TY - JOUR
T1 - Deflecting load of nickel titanium rotary instruments during cyclic fatigue
AU - Jamleh, Ahmed
AU - Kobayashi, Chihiro
AU - Yahata, Yoshio
AU - Ebihara, Arata
AU - Suda, Hideaki
PY - 2012
Y1 - 2012
N2 - The dispersion of the lifetime of NiTi instruments, and their deflecting load (DL) changes during cyclic fatigue were investigated. A total of 120 ProFile NiTi rotary instruments were tested using a specially designed cyclic fatigue testing apparatus with three pins. Using these pins, the instrument was bent and rotated at 300 rpm to fracture. DL was recorded using a load cell attached to the central pin. For each sample, the working time was converted to number of cycles to fracture (NCF) and the mean DL (DLm) was calculated. The averages of NCF and DLm of 120 samples were 584.3±180.5 cycles and 6.44±0.91 N, respectively. All samples showed a sequential decrease in DL during rotation. Based on the present study, it is impossible to estimate the lifetime of a NiTi instrument from NCF. Thus, the change in DL could be an alternative criterion to determine the remaining lifetime.
AB - The dispersion of the lifetime of NiTi instruments, and their deflecting load (DL) changes during cyclic fatigue were investigated. A total of 120 ProFile NiTi rotary instruments were tested using a specially designed cyclic fatigue testing apparatus with three pins. Using these pins, the instrument was bent and rotated at 300 rpm to fracture. DL was recorded using a load cell attached to the central pin. For each sample, the working time was converted to number of cycles to fracture (NCF) and the mean DL (DLm) was calculated. The averages of NCF and DLm of 120 samples were 584.3±180.5 cycles and 6.44±0.91 N, respectively. All samples showed a sequential decrease in DL during rotation. Based on the present study, it is impossible to estimate the lifetime of a NiTi instrument from NCF. Thus, the change in DL could be an alternative criterion to determine the remaining lifetime.
KW - Deflecting load
KW - NiTi rotary file
KW - Number of cycles to fracture
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U2 - 10.4012/dmj.2011-233
DO - 10.4012/dmj.2011-233
M3 - Article
C2 - 22673468
AN - SCOPUS:84861853738
SN - 0287-4547
VL - 31
SP - 389
EP - 393
JO - Dental Materials Journal
JF - Dental Materials Journal
IS - 3
ER -