Caries is caused by microbial activity of a fermented carbohydrate. Preventive efforts gargling mouthwash contains antibacterial, long-term use has side effects, so we need herbal ingredients that have antibacterial properties, one of which is celery leaves. This study aims to prove the potential of celery leaf extract (Apium graveolens L.) as a mouthwash ingredient in reducing the number of bacterial colonies compared to formulary controls without active ingredients. This type of research used laboratory and field experiments with pretest-posttest consisting of the intervention group of celery leaf extract mouthwash formulation concentrations of 30%, 15% and control formulary without active ingredients, the sample consisted of 39 people, the sample was rinsed for 1 minute. Saliva collection before and after gargling. The variable studied was the number of bacterial colonies. The results of the Paired t-test for the number of bacterial colonies at a concentration of 15% showed a Δ -105.846 p-value of 0.025 meaning that there were differences in bacterial colonies before and after rinsing, a 30% concentration had a Δ value of 17.846 pvalue 0.351 and a control value of 7.385 p-value 0.183 meaning that there is no significant difference but there is a decrease in the number of bacterial colonies. The conclusion of this study is that giving celery leaf extract mouthwash with a concentration of 30% for 1 minute is effective in reducing the number of bacterial colonies compared to formularies without active ingredients. 183 means there is no significant difference but there is a decrease in the number of bacterial colonies. The conclusion of this study is that giving celery leaf extract mouthwash with a concentration of 30% for 1 minute is effective in reducing the number of bacterial colonies compared to formularies without active ingredients. 183 means there is no significant difference but there is a decrease in the number of bacterial colonies. The conclusion of this study is that giving celery leaf extract mouthwash with a concentration of 30% for 1 minute is effective in reducing the number of bacterial colonies compared to formularies without active ingredients.

Keywords : Antibacterial, Celery Leaf Extract, Bacteria that Cause Dental Caries.