Introduction: Irrigation material commonly used for root canal treatment is sodium hypochlorite. The material is reported to have dissolving and antimicrobial properties. However, the material is also reported to have some risk of emphysema, and unpleasant odors. Therefore, a lot of research has been carried out to find efficient irrigant alterna-tives. This study aims to determine the toxicity of apple cider vinegar to fibroblast cells as an alternative root canal irrigation material. Methods: This study uses a descriptive analytic study design. The sample used in this study is hu-man fibroblast cells. The fibroblast cells will be multiplied and then treated with apple vinegar with an exposure time of 10 minutes, 20 minutes, and 30 minutes and with a concentration of 2.5%; 5%; and 10%. Results: In fibroblast cells treated with apple cider vinegar at 10 minutes exposure, the highest number of surviving cells was obtained from the 2.5% group with the T-test which was 0.46. At a time of 20 minutes, the highest number of surviving cells was obtained from the 2.5% group with the T-test which was 0.01. On exposure to 30 minutes, the highest number of surviving cells was obtained from a group of 5% with a T-test which was 0.03. Conclusion: Safe use of apple cider vinegar is at a concentration of 2.5% and 5% at a 10-minute exposure time.