2017, Vol. 3 Issue 2, Part D
Comparative evaluation of dynamic torsional resistance of the nickel titanium instruments manufactured with different technologies
AUTHOR(S): Vaikunth Aggarwal, Dr. Vipin Arora and Sachin Gupta
ABSTRACT:Aims: To compare and evaluate the dynamic torsional resistance of nickel titanium instruments manufactured with different technologies. Methods: 60 new rotary NiTi instruments were selected and divided into 4 subgroups of 15 files each: Protaper (Dentsply Maillefer, Ballaignes, Switzerland) based on coventional SE wire technology, Twisted file (Sybron Endo, Orange, CA) based on R-phase technology, Hyflex CM (Coltene Whaledent, Cuyahoga Falls, Ohio) based on Controlled Memory and Protaper Next (Dentsply Maillefer, Ballaignes, Switzerland) based on M-wire technology. A customised stainless steel apparatus consisting of block with a cubical hole (5mm×5mm×5mm) and assembly for holding and adjusting the handpiece was fabricated. 5 mm of the tip of each file was embedded in this composite resin block, and a uniform torsional stress at a speed 300 rpm and 1.8 N.cm torque were applied repetitively by an endodontic motor (X-Smart; Dentsply Maillefer, Ballaigues, Switzerland) with auto-stop mode until the file subjected to torsional failure. The number of load applications leading to fracture were recorded. All fractured surfaces were examined under the SEM for determining the mode of fracture. Tabulated data was statistically analysed using mean and standard deviation. ANOVA and Unpaired ‘t’ test were applied to find the significant difference between the different groups. Results:Protaper files showed significantly higher dynamic torsional Resistance followed by Protaper Next (45.2), Hyflex CM (2.733) and lowest values were obtained for Twisted file but there was no statistical difference between Hyflex CM and Twisted file groups. SEM examination revealed a typical pattern of torsional fracture for all the groups characterized by circular abrasion marks and skewed dimples near the center of rotation Conclusions: Protaper files showed comparatively and significantly higher dynamic torsional resistance than all other file systems followed by Protaper Next, Hyflex CM and Twisted files. Hyflex CM and Twisted files exhibited the same dynamic resistance to torsion.
Pages: 202-205 | 983 Views 8 Downloads
How to cite this article:
Vaikunth Aggarwal, Dr. Vipin Arora, Sachin Gupta. Comparative evaluation of dynamic torsional resistance of the nickel titanium instruments manufactured with different technologies. Int J Appl Dent Sci 2017;3(2):202-205.