Objectives: The aim of the study was to compare the antibacterial efficacy and the effect on dentin microhardness of turmeric extract, thymus vulgaris oil, sodium hypochlorite and chlorhexidine when used as root canal irrigants.
Material and methods: Sixty four permanent mandibular single rooted premolars were classified into 4 groups of 16 teeth each according to the final irrigant used. For the antibacterial test, 11 teeth per group (n=11), and the microhardness test, 5 specimens per group (n=5): Group I: 2% Turmeric extract. Group II: 2% Thymus vulgaris oil. Group III: 5.25% NaOCl. Group IV: 2% CHX. Forty four Samples were inoculated with E. faecalis, incubated then chemo-mechanically prepared according to the assigned group, sampled and incubated for 24 hours then Colony Forming Units were counted. Twenty samples were used to create dentin blocks, then were kept in airtight containers saturated with 5 ml of each irrigant for 5 minutes. Microhardness test was performed at different time intervals; After 24 hours, 3 days and 7 days using Vickers hardness indentation machine.
Results: The highest antibacterial efficacy against E. faecalis was in 2% CHX followed by 5.25% NaOCl, 2% Thymus vulgaris oil and finally 2% Turmeric extract. In microhardness test 2% CHX showed the highest statistically significant value of dentin microhardness, followed by 2% Turmeric extract, 2% Thymus and finally 5.25% NaOCl.
Conclusion: Herbals may serve as alternatives to conventional root canal irrigants as they possess antibacterial properties and cause minimal alteration in dentin microhardness when compared to chemical irrigants.