Comparative Evaluation of Antimicrobial Efficacy, Depth of Penetration into Dentinal Tubules and Effect on Microhardness of Root Dentin by Sodium Hypochlorite, Neem Extract and Gau Ark as Root Canal Irrigants: An In-vitro Study

Introduction: Disinfection of root canals can be done using intracanal irrigants. Sodium hypochlorite or NaOCL is amongst the most commonly used endodontic irrigants. Due to disadvantages of NaOCl, there is a need to identify a more biocompatible irrigant. Aim: To evaluate the antibacterial efficacy, depth of penetration into dentinal tubules and effect on microhardness of root dentin when NaOCl, Neem extract, Gau ark and Normal saline used as an irrigant against Enterococcus faecalis. Materials and Methods: Prepared Neem leaf extract, 3% NaOCl, Gau ark, Normal saline, Brain Heart Infusion (BHI) broth and BHI Agar were used in the present in-vitro study conducted from August-October 2019. Antimicrobial efficacy was measured by agar well diffusion method on 10 petriplates. After access opening and biomechanical preparation, each tooth sample was irrigated with 5 mL of irrigant. Samples were decoronated and roots were split along the longitudinal axis to check penetration depth of irrigants under stereomicroscope for 40 teeth samples. After preparation of 40 teeth sample, 2 mm dentin discs prepared were embedded in acrylic resin. Microhardness was checked under Vickers Microhardness (VHN) tester after samples were irrigated. Statistical Analysis of Variance and Tukey post-hoc test were used. Results: Zones of inhibition were highest with NaOCl (7.66 mm). Irrigants penetration depth into dentinal tubules was significant with NaOCl with average value 0.35 mm. Microhardness of root dentin of saline was 145.90 VHN, followed by Neem 136.59 VHN which was then followed by Gau ark 123.05 VHN hence, Neem has lesser effect on microhardness value as compared to NaOCl and Gau ark. There was statistically significant difference among four groups regarding antimicrobial efficacy, depth of penetration into dentinal tubules and microhardness of root dentin. Conclusion: Neem extract showed significant antimicrobial property as compared to Gau ark and normal saline, good penetration depth and less effect on microhardness of root dentin. Herbal irrigant like Neem extract can be used as a root canal irrigant.