Evaluation of cutting capacity, apical deviation, runtime and morphological changes in Flexofile, ProTaper® Manual and Prodesign M® instruments after preparation of curved channels

Vol. 10 – Number 40 – 2019 CLINICAL DENTISTRY BOOKLET Original article / Original article Page 115-122 Evaluation of cutting capacity, apical deviation, runtime and morphological changes in Flexofile, ProTaper® Manual and Prodesign M® instruments after preparation of curved channels Sheila Machado dos Passos Zini1 Daniel Galafassi1 Tiago André Fontoura de Melo2 Summary The present study aims to analyze execution time, cutting capacity, occurrence of apical deviation and morphological changes in manual endodontic instruments. Forty-five simulated channels with 35° curvature were divided into three groups according to the type of instrument tested: Flexofile, ProTaper® Manual and Prodesign M®. To analyze the cutting capacity, the channels were weighed on an analytical scale before and after preparation. The difference in weighing was used for calibration. The time for the preparation was timed. For the analysis of the deviation at 1 mm from the CT, before and after the preparation, the channels were filled with ink and photographed. With the overlapping of the images, the measurement of the deviations was performed. The tip region of instruments #25 (Flexofile), F2 (ProTaper® Manual) and #25/.06 (Prodesign M®) was observed in SEM before the first use and after the first, third and fifth use. The images were analyzed by two evaluators for distortion of the spirals. The data of execution time, occurrence of deviation and cutting capacity were submitted to ANOVA, complemented by Tukey’s test. The chi-square test was used for morphological analysis of the instruments. Significance level of 5%. The Prodesign M® instruments had a shorter preparation time. Although the instruments tested had the same cutting capacity, the Flexofiles promoted greater occurrence of apical deviation. As for the morphological changes after use, only the Flexofiles showed signs of stretching of their spirals. Keywords: Endodontics, dental instruments, root canal preparation, scanning electron microscopy.   ¹ Graduated in Dentistry – Centro Universitário da Serra Gaucha. ² Graduated in Dentistry – UFRGS.