Assessment of smear layer removal utilizing a conservative root canal instrumentation technique involving magnetically agitated irrigation with iron paramagnetic nanoparticles

Background : The development of new technology in mechanical instrumentation does not completely clean all the root canal walls because of the disparity between the complexities of canal anatomical and instrument design. This study aimed to determine the optimum effect of iron oxide nanomagnet particles (IONPs) in cleaning the surface of the root canal and open dentin tubules, as well as analyze the dispersion of iron ions on the dentinal walls. Material and methods: Sixty intact extraction teeth were used and divided into six groups as stated by agitation protocol of irrigant: Group 1: Control, Group 2: Normal saline with ultrasound, Group 3: IONP with ultrasound. Group 4: IONP with magnetic field using an endodontic needle. Group 5: IONP with magnetic field using ultrasound, and Group 6: 17% ethylenediaminetetraacetic acid (EDTA). Field emission scan electron microscopy (FE-SEM) and energy-dispersive X-ray spectroscopy (EDS) were utilized to determine cleaning root canal surfaces, opening dentinal tubules, removing the smear layer, and the percentage dispersion of ions on the root canal wall. The nonparametric tests of the Kruskal-Wallis, Mann-Whitney, and parametric test of One-Way ANOVA and Tuckey posthoc tests were used to compare irrigation protocols. Results : Compared to the other groups, the agitation of irrigant IONP using a combination of a magnetic field and an ultrasound device proved to be the most effective. Additionally, the agitation of irrigant IONP using only an ultrasound device was more effective than using only normal saline with an ultrasound device. Iron ions have low percentages, perfect dispersions, and minimal precipitation in the apical section of the root canal wall. Conclusion: Compared to the control group, the utilization of IONP irrigant agitation with a magnetic field did not affect dentinal structure while enhancing the cleaning of the canal surface, opening dentin tubules, and achieving a uniform distribution of iron ions with minimal precipitation. These findings may hold promise as a tool for endodontic treatment while preserving tooth structure.