comparison of apical extrusion of debris by using single-file, full-sequence rotary and reciprocating systems

Objectives: during root canal preparation, apical extrusion of debris can cause inflammation, flare-ups, and delayed healing. therefore, instrumentation techniques that cause the least extrusion of debris are desirable. this study aimed to compare apical extrusion of debris by five single-file, full-sequence rotary and reciprocating systems. materials and methods: one hundred twenty human mandibular premolars with similar root lengths, apical diameters, and canal curvatures were selected and randomly assigned to six groups (n=20): reciproc r25 (25, 0.08), waveone primary (25, 0.08), oneshape (25, 0.06), f360 (25, 0.04), neoniti a1 (25, 0.08), and protaper universal. instrumentation of the root canals was performed in accordance with the manufacturers’ instructions. each tooth's debris was collected in a pre-weighed vial. after drying the debris in an incubator, the mass was measured three times consecutively; the mean was then calculated. the preparation time by each system was also measured. for data analysis, one-way anova and games-howell post hoc test were used. results: the mean masses (±standard deviation) of the apical debris were as follows: 2.071±1.38mg (protaper universal), 1.702±1.306mg (neoniti a1), 1.295±0.839mg (oneshape), 1.109±0.676mg (waveone), 0.976±0.478mg (reciproc) and 0.797±0.531mg (f360). compared to protaper universal, f360 generated significantly less debris (p=0.02). the protaper system required the longest preparation time (mean=88.6 seconds); the reciproc (p=0.008), oneshape (p=0.006), and f360 (p=0.001) required significantly less time (p<0.05). conclusions: all instruments caused extrusion of debris through the apex. the f360 produced significantly less debris than did the protaper universal.