Comparison between Three Rotary Nickel Titanium Systems with different Microstructure
Tarek Moustafa Abdel Aziz;
Abstract
Root canal cleaning and shaping are important phases in endodontic therapy. The objectives of instrumentation include; debriding the root canal system, continuously tapering in a conical form and maintain the original shape and position of the apical foramen.To overcome the inconveniences of manual filing systems, nickel-titanium (NiTi) rotary shaping techniques were developed. This study was conducted to compare three types of rotary systems of different microstructure (super elastic, R-phase alloy and Controlled memory wire) through the following:
1) Preservation of canal path
Forty five human permanent mandibular first molars were used. Teeth were accessed and the mesiobuccal canals were localized and explored. Teeth were scanned with CBCT before and after preparation to evaluate the change in canal curvature, Mesio-distal transportation and Mesio-distal centring ratio were calculated.
2) Cleaning ability
Thirty single rooted teeth were used. They were prepared using the three different system. The roots were vertically split and the amount of debris were calculated using digital microscope and ImageJ software.
3) Instrument cyclic fatigue
Ten files of each system were used. Five of them were used as perceived (new) and five after preparation of three canals. Cyclic fatigue testing of new and used instruments was performed with a specific device which allowed the instruments to rotate freely inside a Stainless Steel artificial canal. The number of cycles to failure (NCF) was calculated by the following equation:
NCF= speed (rpm) X time (in seconds)
4) SEM of the fractured part
Representative samples from all the previous groups of files was prepared for SEM examination to evaluate the presence of any change after the usage and fracture.
5) Differential Scanning Calorimetry (DSC)
Four to five mm of Revo-S, twisted files and Hyflex CM were used. The DSC analyses was conducted over a temperature ranging from -100 oC to 100 oC.
6) Xray diffraction (XRD)
Segments from the shank portions of NiTi files was cut into approximately 8-mm. They were adhered together and ground to obtain a plane. Then peaks was identified.
1) Preservation of canal path
Forty five human permanent mandibular first molars were used. Teeth were accessed and the mesiobuccal canals were localized and explored. Teeth were scanned with CBCT before and after preparation to evaluate the change in canal curvature, Mesio-distal transportation and Mesio-distal centring ratio were calculated.
2) Cleaning ability
Thirty single rooted teeth were used. They were prepared using the three different system. The roots were vertically split and the amount of debris were calculated using digital microscope and ImageJ software.
3) Instrument cyclic fatigue
Ten files of each system were used. Five of them were used as perceived (new) and five after preparation of three canals. Cyclic fatigue testing of new and used instruments was performed with a specific device which allowed the instruments to rotate freely inside a Stainless Steel artificial canal. The number of cycles to failure (NCF) was calculated by the following equation:
NCF= speed (rpm) X time (in seconds)
4) SEM of the fractured part
Representative samples from all the previous groups of files was prepared for SEM examination to evaluate the presence of any change after the usage and fracture.
5) Differential Scanning Calorimetry (DSC)
Four to five mm of Revo-S, twisted files and Hyflex CM were used. The DSC analyses was conducted over a temperature ranging from -100 oC to 100 oC.
6) Xray diffraction (XRD)
Segments from the shank portions of NiTi files was cut into approximately 8-mm. They were adhered together and ground to obtain a plane. Then peaks was identified.
Other data
| Title | Comparison between Three Rotary Nickel Titanium Systems with different Microstructure | Other Titles | مقارنة بين ثلاثة أنظمة دوارة من النيكل تيتانيوم ذات تكوين مجهري مختلف | Authors | Tarek Moustafa Abdel Aziz | Issue Date | 2015 |
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