Caspian Journal of Dental Research

Introduction: Tooth decay is a serious oral health problem and occur in a specific area when the lactobacilli of that region reach 8% of the total bacterial population in that area.

Materials & Methods: This experimental-laboratory study was performed on 6 standard groups of bacteria, including a group of 0.2% chlorhexidine and 4 groups of concentrations including 10, 25, 50 and 100 mg / ml of pomegranate peel extract, as well as a blank plate to determine the growth inhibition zone and a one set of standard bacterial samples was performed to determine the MIC on Lactobacillus acidophilus. The obtained data were statistically analyzed by SPSS ver: 26 software, One way ANOVA and Tukey HSD test was used to compare the growth inhibition zone. The mean MIC was also presented with standard deviation and calculation of coefficient of variation.

Results: The inhibition test’s overall results showed that different concentrations of the extract (10,25,50,100 mg/ml) have a positive inhibitory activity against Lactobacillus acidophilus. The general results of inhibitory zone diameter by disk plate method showed that with increasing the concentration of the extract, the amount of antimicrobial effect on bacteria increases and a significant difference was shown between the diameter of the inhibition zone (16.5, 23.5, 26, 29.8 mm) of four concentrations (p value<0.001). In MIC study, the results indicated that the effective amount of hydroalcoholic pomegranate peel extract is in the range between 12.5 to 25 (mg / ml). However, in all the studied groups, CHX had the highest inhibitory effect(30mm).

Conclusion: According to the results of this study, with the increase of pomegranate extract’s concentration, its antimicrobial effect increases as well. Therefore, it seems that Pomegranate peel extract can be used for antimicrobial purposes in mouthwash, toothpaste, gels, candies and chewing gum.