The Influence of Cervical Preflaring on the Amount of Apically Extruded Debris after Root Canal Preparation Using Different Instrumentation Systems

• The apical debris extrusion occurred independent of the instrument used.
• Full-sequence rotary systems promote significant less apical extrusion of debris than reciprocating systems.
• The cervical preflaring was associated to a lesser amount of apical debris extrusion.

IntroductionThe objective of this study was to evaluate the influence of cervical preflaring on the amount of apically extruded debris after root canal preparation using different instrumentation systems.MethodsOne hundred eighty human maxillary central incisors were selected and randomly divided into 12 groups (n = 15). Root canals were instrumented according to manufacturers' instructions using 2 reciprocating single-file systems (Reciproc [VDW, Munich, Germany] and WaveOne [Dentsply Maillefer, Ballaigues, Switzerland]), 3 full-sequence rotary systems (ProTaper Universal [Dentsply Maillefer], ProTaper Next [Dentsply Tulsa Dental, Tulsa, OK], and ProFile [Dentsply Maillefer]), and K-files (Dentsply Maillefer) driven by an oscillatory system with and without cervical preflaring. Bidistilled water was used as irrigant. Apically extruded debris was collected in preweighed glass vials using the Myers and Montgomery method. After drying, the mean weight of debris was determined using a microbalance. Kolmogorov-Smirnov and Levene tests followed by the Tukey post hoc test were used for statistical analysis.ResultsK-files produced significantly more debris than all of the other systems (P < .05). For all systems, cervical preflaring reduced the amount of apically extruded debris when compared with no cervical preflaring (P < .05).ConclusionsAll of the systems extruded debris, irrespective of the preparation technique used (with or without cervical preflaring). Cervical preflaring was associated with the extrusion of smaller quantities of apical debris.