Background: Irrigation is an important step in cleaning the root canal complex, eradicating resistant bacterial biofilm, and removing toxins from the root dentin. Keeping the root canal clean comes at the expense of changing the physical and mechanical properties of the dentinal microstructure.
Aim of the study: This study aims to test the efficacy of newly introduced nano particles irrigations along with the golden standard irrigation regarding their antibacterial effect and the altering of dentin composition within the root canal dentin.
Materials and methods: A total of sixty five single rooted human teeth was accessed and prepared using one shape rotary files to a size of 50#. The teeth were then divided into: antibacterial test group (45 teeth) and dentin composition test group (20 teeth).
Results: Regarding the antibacterial effect, among the study groups: Chitosan (nano particles) recorded the highest mean value followed by Silver (nano particles) the least mean value was recorded in sodium hypochlorite with no significant difference between these 3 groups. Regarding the dentin composition effect: The calcium to phosphorous ratio among root levels apical and middle showed no significant difference among the study groups; But they all exhibited a higher Ca:P ratio to the control group which was statistcally significant.
Conclusion: Silver Nano particles irrigation and Chitosan Nano particles irrigation showed lower antibacterial effects against E. faecalis biofilm than sodium hypochlorite . Similar effect on dentin composition was noticed among the three irrigants used.