Glide Path with Reciprocating Driven Pathfinding Instrument: Performance and Fracture Rate.

INTRODUCTION:This study assessed the number of mesial and distal canals of mandibular molars in which the R-Pilot pathfinding reciprocating instrument reached the working length (WL) during macro glide path procedure. Fracture and deformation rates were also evaluated. METHODS:One hundred fifty-six root canals of 52 teeth were scouted to the length of the apical foramen. Then the R-Pilot instrument was positioned at the canal orifice and activated. The instrument was moved by using a pecking motion and light apical pressure. This procedure was repeated in an attempt to reach the WL. The type of fracture and/or instrument deformation was assessed by scanning electron microscopy, whereas the roots with fractured instruments were scanned through micro-computed tomography. The percentage frequency distribution of fractures, deformations, and root canals in which the R-Pilot reached the WL were recorded and statistically compared by using the Pearson's χ2 test with α = 5%. RESULTS:R-Pilot instruments reached the WL in 139 root canals (89.10%), and χ2 test showed a significant difference between the observed frequencies and the expected frequencies (χ2 = 95.41, P = .000). The observed frequencies of fractures (2.56%) and deformations (1.92%) were also significantly lower than the expected (fracture: χ2 = 140.41, P = .000; deformation: χ2 = 144.23, P = .000). Fractures occurred mostly at the apical and curved parts of the root canals. CONCLUSIONS:R-Pilot reached the WL in 89.10% of the root canals of mandibular molars with fracture and deformation rates of 2.56% and 1.92%, respectively.