In Vitro Comparison of the Effects of Garlic Juice and Chlorhexidine Mouthwash on Oral Pathogens

Background: Mouthwash is used to complete the process of mechanical plaque removal. Chlorhexidine is the most common ingredient in mouthwash so we can use it as a gold standard to compare the effects of new products. Garlic is a strong antimicrobial agent and acts as an inhibitor on both Gram-positive and Gram-negative bacteria. Objectives: The present study was conducted to compare the effect that garlic juice and Chlorhexidine mouthwash has on oral pathogens. Materials and Methods: Fresh garlic bulbs were used to extract the antibacterial juice. The yellow juice was separated from the pulp with Whatman filter paper. After filtration the liquid was freeze dried and stored at 4°C until required. The bacteria that were tested were: Streptococcus mutans, S. sanguis, S. salivarius and Lactobacillus casei. After cultivation of the bacteria, the Minimal Inhibitory Concentration (MIC) of the garlic juice and Chlorhexidine were measured using the E-test method, then the Minimal Bactericidal Concentration (MBC) of the Chlorhexidine and garlic juice were measured by tube test. Results: The lowest MIC of garlic juice was for S. mutans 0.25 μg/mL and the highest was for L. casei 2. 5μg/mL. The MIC of Chlorhexidine for these two bacteria was 0.62 μg/mL and 5 μg/mL respectively. The MBC of Chlorhexidine and garlic for S. mutans had the lowest concentration compared with the other tested bacteria. The MBC of Chlorhexidine and garlic for S. mutans was 0.35μg/mL and 0.3 μg/mL respectively. The highest MBC of Chlorhexidine was for S. salivarius 10μg/mL. The MBC of garlic for S. sanguis was similar at 10. 4 μg/mL. Conclusions: The efficacy of garlic juice was higher than Chlorhexidine against target bacteria and could be used as an effective mouthwash, but its side effects need to be investigated.