Ex vivo accuracy of three electronic apex locators under various irrigants

Evidence on the X-Smart Pro + for apical constriction detection under different irrigants remains limited. This ex vivo study compared X-Smart Pro+, Root ZX Mini, and Propex Pixi in 36 extracted single-rooted teeth standardized to 17 mm. Real working length (RWL) was determined microscopically, and electronic measurements were obtained in an alginate model under saline, 2.5% sodium hypochlorite, 17% EDTA, and 2% chlorhexidine. X-Smart Pro+ was assessed at two distinct points, corresponding to the 4th and 7th green LEDs (GL4 and GL7). Mean deviations from the RWL ranged from - 0.36 to 0.40 mm, and all devices yielded mean measurements within ± 0.5 mm. Root ZX Mini showed the highest overall accuracy by the ± 0.5 mm criterion, whereas X-Smart Pro+ GL4 showed a smaller mean deviation in saline and significantly improved accuracy in 17% EDTA (P < 0.05). GL4 measurements were generally closer to the RWL than GL7, except in NaOCl. Irrigant type did not significantly affect most measurements (P > 0.05). Within the limitations of this ex vivo model, the tested electronic apex locators showed broadly comparable accuracy, and for X-Smart Pro+, GL4 measurements were generally closer to the RWL than GL7.