Effectiveness of Various Endodontic Irrigants on the Micro-Hardness of the Root Canal Dentin: An in vitro Study

Irrigating solutions used for the elimination of micro-organisms during root canal preparation may affect the chemical and the physical properties of dentin thereby rendering the tooth more susceptible to fracture. Therefore careful and judicious selection of irrigant is required which have maximum benefits with minimum undesirable properties.

The aim of the present study was to evaluate the effect of various endodontic irrigants on the micro-hardness of the root canal dentin.

This in vitro study was carried out on eighty freshly extracted mandibular premolars with single canals. They were decoronated at the cemento-enamel junction. Roots were sectioned longitudinally into two halves. They were then polished and placed in autopolymerised resin moulds with the polished surface facing outside. The samples were divided into four groups based on the irrigants in which they were immersed i.e., 3% Sodium Hypochlorite (3% NaOCl), 17% Ethylene Dioxide Tetra Acetic Acid (17% EDTA), 0.2% Chitosan and 6% Morindacitrifolia Juice (MCJ) for 15 minutes each. All the specimens were then subjected to micro-hardness testing using a Vickers micro-hardness tester. Statistical analysis was done using one way Analysis of Variance (ANOVA), Post-Hoc Tukey test and Paired t-test to compare the pre and post immersion micro-hardness values of the selected samples.

The results of the present study indicated that 17% EDTA and 0.2% Chitosan, significantly decreased the micro-hardness of root dentin whereas 6% MCJ and 3% NaOCl had no significant effect on the microhardness before and after immersing in the irrigants.

A 6% MCJ and 3% NaOCl which have significant antibacterial, antifungal, anti-inflammatory and smear layer removing properties showed negligible effect on the micro-hardness of root canal dentin making them suitable endodontic irrigating solution.