Thesis (D.S) - Ain Shams University . Faculty of Dentistry Endodontics .

Includes Bibliographical References .

One of the main objectives of the root canal treatment is the shaping and cleaning of the root canal without changing the outline of the root canal from the preoperative shape.
Nickel Titanium files are some of tools used in producing proper cleaning and shaping of the root canal. These files have different designs that vary in its shaping and cleaning ability.
The purpose of this study is to compare and evaluate the shaping and cleaning ability of two single NiTi systems which were WaveOne and One Shape files.
The first part of this study was concerned by the evaluation and comparison of shaping ability of both systems regarding transportation and centering ability using the direct digital radiography and the images superimposition.
The second part of this study was concerned by the evaluation and comparison of cleaning efficiency of both systems regarding the amount of debris in the different canal thirds using the stereomicroscopeand the ability to reduce bacterial load.
The third part was concerned to study the cyclic fatigue resistance as well as the torsional strength of both tested file systems.
The collected data was tabulated, statistically analyzed and illustrated graphically. The results of this investigation revealed that:
• Greater percent in the degree of apical transportation was achieved by using One Shape file systems.
• WaveOne files showed better centering ability in the canal than the One Shape files.
• WaveOne files produced cleaner canal in all canal thirds (apical,middle and coronal levels) regarding to the percent of debris.
• Both systems reduced the bacterial load significantly without difference.
• WaveOne achieved better cyclic fatigue resistance and torsional strength than One Shape file.

Text in English , summary in English & Arabic .