Evaluation of deformation and fracture rates for nickel-titanium rotary instruments according to the frequency of clinical use

Authors : Ayça YILMAZ, Sıtkı Selçuk GÖKYAY, Rüştü DAĞLAROĞLU, İşıl KARAGÖZ KÜÇÜKAY

Pages : 89-93

View : 23 | Download : 12

Publication Date : 2018-05-01

Article Type : Research Paper

Abstract :DOI : 10.26650/eor.2018.461 Purpose To evaluate the deformation and fracture rates for ProTaper Universal insert ignore into journalissuearticles values(PTU); nickel-titanium rotary instruments according to the frequency of clinical use. Materials and Methods A total of 619 PTU instruments insert ignore into journalissuearticles values(S1, S2, F1, F2, and F3); that have been used in the clinic by a single endodontist were collected over a period of 4 years. These instruments were grouped on the basis of one to three insert ignore into journalissuearticles values(Group A);, four to six insert ignore into journalissuearticles values(Group B); and seven to nine insert ignore into journalissuearticles values(Group C); clinical uses insert ignore into journalissuearticles values(one canal = one use);. All instruments were evaluated by a blinded investigator under a stereomicroscope at 15×–45× magnification for the presence of deformation and fracture. Results The overall rates of deformation and fracture were 10% and 1.2%, respectively. The deformation and fracture rates for the S2, F1, and F2 instruments showed no significant differences among groups. However, fracture rate for S1 instruments in Group A was significantly higher than for those in Group B insert ignore into journalissuearticles values(p=0.025); and Group C insert ignore into journalissuearticles values(p=0.004);. In Group C, the S1 instruments showed a significantly higher deformation rate compared with the S2 insert ignore into journalissuearticles values(p=0.04);, F1 insert ignore into journalissuearticles values(p=0.008); and F2 insert ignore into journalissuearticles values(p=0.049); instruments; there were no other significant differences within groups. Conclusion Under the conditions of the current study, frequency of use seemed to influence the deformation rates of PTU rotary instruments. Except S1, these instruments could be used without any fracture or deformation in up to 9 clinical cases by an experienced endodontist.
Keywords : NiTi rotary system, ProTaper Universal, dental instruments, deformation, fracture