Premium
Torsional Properties Of New And Used Rotary K3 NiTi Files
Author(s) -
Yared Ghassan,
Kulkarni Gajanan K.,
Ghossayn Fadia
Publication year - 2003
Publication title -
australian endodontic journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.703
H-Index - 34
eISSN - 1747-4477
pISSN - 1329-1947
DOI - 10.1111/j.1747-4477.2003.tb00516.x
Subject(s) - torque , fracture (geology) , rotation (mathematics) , nickel titanium , materials science , orthodontics , mathematics , composite material , physics , geometry , medicine , thermodynamics , shape memory alloy
The purpose of this study was to compare torque (gcm) and angle of rotation (degrees) at fracture of new and used NiTi K3 .04 rotary instruments. The relation between size of instrument and torque at fracture was also investigated. The torque and angle of rotation at fracture of new and used NiTi K3 .04 rotary instruments sizes 15 to 40 were determined according to ANSI/ADA Specification No. 28. Analysis of variance was used to compare the torque and angle of rotation at fracture among the different sizes of the new instruments and between new and used instruments of the same size (α = 0.05). The relationship between torque at fracture and size of instrument was determined with a regression analysis. Torque at fracture of the new instruments increased significantly with the diameter (p < 0.05). The used instruments, sizes 25 to 40, had significantly lower torque at fracture values compared to the new ones (p < 0.05). The used instruments, sizes 20 and 35 had significantly lower angle of rotation at fracture compared to the new ones (p < 0.05). A stronger relationship was found between the size of the file and the torque at fracture for the new instruments (p < 0.0001) compared to the used ones (p < 0.0001). The results of the present study suggested that the torque at fracture values of new instruments increased significantly with the diameter. The results also suggested that repeated use of .04 K3 instruments affected mainly the torque at fracture.