains bioactive compounds, particularly allicin, which have demonstrated antibacterial activity against various pathogenic bacteria, including anaerobic bacteria involved in root canal infections. objective: this study aims to determine the antibacterial potential of single-clove garlic (allium sativum) extract against prevotella intermedia as a root canal irrigant by evaluating the bacterial colony count following the application of different extract concentrations. methods: this study is a laboratory experimental study using a post-test only control group design. the samples consist of prevotella intermedia bacterial cultures divided into several groups, including a positive control group, a negative control group, and treatment groups receiving different concentrations of single-clove garlic extract. all samples will be incubated according to the study protocol, followed by bacterial colony count assessment. the collected data will be analyzed using appropriate statistical tests with a significance level of p < 0.05. results: the mean number of bacterial colonies decreased with increasing concentrations of single garlic extract. the 15% concentration exhibited the lowest number of bacterial colonies compared with the 5% and 10% concentrations. the kruskal–wallis test demonstrated a statistically significant difference among the treatment groups. conclusion: single-clove garlic (allium sativum) extract is expected to have the potential to serve as an alternative root canal irrigant with antibacterial activity against prevotella intermedia.