Introducción: el tratamiento de conduc-tos produce cambios físico-químicos en la dentina y una pérdida estructural significativa para el diente, lo que lo hace más susceptible a la fractura. Material y métodos: 64 premolares mandibulares fueron decoronados y divididos aleatoriamente en cuatro grupos (n=16): grupo control (CG) no tratado, grupo instrumentado ProTaperGold® (PTG®) (25.08), grupo instrumentado ProTaperNext® (PTN®) (25.06) y grupo instrumen-tado WaveOne Gold PRIMARY® (WOG®) (25.07). Durante la instrumentación, se realizó la irrigación con NaOCl al 5,25% con una jeringa Monoject® y tras la instrumentación, las muestras se irrigaron con NaOCl, EDTA 17% y NaOCl activado sónicamente. Los conductos radiculares se obturaron utilizando el sistema B&L®, y posteriormente se colocaron en bloques de resina acrílica estandarizados para ser cargados con una fuerza vertical constante de 0,02 mm/s hasta que se produjo la fractura de la raíz, mediante una máquina de ensayo universal (ME-405/20, Servo-sis®). Las comparaciones entre grupos se analizaron con la prueba ANOVA.Resultados: No hubo diferencias estadísticamente signific...
Introduction: root canal treatment produces physicist-chemist changes in the dentine and a significant structural loss for the tooth what makes it more susceptible to fracture. Material and methods: 64 mandibular premolar were decoronated and randomly divided into four groups (n=16): control group (CG) non-treated, ProTaper Gold™ (PTG™) instrumented group (25.08), ProTaper Next™ (PTN™) instrumented group (25.06) and WaveOne Gold™ PRIMARY (WOG™) instrumented group (25.07). While shaping, cleaning was done with NaOCl 5,25% using a Monoject™ syringe and after shaping, roots were irrigated with NaOCl, EDTA 17% and NaOCl sonically activated. Root canals were obturated using B&L™ system, embedded into standardized acrylic resin blocks and load with a constant vertical force of 0,02 mm/s until root fracture was produced using a universal testing machine (ME-405/20, Servosis™). Comparisons among groups were analyzed with ANOVA test. Results: There were no statistically significant differences (p> 0.05) between the CG and the groups instrumented with PTN™ and WOG™; neither among PTN™ and WOG™ groups. However, statistically significant differences were obtained between the group instrumented with PTG™ and ...