RESUMO
The surface characteristics of two Ultrafil materials, Regular set (RS) and Firm set (FS) were analyzed by scanning electron microscopy (SEM). The samples of Ultrafil were obtained from both RS and FS cannules which were pre-heated to 70 degrees C. Another RS and FS samples were obtained at room temperature from un-heated cannules. Samples of standard gutta-percha points obtained from the same manufacturer were studied for comparative purposes. RS samples obtained from pre-heated and un-heated cannules exhibited rough surfaces containing randomly distributed crystal-like structures. Heated and un-heated FS samples featured smoother surfaces with fewer crystal-like structures. The gutta-percha points also exhibited smooth surfaces and absence of crystal-like structures. The consequence of the possible release of these structures from Ultrafil in a biological system is discussed.