Comparative Efficacy and Extrusion risk of Polypropylene Needle Versus Various Supplemental Irrigations in Cleaning Simulated Curved Root Canals.

INTRODUCTION This in vitro study compared the cleaning efficacy and irrigant extrusion of polypropylene needles and various supplemental irrigation techniques in curved root canals.

METHODS Simulated canals with 20° (moderate) and 40° (severe) curvatures were prepared to size 25/0.07 and filled with biofilm-mimicking hydrogel. Six irrigation techniques were tested (n = 9 per group): conventional irrigation with stainless steel needles (SN), conventional irrigation with polypropylene needles (PN), and stainless-steel needles supplemented with manual dynamic agitation using a 4% standardized cone (MDA-S), manual dynamic agitation with a matched cone (MDA-M), sonic activation with EDDY, or mechanical activation with XP-endo Finisher (XP). Residual hydrogel in the main canal, hydrogel clearance in accessory canals, and irrigant extrusion through the apical vent were assessed. Data were analyzed using two-way ANOVA with Bonferroni post hoc test (P < .05).

RESULTS In the severe curvature, PN resulted in significantly less residual hydrogel in the main canal than SN (P < .05). However, in both curvatures, all supplemental techniques showed superior performance compared with PN (P < .05). MDA-M provided the greatest hydrogel clearance in main and accessory canals (P < .05), but with the highest extrusion (P < .05).

CONCLUSION Polypropylene needles improved apical cleaning in severely curved canals compared with stainless steel needles. However, supplemental activation provided superior overall debridement in both curvatures, although with an increased risk of extrusion.