The purpose of the present study was to evaluate the effect of manual dynamic activation (MDA) with a master gutta-percha point on the smear layer removal efficacy of 17% ethylenediaminetetraacetic acid (EDTA) and SmearClear. Fifty freshly extracted human single-rooted teeth were prepared using ProTaper rotary system up to F3 size. The prepared teeth were divided into five groups on the basis of final irrigation received. Group A: 3% NaOCl solution (negative control group). Group B: 5 mL of 17% EDTA. Group C: 1 mL of 17% EDTA + MDA for 2 min + 4 mL of 17% EDTA rinse. Group D: 5 mL of SmearClear. Group E: 1 mL of SmearClear + MDA for 2 min + 4 mL of SmearClear rinse. Prepared samples were decoronated and then longitudinally split into two halves and evaluated under scanning electron microscope. Representative images at coronal, middle and apical third level were taken and scored for the amount of smear layer present, using a three-score system. The data were analysed through Kruskal-Wallis and Mann-Whitney U-test. The root canal surfaces of samples of group C and group E (where MDA was done) were significantly cleaner in apical third regions than those of group B and group D (P < 0.05).

Aim To evaluate the extraradicular peroxide release from sodium percarbonate compared to sodium perborate as an intracoronal bleaching agent. Methodology Sixty mandibular single‐rooted premolars with intact CEJ were selected. After root filling, gutta‐percha was removed 4 mm apical to CEJ and 2 mm of GIC was condensed over the root filling. Intracoronal bleaching agents were placed into six groups of teeth (n = 10): sodium perborate with distilled water (SPW); sodium percarbonate with distilled water (SPCW); sodium perborate with 30% hydrogen peroxide (SPHP); sodium percarbonate with 30% hydrogen peroxide (SPCHP); 30% hydrogen peroxide as positive control (HP) and distilled water as negative control (CL). The teeth were then mounted in vials filled with distilled water, kept in an incubator and taken out at 1, 3 and 6 days for spectrophotometric analysis. Extraradicular peroxide release was quantified by the ferrothiocyanate method. Statistical analysis was undertaken with one‐way anova and Scheffe post hoc tests. Results The greatest peroxide release occurred in the HP group, followed by the SPCHP and SPHP groups, and then by the SPCW and SPW groups. Intergroup comparison revealed that there was no significant difference in peroxide release among the groups SPCW and SPW on days 1, 3 and 6 (P > 0.05). Similarly, no significant difference was found between the SPCHP and SPHP treated groups on days 1, 3 and 6 (P > 0.05). Conclusion Extraradicular peroxide release from sodium percarbonate was comparable to that of sodium perborate, as the differences were not significant.