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Document Type |
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Thesis |
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Document Title |
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Influence of Different Movement Directions of Reciprocation and Continuous Rotation on the Cyclic Fatigue of Nickel-Titanium Endodontic Instruments. تأثير اختلاف اتجاهات الحركة (المعاملة بالمثل والدوران المستمر) على دوري التعب للأدوات اللبية المصنوعة من النيكل تيتانيوم. |
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Subject |
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Faculty of Dentistry |
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Document Language |
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Arabic |
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Abstract |
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Aim of the study
To assess the difference in dynamic cyclic fatigue resistance of rotary systems tested in clockwise and counterclockwise continuous rotation against two different reciprocal motions. To measure the lengths of broken segments of ProTaper Gold files and WaveOne Gold files tested in clockwise and counterclockwise continuous rotation against two different reciprocal motions.
Materials and Methods
A total of 200 files were tested at 300 rpm. These files were divided into four groups according to direction and type of motion: (A) clockwise continuous rotation, (B) counterclockwise continuous rotation, (C) reciprocal motion with 150° counterclockwise and then 30° clockwise rotation, and (D) reciprocal motion with 150° clockwise and then 30° counterclockwise rotation. Each group was subdivided into two subgroups according to the rotary system used: subgroup (1) ProTaper Gold, F1 (Dentsply Maillefer, Ballaigues, Switzerland), and subgroup (2) WaveOne Gold, size 20 and 7% taper (Dentsply Maillefer, Ballaigues, Switzerland). The files were operated in a stainless-steel artificial canal with a 60° angle of curvature and a 5-mm radius. A continuous, axial oscillating motion was applied at one cycle per second. The file cycled 3 mm above and 3 mm below the starting point. The number of cycles to failure (NCF) was recorded. The data were analyzed by using two-way analysis of variance (ANOVA).
Results
No significant difference in NCF was found between Groups A and B, or between Groups C and D in all rotary systems used (p > 0.05). However, reciprocal motions exhibited higher cyclic fatigue resistance than continuous rotations (p < 0.05). Moreover, ProTaper Gold showed higher cyclic fatigue resistance than WaveOne Gold (p < 0.05)
Conclusions
Reciprocal motions have increased cyclic fatigue resistance, but the direction of motion had no effect on the fatigue life of the tested instruments. ProTaper Gold files had higher resistance to cyclic fatigue than WaveOne Gold files. Kinematics had no influence on the length of separated segments. However, ProTaper Golds had longer separated segments than WaveOne Gold due to the differences in their cross-sectional designs. |
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Supervisor |
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Prof. Omar M. Fahim |
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Thesis Type |
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Master Thesis |
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Publishing Year |
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1443 AH
2022 AD |
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Co-Supervisor |
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Dr. Tariq Saad Abuhaimed |
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Added Date |
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Saturday, January 28, 2023 |
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Researchers
| نواف سمير حنبظاظه | Hanbazaza, Nawaf Samir | Researcher | Master | |
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