Objective: The aim of this in-vitro study was to determine whether additives could be used with MTA to improve the material’s poor handling characteristics and influence of propylene glycol on the physical properties and marginal adaptation of MTA. Materials and Method: The study was conducted in two parts as follows: Part I: preparation the modified MTA powder samples, characterization, and physical properties of modified MTA. Part II: Marginal adaptation of the prepared experimental materials in root filled extracted permanent teeth as compared to the control was considered. Two transverse sections to represent the adaptation and presence of voids in the apical and middle third of the filled canal were examined by stereomicroscope and SEM. Results: The additions of the sodium chloride reduce the setting time. Increase the pH through all the periods more even than the MTA. Experimental materials showed high solubility than the MTA. Amount of calcium ion decreased as compared to MTA. Proper marginal adaptation to the dentin surface and there was no significant difference between MTASC and MTA; both showed significantly lowest mean void area %. Conclusion: the addition of calcium silicate, calcium hydroxide and propylene glycol to the MTA has an impact on the physical properties of this material.