|
KMID : 1035320140410010009
|
|
Korean Society for Dental Materials
2014 Volume.41 No. 1 p.9 ~ p.18
|
|
|
Assessment of torque and apical load during root canal preparation using reciprocating nickel-titanium files
|
|
Yoo Yeon-Jee
Lim Bum-Soon
Kim Jin-Woo
Baek Seung-Ho
Lee In-Bog
|
|
|
Abstract
|
|
|
|
The purpose of this study was to investigate the torque and apical load generated during root canal preparation using reciprocating nickel-titanium (NiTi) files in reciprocating or continuous rotating motions. Twenty resin blocks with simulated L-shaped canal were pre-prepared and randomly assigned to four experimental groups for canal preparation: Group RPR, Reciproc R25 file in reciprocating motion; Group RPC, Reciproc R25 file in continuous rotating motion; Group WOR, WaveOne Primary file in reciprocating motion; Group WOC, WaveOne Primary file in continuous rotating motion. The apical load and torque generated during canal preparation were recorded using the laboratory-made load-torque measurement device, and analyzed with the torsional properties of the files. When the files were used in reciprocating motion, the number of pecking stroke, the peak apical load and peak reverse apical load were significantly higher (p<0.05), whereas the peak torque was not significantly different (p>0.05). The peak torque and peak reverse apical load in Reciproc R25 were significantly higher than in WaveOne Primary (p<0.05). The peak torque and peak reverse apical load were positively correlated. The two NiTi files showed bi-phasic elastic deformation under torsional stress, and Reciproc R25 maintained elastic property to higher rotational angles compared to WaveOne Primary (p<0.05). The torque values at yield point and maximum point, and toughness value under fracture point were not significantly different between the files (p>0.05). In conclusion, the torque and apical load during canal preparation differed according to the files and rotating method. Within the limitations of the present study, Reciproc R25 showed significantly higher torque and reverse apical load in both reciprocating and continuous rotating motions, thus requires caution in clinical application.
|
|
|
KEYWORD
|
|
|
apical load, NiTi file, reciprocating motion, torque, yield point
|
|
|
FullTexts / Linksout information
|
|
|
|
|
Listed journal information
|
|
|
|