Avaliação da resistência torcional em instrumentos endodônticos Protaper Next, WaveOne e WaveOne Gold após o uso único

• Ano de defesa: 2017
• Autor(a) principal: Paula Ribeiro Garcia
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Minas Gerais
• Palavras-chave em Português: Níquel; Titânio; Resistência de materiais; Instrumentos odontológicos; Torção mecânica; Instrumentos de niti; Instrumentos reciprocantes; Instrumentos rotatórios; Tratamentos termomecânicos; Uso único; Resistência torcional
• Link de acesso: https://hdl.handle.net/1843/ODON-ARKPZX

Niti instruments undergo continuous modifications to improve their performance on shaping canals. This study aimed to assess the torsional resistance among instruments: Protaper Next X1 (X1), Protaper Next X2 (X2), WaveOne Primary (WO) e WaveOne Gold Primary (WOG) before and after use in extracted teeth and the influence of manufacturing characteristics on this behavior. The geometric characterization was performed by measure of diameter and cross-sectional area at 3mm from the tip. Phases constitution was determined by X-ray diffraction. The instruments were divided in two groups: control group (CG) and experimental group (EG). Each one containing seven (n=7) instruments of each type. Torsion tests until the rupture were carried out in CG instruments. The EG instruments were used to shape mesial canals of one mandibular molar and were analyzed by scanning electron microscopy. And them, the same torsion tests were carried out in EG instruments. ANOVA with 95% of confidence level was applied to the results. Mean values of maximum torque of the CG and EG were higher to WO followed by WOG, X2 and X1. This reveals the relation between torsional resistance and geometric characteristics. After use, no differences were found between CG and EG and torsional resistance was maintained. No cracks were found on surfaces of instruments in SEM analyses. Thus, it was concluded that, regardless of whether reciprocating or rotating instruments, single-use or not, a formatting of the curved canals of a molar did not compromise a torsional resistance of the instruments and no lead to the cracks formation.