| Autor: |
Eugenio Pedullà, Fabio Lo Savio, Gianluca Plotino, Nicola Maria Grande, Silvia Rapisarda, Gianluca Gambarini, Guido La Rosa |
| Jazyk: |
angličtina |
| Rok vydání: |
2015 |
| Předmět: |
|
| Zdroj: |
Giornale Italiano di Endodonzia, Vol 29, Iss 1, Pp 3-8 (2015) |
| Druh dokumentu: |
article |
| ISSN: |
1121-4171 |
| DOI: |
10.1016/j.gien.2015.05.002 |
| Popis: |
Aim: To evaluate the influence of different torsional preloads on cyclic fatigue resistance of endodontic rotary instruments made by conventional nickel–titanium (NiTi) or M-Wire. Methods: Eighty new Mtwo (#25/0.06) (Sweden & Martina, Due Carrare, Padova, Italy) and ProTaper Next X2 (Dentsply Maillefer, Ballaigues, Switzerland) were used. The Torque and distortion angles at failure of new instruments (n = 10) were measured and 0% (n = 10), 25%, 50%, and 75% (n = 20) of the mean ultimate torsional strength as preloading condition were applied according to ISO 3630-1 for each brand. The twenty files tested for every extent of preload were subjected to 25 or 50 torsional cycles (n = 10). After torsional preloading, the number of cycles to failure was evaluated in a simulated canal with 60° angle of curvature and 5 mm of radius of curvature. Data were analyzed using 2-way analysis of variance. Scanning electron microscope (SEM) was performed to evaluate the fracture surface of each fragment. Results: ProTaper Next X2 reduced their cyclic fatigue after 25 or 50 cycles of every torsional preloading (25%, 50%, and 75%) (P |
| Databáze: |
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