Antibacterial effect of catalytic Iron oxide Nanoparticles, Sodium Hypochlorite, Hydrogen Peroxide and Qmix as a final rinse on Enterococcus faecalis colonizing the dentinal tubules of single rooted teeth (an in vitro study)

Introduction: Bacterial infection is one of the main causes of pulpal and periapical diseases. Presistent infection is a great challenge for dentists. Several newly introduced irrigants, such as catalytic iron oxide and QMix, can help improve the eradication of this infection. Aim: Evaluation of antibacterial effcet of catalytic iron oxide nanoparticles with 3% H ₂ O ₂ , iron oxide nanoparticles, 3% H ₂ O ₂ , QMix, and NaOCl as a final rinse on Enterococcus faecalis colonizing the dentinal tubules of single rooted teeth. Materials and methods: Fifty extracted human permanent single rooted teeth were selected; root canals were prepared using ProTaper Next up to size X4 and irrigated with 3ml of 2.5% NaOCl between each file using a 30-gauge needle in a plastic syringe. Canals were flushed with 5ml of distilled water followed by 5ml of 17% EDTA for 3 minutes then flushed with distilled water again. Final rinse was done with 5ml of: 2.5% NaOCl, QMix, 3%H ₂ O ₂ , IO-NP (0.5 mg/mL) or IO-NP + 3% H ₂ O ₂ for 5 minutes. Each root was split longitudinally into two halves. One representative half was viewed at standard levels: 6 mm and 12 mm from apex representing apical and middle thirds. Samples were stained by using LIVE/DEAD BacLight bacterial viability kit and inspected using CLSM. Results: The comparison between the five irrigant groups revealed that there was a statistically significant difference between all the groups with a p value (<0.001), with the highest value being recorded for IONP + 3% H ₂ O ₂ . Conclusion: IO-NP + 3% H ₂ O ₂ has a higher antibacterial effect in relation to other irrigants.