engleski

Effect of the pH of Artificial Saliva on Mechanical Properties of Orthodontic Archwires

Objectives: To evaluate the effect of surface coating on mechanical properties of orthodontic archwires after corrosion in artificial saliva of different pH values. Materials and Methods: Six samples of three types of orthodontic archwires in dimension 0.020×0.020’’ were tested: uncoated nickel titanium (NiTi), rhodium coated (RhNiTi) and nitrified (NNiTi). Wires were immersed in artificial saliva solution for 28 days and incubated in a water bath at 37°C. The pH values of artificial saliva solutions were adjusted to 4.8 and 6.6. Unexposed wires were used for comparison. Vickers microindentation hardness test was used to analyse the differences in mechanical properties caused by the corrosion. One-way and two-way ANOVA with the Students- Newman-Keuls post-hoc test were used for evaluation of the differences in microhardness between the type of coating and pH value of the media. Results: One-way ANOVA indicates that RhNiTi is harder than the NiTi and NNiTi are (p<0.05). Two-way ANOVA shows that type of coating influences the microhardness (p<0.001 ; η2=0.309), but the pH value has no impact on the microhardness (p=0.237 ; η2=0.070). The combination of the type of coating and the pH value also did not contribute to the change in microhardness (p=0.510 ; η2=0.089). Conclusions: Mechanical properties of orthodontic archwires are influenced by the type of coating but not by the pH value of the artificial saliva.

mechanical properties; orthodontic archwires; artificial saliva

Izrađeno i financirano u sklopu projekta “Imunosne i regenerativne implikacije korozije dentalnih materijala u djece i adolescenata” Hrvatske zaklade za znanost (IP-2014-09-7500) voditelja Stjepana Špalja