Cyclic Fatigue Of Two Different Rotary Nickel Titanium Instruments Used In Reciprocation Motion
Mohamed Salah Abd- Elsalam Abd-Elaziz;
Abstract
The purpose of the present study was to evaluate the cyclic fatigueof two different rotary nickel titanium files (protaper F2, wave one) in reciprocation motion.
Thirty two rotary files were used in this study. They were classified into the following groups: Group A:Wave One primary Ni-Ti files ,has the tip ISO size 25,(16 files). Group B: Protaper F2 Ni-Ti files, has the tip ISO size 25, (16files). Then each group was further sub divided into two equal sub- groups according to the tested radii and root canal curvature into:
Sub group 1: 2mm radius of curvature and 600 angle of curvature.
Sub group 2: 5mm radius of curvature and 600 angle of curvature.
A custom made stainless steel cyclic fatigue apparatus was especially designed for this study and a specially fabricated metal block made of stainless steel was used in this test.
The metal block contains four artificial canals 2mm in depth were designed to accommodate each instrument in terms of size and taper , thus providing the instrument with a suitable trajectory ,two of them following geometry of WaveOne and the rest of them following geometry of Protaper F2.
For each system ,one of the two canal has 2mm Radius of curvature and the other 5mm radius of curvature with 60 angle of curvature for all the canals .
The instruments were activated using the preset programme “WaveOne All” mode. All instruments were rotated until fracture occurred and the time to fracture was recorded . Means and standard deviations of time to fracture were calculated for each system and data were subjected to 2 way anova (p <0.05).
A statistically significant difference (p<0.005) was noted between WaveOne and Protaper F2 instruments . WaveOne instruments were associated with a significant increase in the mean time to fracture when compared with Protaper F2 instruments in both radii of curvature (2.38 vs 0.906 s). Examination of the broken files by scanning electron microscope showed similar and typical features of cyclic fatigue for the two brand. Crack initiation area, overload fast fracture zone for cyclic fatigue fractures, concentric abrasion marks and the fibrous dimple marks at the center of rotation.
Conclusions
1)- Cyclic fatigue resistance of files fabricated from M-wire is higher than those fabricated from super elastic NiTi wire.
2)- The decrease in radius of curvature increases cyclic fatigue of files used in reciprocation motion.
Thirty two rotary files were used in this study. They were classified into the following groups: Group A:Wave One primary Ni-Ti files ,has the tip ISO size 25,(16 files). Group B: Protaper F2 Ni-Ti files, has the tip ISO size 25, (16files). Then each group was further sub divided into two equal sub- groups according to the tested radii and root canal curvature into:
Sub group 1: 2mm radius of curvature and 600 angle of curvature.
Sub group 2: 5mm radius of curvature and 600 angle of curvature.
A custom made stainless steel cyclic fatigue apparatus was especially designed for this study and a specially fabricated metal block made of stainless steel was used in this test.
The metal block contains four artificial canals 2mm in depth were designed to accommodate each instrument in terms of size and taper , thus providing the instrument with a suitable trajectory ,two of them following geometry of WaveOne and the rest of them following geometry of Protaper F2.
For each system ,one of the two canal has 2mm Radius of curvature and the other 5mm radius of curvature with 60 angle of curvature for all the canals .
The instruments were activated using the preset programme “WaveOne All” mode. All instruments were rotated until fracture occurred and the time to fracture was recorded . Means and standard deviations of time to fracture were calculated for each system and data were subjected to 2 way anova (p <0.05).
A statistically significant difference (p<0.005) was noted between WaveOne and Protaper F2 instruments . WaveOne instruments were associated with a significant increase in the mean time to fracture when compared with Protaper F2 instruments in both radii of curvature (2.38 vs 0.906 s). Examination of the broken files by scanning electron microscope showed similar and typical features of cyclic fatigue for the two brand. Crack initiation area, overload fast fracture zone for cyclic fatigue fractures, concentric abrasion marks and the fibrous dimple marks at the center of rotation.
Conclusions
1)- Cyclic fatigue resistance of files fabricated from M-wire is higher than those fabricated from super elastic NiTi wire.
2)- The decrease in radius of curvature increases cyclic fatigue of files used in reciprocation motion.
Other data
| Title | Cyclic Fatigue Of Two Different Rotary Nickel Titanium Instruments Used In Reciprocation Motion | Other Titles | المقاومة للمجهود الدورى لالتين مختلفتين من النيكل تيتانيوم المستخدمه فى الدوران المتبادل | Authors | Mohamed Salah Abd- Elsalam Abd-Elaziz | Issue Date | 2015 |
Recommend this item
Similar Items from Core Recommender Database
Items in Ain Shams Scholar are protected by copyright, with all rights reserved, unless otherwise indicated.