AimTo assess and compare the amount of extruded debris after canal preparation using ProTaper Universal and ProTaper Next files.,MethodologyForty extracted mandibular premolars with single canals and of similar lengths were instrumented using the ProTaper Universal F3 or the ProTaper Next X3. The extruded debris during instrumentation was collected into pre-weighed Eppendorf tubes. The tubes were stored in an incubator for 5days. The tubes were weighed to obtain the final dry weight of the extruded debris. The amount of apically extruded debris was calculated by subtracting the initial weight of the tube from the final weight. The distribution of the data was examined using the Shapiro-Wilks test. Continuous variables were compared with an independent-samples t-test for two groups.,ResultsAll specimens were associated with apical debris extrusion. The ProTaper Universal group produced a significantly greater amount of debris extrusion (P<0.001). The lowest and highest amounts of debris for PTU and PTN groups were recorded as 0.00117-0.00165g and 0.00017-0.00067g, respectively.,ConclusionProTaper Next files was associated with significantly less extruded apical debris when compared to ProTaper Universal files.