Zoya A, et al. - Researchers assessed 60 mandibular single-rooted premolars with intact CEJ to estimate the extraradicular peroxide release from sodium percarbonate vs sodium perborate as an intracoronal bleaching agent. They noted the descending sequence of peroxide release: hydrogen peroxide as positive control (HP) group, followed by the sodium percarbonate with 30% hydrogen peroxide (SPCHP) and sodium perborate with 30% hydrogen peroxide (SPHP) groups, and then, sodium percarbonate with distilled water (SPCW) and sodium perborate with distilled water (SPW) groups. They observed no significant variation in peroxide release between the groups SPCW and SPW on days 1, 3 and 6. They also noted no differences between the SPCHP and SPHP treated groups on days 1, 3 and 6. Overall, they suggested a similarity between extraradicular peroxide release from sodium percarbonate and sodium perborate.