title: SEM observations and differential scanning calorimetric studies of new and sterilized nickel-titanium rotary endodontic instruments.
abstract: Scanning electron microscopy (SEM) and differential scanning calorimetric (DSC) studies were utilized to investigate surface and microstructure of two brands of rotary nickel-titanium (NiTi) endodontic instruments, in the as-received condition and after subjection to 1, 6, and 11 sterilization cycles. A total of 66 ProFile (n = 33) and Flexmaster (n = 33) files were examined. SEM observations indicated the presence of surface imperfections and adherent material in all new and sterilized instruments and an increase in surface roughness of the instruments that underwent multiple sterilizations. DSC measurements showed that the specimens of both brands, in the as-received condition and after 11 sterilizations, were completely austenite in the oral environment temperature, suggesting that they are capable of superelastic behavior in appropriate clinical conditions.
authors.affiliation: Department of Endodontology, Dental School, Aristotle University of Thessaloniki, Thessaloniki, Greece.
authors.forename: Georgia B
authors.initials: GB
authors.lastname: Alexandrou
authors.forename: Konstantinos
authors.initials: K
authors.lastname: Chrissafis
authors.forename: Leonidas P
authors.initials: LP
authors.lastname: Vasiliadis
authors.forename: Eleni
authors.initials: E
authors.lastname: Pavlidou
authors.forename: E K
authors.initials: EK
authors.lastname: Polychroniadis
mesh_terms: D000704:Analysis of Variance; D002152:Calorimetry, Differential Scanning; D003722:Dental Alloys; D003762:Dental Instruments; D003799:Dental Stress Analysis; D004548:Elasticity; D017743:Equipment Reuse; D006358:Hot Temperature; D008855:Microscopy, Electron, Scanning; D009532:Nickel; D018915:Root Canal Preparation / Q000295:instrumentation*; D013242:Sterilization; D013499:Surface Properties; D014025:Titanium
chemical_list: D003722:Dental Alloys; C040654:titanium nickelide; C093824:Martensite; C093826:Austenite; D009532:Nickel; D014025:Titanium