RESUMO
AIMS: The endodontic literature reports a lot of comparative study on endodontic instruments, concerning as well their geometry, instrumental dynamics, material, mechanical behavior or heat treatment. However, to our knowledge, no study has focused on the influence of endodontic motors on the shaping abilities of endodontic instruments. Thus, the aim of this study was to analyze the influence of the endodontic motors on root canal shaping instruments. METHOD: Dual Move (MICRO-MEGA, Besançon, France), Canal Pro CL2i (COLTENE, Alstätten, Suisse), Canal Pro Jeni Motor (COLTENE, Alstätten, Suisse), Ai Motor (WOODPECKER, Guilin, China), Wave One motor (VDW, Postfach, Munich) and Smart A (WOODPECKER, Guilin, China) were pre-clinically compared in continuous rotation and reciprocating motion on a traction/compression bench using resin blocks. Canal shaping in continuous rotation and reciprocating motion were performed with One Curve and One RECI instruments (MICRO-MEGA, Besançon, France), respectively. The penetration/removal forces, making it possible to objectify the cutting effect and screwing effect of the instruments during root canal shaping, were analyzed. RESULTS: The results showed (i) that endodontic motors influence the mechanical behavior of endodontic instruments, (ii) that the influence of the motors is essentially felt during reciprocating motion and (iii) that the reciprocating angles influence the mechanical behavior of endodontic instruments. CONCLUSION: Only endodontic instruments are widely studied in literature while endodontic motors have a direct influence on root canal treatment. This study analyzes the influence of the endodontic motors on root canal shaping instruments. This study tends to demonstrate that Jeni Motor could optimize the mechanical behavior of endodontic instruments.
RESUMO
INTRODUCTION: This study aims to validate that haptic simulator assistance could distinguish skill levels with haptic simulation in restorative dentistry. MATERIALS AND METHODS: This work was carried out with 93 first-year, 87 third-year and 44 fifth-year dental students. The promotions of first- and fifth-year dental students made one session to represent the negative and the positive controls, respectively. The third-year dental students were the studied population. Whatever the group, the maximum time for each reparation was restricted to 3 min. All students have to perform the same three exercises. The third-year dental students performed four sessions spread over the whole university year. For each test, the total score provided by the simulator was recorded and analysed. RESULTS: The exercises are not discriminating in direct vision while the exercise in indirect vision is very interesting to distinguish the levels of the learners. CONCLUSION: The results underline that the exercises in indirect vision could distinguish different profiles of student having different preclinical and clinical levels, while making it possible to follow the acquisition of clinical competence.