Torsional fatigue resistance of R‐Pilot and WaveOne Gold Glider NiTi glide‐path reciprocating systems

Abstract

Aim

To evaluate the torsional properties of the NiTi glide‐path reciprocating instruments R‐Pilot (VDW, Munich, Germany) and WaveOne Gold Glider (Dentsply Sirona, Ballaigues, Switzerland).

Methodology

Ten R‐Pilot (size 12.5, .04 taper) and ten WaveOne Gold Glider (size 15, .02v taper) instruments were used. The torque and angle of rotation at failure of new instruments (n = 10) were measured according to ISO 3630‐1. Three millimetres of each instrument tip was clamped to a small load cell by a lever arm linked to the torsion axis. The fracture surface of all fragments was examined with a scanning electron microscope. Data were analyzed using the Student t‐test at a significance level of P < .05.

Results

The maximum torsional strength of the R‐Pilot instruments was greater than the WaveOne Gold Glider (P<0.05). In contrast, WaveOne Gold Glider instruments had significantly higher angular rotation to fracture than R‐Pilot instruments (P<0.05). The scanning electron microscopy of the fracture surfaces revealed similar and typical features of torsional failure (ductile type) for both brands. The torsional failure displayed 2 zones: the first with microvoids in the centre of the instruments (core) and the second one represented by plastic deformation around the microvoids; this configuration occurred because of the shear stresses originated during the twisting.

Conclusions

R‐Pilot instruments had a lower angle of rotation to fracture but a higher torque to failure than WaveOne Gold Glider instruments.

This article is protected by copyright. All rights reserved.

http://bit.ly/2VbPdVd