DIYALA JOURNAL OF ENGINEERING SCIENCES

Abstract

The research summary to knowing longest period of validity for orthodontic wires in four corrosive media ,the first medium approximately similar to human mouth such as corrosive medium (Artificial Saliva), human body temperature, hydrogen power (pH), and aeration ,and compared with orthodontic wires these serve in same corrosive medium but at room temperature and the identical aeration as a second corrosive medium, and compared to orthodontic wires present or attending in sodium chloride solution instead of artificial saliva at room temperature and the like aeration as a third corrosive medium. The final comparison test with orthodontic wires present in sodium chloride solution at human body temperature and the like aeration too.
The study done by using device or system was native designed and manufactured according to modified American standard specification (ASTM G31), the orthodontic wires were from type austenitic stainless steel (301).
After four mentioned corrosion experiments for serial six months period ,and usage Corrosion Penetration Rate law (CPR) and by traditional mathematical methods addition to the microstructures of samples before and after corrosion experiments ,conclude that ;the longest validity period for orthodontic wires at environment approximately similar to human mouth ,then wires worked in artificial saliva at room temperature, followed by the wires served in sodium chloride solution at room temperature, finally; orthodontic wires were worked in sodium chloride solution at human body temperature had shortest validity period.