Abstract

The purpose of this study was to compare the antimicrobial efficacy of sodium hypochlorite (NaOCl) and different natural essential oils for root canal irrigation using two activity tests (contact and diffusion agar tests). Thirty-seven extracted human teeth were collected and incubated with Staphylococcus aureus for 48 h. The teeth were divided into three divisions’ experimental groups, negative control and one positive control group. The canals were instrumented and irrigated with both 5.25 and 2.5% NaOCl as positive control and with essential oils as experimental groups. Bacterial samples were collected after instrumentation/irrigation and after additional canal enlargement. The data showed that essential oils were very effective for disinfection of S. aureus in root canals of patient's teeth in dentistry clinic without significant difference between NaOCl and tested extracts. The statistical analysis of Furthermore, the essential oils were subjected to screening for their possible antioxidant activity by two complementary test system, 2,2´-diphenylpicrylhydrazyl (DPPH) free radical scavenging and 2,2'- azino-bis [ethylbenzthiazoline-6- sulfonic acid] (ABTS) methods. Butylated hydroxyl anisole (BHA) was used as positive control in both systems.  All the tested essential oils showed antioxidant activity against DPPH and ABTS radical more than 50% but less than butylated hydroxyl anisole as synthetic standard.

Key words: Essential oils, root canal irrigation; sodium hypochlorite, antioxidant activity, antimicrobial activity, Staphylococcus aureus.