NiTi-alloy archwires are used in dental medicine for tooth positioning. Failures are reported during the mounting and operation. It is supposed that these difficulties are results of a simultaneous presence of corrosion and mechanical wear. First, a corrosive medium was examined in order to simulate the conditions in the mouth. Different simulated body fluids were compared with natural saliva using electrochemical methods. The corrosion properties ofthe NiTi dental wire in the as-received state and without the surface oxide film were studied with electrochemical impedance spectroscopy. Tribo-corrosiontests of NiTi in artificial saliva were performed and a relation between the chemical and mechanical wear was studied. After the experiment, the surface was spectroscopically examined. The relation between the chemical and mechanical wear was determined.
COBISS.SI-ID: 2061671
In biomedical applications, NiTi alloys are used mainly because of their favourable shape memory and superelastic properties. However, in many applications the tribocorrosion properties of these alloys can be of critical concern. For this reason the electrochemical and tribocorrosion properties of superelastic NiTi sheet and orthodontic archwire were studied, taking into account their microstructures and the effect of different surface finishes. Inthe case of the electrochemical tests, samples were tested in artificial saliva, whereas in the tribocorrosion tests the experiments were performed in ambient air, distilled water, and artificial saliva, the latter as a corrosivemedium. In these tests, the total wear rate of the alloy samples was determined, together with the corresponding chemical and tribological contributions. It was confirmed that the microstructure of the investigated alloys had a significant effect on the measured electrochemical and tribocorrosion properties.
COBISS.SI-ID: 1982311
The aim of this paper is to analyse the influence of the nature of the orthodontic archwires on the friction coefficient and wear rate against Al2O3. The materials selected as orthodontic archwires were stainless steel and NiTi archwire. Unused and already used dental archwires with oral deposits will be examined in order to define the effect of plaque presence on friction coefficient and the performance of the wire. The roughness and hardness will be defined before and after wear tests. Wear tests will be carried out in an artificial saliva. A relationship between the hardness of the materials and the friction coefficients as well as the effect of material and different surface conditions of the dental archwire will be studied in order to correlate and understand different properties of dental archwires.
COBISS.SI-ID: 2068583