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Published on: May 5, 2022
Effects of four Ni-Ti preparation techniques on root canal geometry assessed by micro computed tomography
O A Peters1, K Schönenberger, A Laib
1Department of Preventive Dentistry, Cariology and Periodontology, ETH, University of Zurich, Zurich, Switzerland. peters@zmk.unizh.ch
Aim:
The aim of this study was to compare the effects of four preparation techniques on canal volume and surface area using three-dimensionally reconstructed root canals in extracted human maxillary molars. In addition, micro CT data was used to describe morphometric parameters related to the four preparation techniques.
Methodology:
A micro computed tomography scanner was used to analyse root canals in extracted maxillary molars. Specimens were scanned before and after canals were prepared using Ni-Ti - K-Files, Lightspeed instruments, ProFile.04 and GT rotary instruments. Differences in dentine volume removed, canal straightening, the proportion of unchanged area and canal transportation were calculated using specially developed software.
Results:
Instrumentation of canals increased volume and surface area. Prepared canals were significantly more rounded, had greater diameters and were straighter than unprepared canals. However, all instrumentation techniques left 35% or more of the canals' surface area unchanged. Whilst there were significant differences between the three canal types investigated, very few differences were found with respect to instrument types.
Conclusions:
Within the limitations of the micro CT system, there were few differences between the four canal instrumentation techniques used. By contrast, a strong impact of variations of canal anatomy was demonstrated. Further studies with 3D-techniques are required to fully understand the biomechanical aspects of root canal preparation.
