PSI - Issue 2_B

Lo Savio F. et al. / Procedia Structural Integrity 2 (2016) 1311–1318 Lo Savio et al./ Structural Integrity Procedia 00 (2016) 000–000

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size #25, 0.08 taper and size #25, 0.06 taper are presented in Table 1 and Table 2 respectively. Different superscript letters indicate statistic differences among groups (P < .05). Different superscript letters indicate statistic differences among groups (P < .05).

2

2

Torque [N*cm]

Torque [N*cm]

1,5

1,5

1

1

0,5

0,5

Angle [deg]

Angle [deg]

0

0

0 100 200 300 400 500 600

0

50 100 150 200 250

Figure 1. Torque vs. rotation curves for instruments with tip size 25 and 0.08 taper. Left: WaveOne Primary; right: Hyflex EDM OneFile.

2

Torque [N*cm]

1,5

1

0,5

Angle [deg]

0

0

200

400

600

2

Torque [N*cm]

1,5

Figure 2. Torque vs. rotation curve for each brand of tip size 25, 0.06 taper files. Top: left: F6 SkyTaper; right: ProTaper Next. Bottom: Hyflex CM.

1

0,5

Angle [deg]

0

0

100 200 300 400 500

Typical torque/angular rotation curves for torsional fracture for instrument size #25, 0.08 taper and size #25, 0.06 taper are presented in Figure 1 and Figure 2 respectively. Between instrument size #25, 0.08 taper, HEDMOneFile (CM-wire) showed higher angular rotation (P < 0.0001), but lower maximum torsional strength to fracture (P < 0.05) than WO Primary (M-wire). In the same way, comparing instruments size #25, 0.06 taper, Hyflex CM (CM-wire) showed higher angular rotation (P < 0.0001), but lower maximum torsional strength to fracture (P < 0.05) than ProTaper Next X2 (M-wire). F6 SkyTaper (conventional NiTi) showed same torque load and angular rotation to fracture than Hyflex CM (CM