[The surface of various files of quadrangular, triangular and rhomboidal section using scanning electron microscopy].

Using a scanning electron microscope, 45 new files were examined, taken at random, of 5 different brands, of 3 different calibres and with rectangular, triangular and rhomboidal sections. Various defects were observed in the surface of all of them, such as adhered metallic fragments, burrs, deformed teeth, pores and ridges. These defects were more evident on the smaller diameter files of those studied and on those of triangular or rhomboidal section.