OBJECTIVE: Currently none of the irrigants used in endodontic therapy tested so far either alone or in combination could satisfy all criteria of ideal irrigant. Search for such a single agent which is more biocompatible along with other properties of irrigant continues. This study is aimed to evaluate pulp dissolution, antimicrobial activity, smear layer removing ability, and change in the Ca/P ratio of root dentin by using experimental formulation combining 3 % & 5 % Sodium hypochlorite with 40% Salvadora Persica & comparing it with 3 % Sodium Hypochlorite & 17%EDTA Materials and Methods: Pulp dissolution: Human pulp tissue weighing 0.9g was dissolved in each experimental group G1:3%NaOCl,G2:3%NaOCl+40% S.persica, G3: 5%NaOCl +40% S.persica and weighed after the passage time of 10 min , 20min , 30 min. The difference in weight of the tissue sample before and after exposure to the test solution was assessed. Antibacterial activity: Antimicrobial efficacy of 3% NaOCl, 3% NaOCl + 40% S.Persica,5%NaOCl + 40% S.persica as experimental group against E.fecalis was assessed using direct contact test. Statistical Analysis for both the test was carried out using Kruskal Wallis and Post Hoc Mann Whitney Analysis Smear layer removal& Ca/p ratio analysis: Single rooted premolars were divided in 3 groups (n=33) and irrigated with G1: 17% EDTA , 3% NaOCl, G2 : 3% NaOCl+ 40% S. persica, G3: 5% NaOCl + 40% S.persica. Each tooth was then split longitudinally. One half of sample from each group were subjected to scanning electron microscope to assess smear layer removal and second half for EDX analysis to check Ca/P ratio. Statistical Analysis: SEM – Kruskal Wallis and Post Hoc Mann Whitney EDX – ANOVA and Tukey’S HSD Post hoc Analysis RESULTS: • Pulp dissolution by freshly mixed G3 was superior to G1 & G2. There is no difference in pulp dissolution efficacy of G1 & G2. • No statistically significant difference was seen with respect to smear layer removal among the groups tested. EDX analysis showed significantly low Ca/P ratio for G1 compared to other groups and no statistically significant difference was seen b/w G2 &G3 • In both the time interval tested (5 min, 10min) G3 showed maximum antimicrobial efficacy followed by G1 and G2 in terms of mean value. CONCLUSION: The combined formulation of 5% NaOCl + 40 % S.Persica was most effective root canal irrigant among the groups tested in terms of pulp dissolution, antimicrobial &chelating action. 3% NaOCl + 40% Salvador persica was found to be as effective as 3% NaOCl and 17% EDTA. Experimental irrigants were found to be less erosive to root dentin in both combinations tested.