Atomic force microscopic analysis of root dentin surface roughness using final irrigation with N-acetyl cysteine, chlorhexidine, and chitosan nanoparticles solutions: An in vitro study

Introduction: A combination of irrigants exerts a synergistic effect during root canal treatment. N-acetyl cysteine (NAC) is used for root canal irrigation. However, its effect on the root dentin surface in combination with chlorhexidine gluconate (CHX) and chitosan nanoparticles (Csnps) is not reported yet. This study aims to evaluate the effect of NAC combined with CHX and Csnps on root dentin surface roughness using an atomic force microscope. Materials and Methods: Thirty single-rooted human extracted mandibular bicuspid teeth were collected, cleaned and decoronated at cementoenamel junction level and sectioned longitudinally in buccolingual direction into two halves to obtain 60 samples which were mounted on acrylic resin blocks and randomly segregated into six groups ( n = 10) and irrigated with 10 ml of following solutions. Group 1 – distilled water (control), Group 2 – 20% NAC, Group 3 – 2% CHX, Group 4-0.2% Csnps, Group 5 – 20% NAC + 2% CHX, and Group 6 – 20% NAC + 0.2% Csnps. The surface roughness (Ra) was determined using atomic force microscopy. Statistical analysis was done by one-way ANOVA and post hoc Tukey tests ( P ≤ 0.05). Results: Surface roughness of root dentin was the least in NAC + Csnps, followed by NAC + CHX. However, individual solutions showed higher surface roughness than combinations ( P ≤ 0.05). Conclusion: Combination of NAC with either Csnps or CHX showed less surface roughness; however, combination with Csnps showed the least surface roughness. Hence, the combination proved to be an effective irrigant regimen rather than using them alone.