Comparative study of surface defects of Reciproc and Wave One Gold files after instrumentation of root canals in extracted molars using Scanning Electron Microscopy (SEM).

Abstract

In the present investigation, the surface defects found in reciprocating files, Reciproc 25.08 and Wave One Gold Primary 25.07, were compared before and after using 3, 6 and 9 opportunities in the instrumentation of root canals with moderate curves of extracted human molars, under observation of MEB. Photographs of the apical third at 500x and of the middle and cervical thirds at 200x were rated by four endodontic experts, who identified defects such as microcracks, stretch marks, craters, deformation of sharp surfaces, blunt borders, presence of a smear layer and fracture of the instrument. The results were submitted to a Kruskal Wallis, chi², ANOCA and t student statistical analysis, given the structure of the non-parametric variables, obtaining conclusions such as, that the Reciproc file has fewer surface defects than Wave One Gold; however, a direct relationship of these to the fracture was not found, since the Reciproc file broke more than the Wave One Gold, but statistically none of the two systems showed a significant fracture index in order to conclude that lime is more separated. A direct relationship was found between the number of surface defects and the number of uses of the instrument, therefore, it can be defined that fewer uses will have less surface defects and less risk of fracture, determining as a recommendation that this type of reciprocating rotary files can be used maximum for three opportunities.