Avaliação do número de canais modelados com limas ProDesign M até sua fratura, simulados em blocos de resina acrílica

Abstract   Aim: The nickel-titanium files with memory control facilitated the preparation of the root canals, due to their main characteristics being the flexibility and safety resulting from the thermal treatment Memory Control (CM). Methods: The present work identified the useful life of the ProDesign M files until their fracture. The instrumentation was performed in the simulated block channels of acrylic resin. In this study 1 set of files and 6 blocks of acrylic resin was used. Each block containing 3 root canals of medium complexity. The instrumentation sequence was as indicated by the manufacturer: the first file was on 05/15, followed by the file 25/01 and then 06/25. Between the use of each instrument the channels were decontaminated with the auxiliary chemical, the chlorhexidine gel gel 2% and irrigated with distilled water. Results: The average number of turns performed by file 15/05 is from 89.8 to 109.2 until patency. The 25/06 file average was 25.1 to 37.3 per canal, up to patency. The 25/01 file offered no resistance to patency. Conclusion: It was concluded that the 15/05 file supports up to 15 canals with a mean of 100 turns per canal, while file 25/06 was able to support up to 13 canals with an average of 31 turns until its fracture. At 15 channels the 25/01 file did not fracture.