Analisys of surface alterations of Ni-Ti rotary instruments caused by autoclave sterilization

In recent years, rotary nickel–titanium (NiTi) instruments have become popular because of their superior elasticity and resistance to torsional fracture compared to stainless steel hand files (Walia et al. 1988). Furthermore, most recently it has been shown that a TiN hard coating increased the cutting efficiency of NiTi files significantly. To date, the surfaces of NiTi rotary instruments have been analysed using a variety of different techniques. Scanning Electron Microscopy (SEM) and Atomic Force Microscopy (AFM) were widely used to evaluate the topographical characteristics of different kinds of materials and has been accepted as a suitable method for the evaluation of NiTi instrument surfaces (Tripi et al. 2001, Martins et al. 6 2001, Alpati et al. 2003, 2005). Aim of our study was to evaluate by using scanning electrical microscopy (SEM) with Energy dispersive x-ray spectroscopy (EDS), and Atomic Force Microscopy (AFM) the effect of repeated dry heat sterilization on surface characteristics of NiTi rotary instruments.