THE DIFFERENCE OF SURFACE MORPHOLOGY AND CHEMICAL COMPOSITION OF SUPER-ELASTIC NICKEL TITANIUM ORTHODONTIC WIRES BEFORE AND AFTER IN ARTIFICIAL SALIVA SUBMERSION

Abstract

Objective: In order to Investigate the difference of morphology and composition of Super-elastic Nickel
Titanium wire before and after submersed in artificial saliva with normal pH (pH 6:50) and acidic pH (pH
3.75). Material and method: Super-elastic Nickel Titanium wire were divided into 2 groups. Each group
consisted of 3 samples submerged in 150 ml of artificial saliva for 28 days. The first group was Super-elastic
Nickel Titanium wire submersed in artificial saliva with normal pH (pH 6.50) while the second group was
submersed in artificial saliva with acidic pH (pH 3.75). Wire surface morphology was Analysed using Scanning
Electron Microscope (SEM) while the wire composition was Analysed using Energy Dispersive X-ray
Spectroscopy (EDS. Result: Scanning Electron Microscope revealed a significant difference of surface
morphology of super-elastic nickel titanium before and after submersed in artificial saliva between normal pH
(pH 6.0) and acidic pH (pH 3.75). SEM investigation Showed a fibrous microstructure on the surface of superelastic
nickel titanium before submersed in artificial saliva and became rough and showed many form of pitting
or crevice corrosion after submersed in artificial saliva for 28 days. The chemical compositions in surface
morphology were analysed using EDS Also showing a different result. The major compositions of super-elastic
nickel titanium wire were the C, N, Ni and Ti and after submersed in artificial saliva for 28 days has made any
additional elements O, Al, Si, P, Cl, Ca, K and Fe. Conclusion: the surface morphology of nickel titanium
surface rugosity greater SEM Showed and presence of many forms of pitting or crevice corrosion after
submersed in artificial saliva with normal pH and acidic pH. The major surface composition of a super-elastic
nickel titanium before submersed in artificial saliva were the C, N, Ni and Ti and as a major composition of
super-elastic nickel titanium before and after submersed in artificial saliva with normal pH (pH 6.0) and acidic
pH (pH 3.75 ).