RESUMO
OBJECTIVE: The present study aims to assess the quantity of calcium cation eliminated from the root canal by 0.2% chitosan nanoparticles (CNPs) (Sigma Aldrich, Mumbai, Maharashtra, India) and 17% ethylenediaminetetraacetic acid (EDTA) (Pyrax 17% EDTA Solution, Pyrax Polymars, Roorkee, Haridwar, Uttarakhand, India) which are activated with an erbium-doped yttrium aluminum garnet (Er:YAG) laser (LiteTouch™, Light Instruments Ltd., Yokneam Elite, Israel) for smear layer removal using a flame atomic absorption spectrophotometer (AASF) (Deeksha Analytical Pvt Ltd, Gokula Extension, Bengaluru, Karnataka, India). METHODOLOGY: Using the crown-down technique, 60 non-carious single-rooted premolars were instrumented with rotary files and irrigated with 3% sodium hypochlorite. Based on the type of irrigation activation used, all the specimens were arbitrarily divided into five groups with 12 teeth in each group, as follows: G1, 17% EDTA activated with Er:YAG laser; G2, 17% EDTA without laser activation; G3, 0.2% CNP activated with Er:YAG laser; G4, 0.2% CNP without laser activation; and G5, controlled-deionized water. The AASF analysis for the removal of calcium ions in the irrigants was evaluated by collecting the overall quantity of each irrigating solution from the root canals. A one-way analysis of variance (ANOVA) and a Tukey post hoc test were done to determine the AASF data. RESULTS: 17% EDTA activated with Er:YAG laser (130.18 ± 10.3) and 0.2% CNP activated with Er:YAG laser (121.13 ± 3.9) showed the greatest concentration of calcium ions with no statistically significant difference. The lowest concentration of calcium ions was observed in 0.2% CNPs without laser activation (118.64 ± 2.9), while 17% EDTA (125.50 ± 3.0) without laser activation showed an intermediate outcome. The control group did not remove any calcium ions. CONCLUSION: The findings in the present study suggest that EDTA and CNPs, which were activated with lasers, yielded the greatest release of calcium ions equally. Hence, laser-activated CNPs can be employed for essential smear layer removal.