Debris extrusion and foraminal deformation produced by reciprocating instruments made of thermally treated NiTi wires

Abstract

Objective: To evaluate the amount of apically extruded debris, percentage of foraminal enlargement and apical foramen (AF) deformation that occurred during root canal preparation with different reciprocation systems: Reciproc, WaveOne (M-Wire), and ProDesign R (Shape Memory Technology Wire) at two different working lengths (WLs): 0.0 and 1.0 mm beyond the AF. Material and methods: The AF of 120 root canals in 60 mesial roots of mandibular molars were photographed with stereomicroscope and randomly assigned into four groups: manual, Reciproc (REC), WaveOne (WO), and ProDesign R (PDR); subsequently, they were further subdivided according to the WL (n=15). Teeth were instrumented, coupled to a dual collecting chamber, and then another photograph of each AF was captured. Extrusion was analysed by determining the weight of extruded debris. Each AF diameter was measured in pre-and post-instrumentation images to determine deformation, which was analysed, and afterwards the final format of AFs was classified (circular/oval/deformed). Results: We found no significant differences when analysing each system at different WLs. When considering each WL, REC and WO showed highest extrusion values (P