Comparisons of single and multiple file system root canal preperation techniques with different parameters

Aim: The aim of this study was to evaluate the amount of extruded irrigant and debris produced by different rotary systems and to determine the influences of gravitational force and working length changes in curved canals on extrusion. Materials and Methods: One hundred twenty severely curved maxillary and mandibular molar root canals were instrumented with; Twisted File Adaptive, WaveOne, ProTaper Next, Mtwo and One Shape. Each group was divided into two subgroups as maxillary and mandibular according to their location at the experimental set-up. The amount of extruded irrigant and debris were weighed using a 10-5 microbalance. Additionally, working length changes of curved canals were measured before and after root canal instrumentation with stereomicroscop and micrometer. The working time required to complete instrumentation was recorded. Results: The location of tooth and the instrument used had no significant effect on the amount of extrusion (P > 0.05). When the gravitational force via tooth locations was considered irrespective of the instruments, significantly more irrigant and debris were extruded in mandibular location (P < 0.001). A positive correlation was determined between the amount of extruded irrigant and debris (P = 0.001). On the other hand there was no correlation between working length changes and extruded debris (P > 0.05). The TFA extruded significantly less irrigant compared to other groups (P = 0.003). The preparation time with MT was significantly longer than other systems (P < 0.05). Conclusions: All rotary instruments caused irrigant and debris extrusion. Also none of the analysed factors such as instrument technique, gravity and the amount of working length change of curved root canal have an effect on the extruded debris.