Oa. Peters et al., Effects of four Ni-Ti preparation techniques on root canal geometry assessed by micro computed tomography, INT ENDOD J, 34(3), 2001, pp. 221-230
Aim The aim of this study was to compare the effects of four preparation te
chniques on canal volume and surface area using three-dimensionally reconst
ructed root canals in extracted human maxillary molars. In addition, mu CT
data was used to describe morphometric parameters related to the four prepa
ration techniques.
Methodology A micro computed tomography scanner was used to analyse root ca
nals in extracted maxillary molars. Specimens were scanned before and after
canals were prepared using Ni-Ti - K-Files, Light speed instruments, Profi
le .04 and GT rotary instruments. Differences in dentine volume removed, ca
nal straightening, the proportion of unchanged area and canal transportatio
n were calculated using specially developed software.
Results Instrumentation of canals increased volume and surface area, Prepar
ed canals were significantly more rounded, had greater diameters and were s
traighter than unprepared canals. However, all instrumentation techniques l
eft 35% or more of the canals' surface area unchanged. Whilst there were si
gnificant differences between the three canal types investigated, very few
differences were found with respect to instrument types.
Conclusions Within the limitations of the mu CT system, there were few diff
erences 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 biomechanic
al aspects of root canal preparation.