Aim : This study was designed to prepare an experimental 2% chlorhexidine gel and evaluate its effect on radicular dentin’s microhardness and fracture resistance compared to both calcium hydroxide paste and a mixture of chlorhexidine with calcium hydroxide. Methodology: Experimental 2% chlorhexidine gel was prepared using a poloxamer vehicle. The canals of thirty extracted upper second premolars teeth were prepared and divided equally into five groups (A-E) according to the applied dressing material using : sterile saline (Control Group), Ultracal calcium hydroxide paste, the experimental 2% chlorhexidine gel, the prepared mixture of chlorhexidine with calcium hydroxide and 18% poloxamer vehicle gel respectively. Microhardness and fracture resistance testing were done after three and seven days storage in saline solution. Results: Results revealed that after three days, group C showed the highest Vickers microhardness mean values, while group B recorded the lowest mean values . After seven days group A showed the highest Vickers microhardness mean values , while group B recorded the lowest mean values. After three days group C showed the highest fracture resistance mean values while group E recorded the lowest mean value at cervical sections. At the middle region, group A recorded the highest fracture resistance mean values while group D recorded the lowest mean values. Testing was done at the middle third region of the teeth. Conclusion: The mechanical properties of the root canal dentin decreases with the increase in the application time of the intracanal medicaments. Calcium hydroxide containing medicaments affected the microhardness of the root canal dentin compared to the other tested materials.