The aim of this study was evaluation the effective of chelating solutions 17% EDTA, 0.2% Chitosan and 10% Sodium citrate by comparing the concentrations of chelated calcium ions after (1min-5min-24h) of application. The study was performed on 45 extracted single-rooted sound human. The sample was randomly divided into groups (n=3), each group 15 teeth that depend on the used solution.