|Support type:||Scholarships in Brazil - Scientific Initiation|
|Effective date (Start):||December 01, 2013|
|Effective date (End):||November 30, 2014|
|Field of knowledge:||Health Sciences - Dentistry - Endodontics|
|Principal Investigator:||Fabio Luiz Camargo Villela Berbert|
|Grantee:||Luiza Rossi Rodriguez|
|Home Institution:||Faculdade de Odontologia (FOAr). Universidade Estadual Paulista (UNESP). Campus de Araraquara. Araraquara , SP, Brazil|
The aim of the study is to evaluate the resistance to fatigue fracture of nickel-titanium instruments submitted to dynamic bending test, comparing the reciprocal systems WaveOne and Reciproc, as well as the influence of variation in penetration/traction on the two types of instruments. Will be evaluated twenty instruments of the systems Reciproc (VDW) and Wave One (Dentsply-Maillefer), which are the instruments R25, R40 and R50 of Reciproc system, and Small File 21, Primary File 25 e Large File 40 of Wave One System. all of them with 25 mm length. All instruments will be submitted to bending tests using a device specifically developed for this study. The test apparatus consists of an artificial radicular curved canal, made of tempered stainless steel and has a 5 mm radius and bending angle of 45 °, which will move axially to the instrument at a speed of 120 or 160 dislocations by minute. For all Wave On instruments will be used the program "reciprocation WaveOne all", and for all Reciproc instruments will be used the program "reciprocation Reciproc all". The instruments will be powered by the electric motor Reciproc Silver (VDW). The hand piece of this engine will be coupled with instruments mentioned systems, which will be introduced into the artificial canal and there will be triggered working freely until fracture. The time to fracture will be recorded by a stopwatch and, thereafter, will be calculated the number of cycles performed by the instruments to fracture. The comparison of the average number of cycles performed until fracture will be subjected to statistical analysis after testing for normality. The level of significance is 5%.