Ensaio mecânico de torção dos instrumentos protaper universal e protaper gold

Abstract

Nickel and Titanium (NiTi) endodontic instruments have undergone major changes in their characteristics in order to improve mechanical properties and thus provide better clinical performance. This work aimed to compare the torsional resistance of Protaper Gold and Protaper Universal instruments through the torsion test. The torsional resistance was performed in a custom-made device (ISO 3630-1), where a torque was applied to measure the variation of the torsion angle and the torque value until the instrument fractured. Ten Protaper Universal F3 instruments (PTU F3) and ten Protaper Gold F3 instruments (PTG F3) were selected for the test and subjected to the analysis of variance (ANOVA) and Student-Newman-Keuls (SNK) test with a significance level of 5 %. After the results, the maximum torque value until fracture followed the following order: PTG F3> PTU F3 (P <0.05); as for the torsion angle, PTU F3 was superior to PTG F3, but with no statistically significant difference. As it has a higher maximum torque in torsion, the PTG F3 instrument can be recommended for the instrumentation of a severely curved channel, while the PTU F3, which revealed a greater torsion angle, may be more indicated for the instrumentation of a straight or gently curved atresia channel.