往復動経路探索装置による滑走経路：性能と破断率

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

抄録

はじめに:

本研究では、下顎臼歯部の中・遠位管において、R-Pilot往復運動式経路探索装置がマクログライドパス処置中に作業長（WL）に到達した管腔の数を評価した。また、破折率と変形率も評価した。

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.

方法:

52歯156根管を根尖孔の長さまでスカウトした。その後、R-Pilotインスツルメントを根管開口部に配置し、作動させた。器具は、ペッキングモーションと軽い根尖圧を使用して移動させた。この手順を繰り返し、WLに到達させた。破折の種類および/または器具の変形を走査型電子顕微鏡で評価し、破折した器具を装着した根をマイクロCTでスキャンした。破折、変形、および R-Pilot が WL に到達した根管の割合頻度分布を記録し、α=5% の Pearson の χ 検定を用いて統計的に比較した。

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 χ test with α = 5%.

結果:

R-PilotがWLに到達した根管は139本（89.10%）であり、χ検定により、観察された頻度と予想された頻度との間に有意差が認められた（χ=95.41、P=.000）。破折（2.56％）および変形（1.92％）の観察頻度も予想頻度より有意に低かった（破折：χ=140.41、P=.000、変形：χ=144.23、P=.000）。破折は、根管の先端部と湾曲部に多く発生した。

RESULTS: R-Pilot instruments reached the WL in 139 root canals (89.10%), and χ test showed a significant difference between the observed frequencies and the expected frequencies (χ = 95.41, P = .000). The observed frequencies of fractures (2.56%) and deformations (1.92%) were also significantly lower than the expected (fracture: χ = 140.41, P = .000; deformation: χ = 144.23, P = .000). Fractures occurred mostly at the apical and curved parts of the root canals.

結論:

R-Pilotは下顎大臼歯根管の89.10％でWLに到達し，破折率は2.56％，変形率は1.92％であった．

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.