دراسة تحديد أطول فترة صلاحية لأسلاك تقويم الأسنان في أجواء مختلفة

Study to Determine the Longest Validity Period for Orthodontic Wires in A Different Environments

Abstract

ﯿـﺘﻠﺨص اﻟﺒﺤـث ﺒﺘﺤدﯿـد أطـول ﻓﺘـرة ﺼـﻼﺤﯿﺔ ﻷﺴـﻼك ﺘﻘــوﯿم اﻷﺴـﻨﺎن ﻓـﻲ أرﺒـﻊ أﺠـواء أﻛﺎﻟـﺔ ، اﻷول ﺠـو ﻤﻤﺎﺜـل ﻟﻔــم اﻷﻨﺴﺎن ﺘﻘرﯿﺒـﺎ" ﻤـن ﺤﯿـث اﻟوﺴـط اﻷﻛـﺎل )اﻟﻠﻌـﺎب اﻟﺼـﻨﺎﻋﻲ((Artificial Saliva) و درﺠـﺔ اﻟﺤـرارة واﻟﺤﺎﻤﻀـﯿﺔ واﻟﺘﻬوﯿـﺔ،  وﻤﻘﺎرﻨﺘﻬـــﺎ ﺒﺎﻷﺴـــﻼك اﻟﻌﺎﻤﻠـــﺔ ﻓـــﻲ ﻨﻔـــس اﻟوﺴـــط اﻷﻛـــﺎل واﻟﺘﻬوﯿـــﺔ وﻟﻛـــن ﺒدرﺠـــﺔ ﺤـــرارة اﻟﻐرﻓـــﺔ ﻛﺠـــو أﻛـــﺎل ﺜـــﺎﻨﻲ، ﺜـــم اﻷﺴـــﻼك اﻟﻤﺘواﺠدة ﻓﻲ ﻤﺤﻠول ﻛﻠورﯿد اﻟﺼودﯿوم wt NaCl)٪٣,٥( ﺒـدﻻ" ﻋـن اﻟﻠﻌـﺎب اﻟﺼـﻨﺎﻋﻲ وﺒدرﺠـﺔ ﺤـرارة اﻟﻐرﻓـﺔ وﺒـﻨﻔس اﻟﺘﻬوﯿـﺔ ﻛﺠو أﻛﺎل ﺜﺎﻟث وأﺨﯿرا" اﻟﻤﻘﺎرﻨﺔ ﻤﻊ اﻷﺴﻼك اﻟﻤﺘواﺠدة ﻓﻲ ﻤﺤﻠول ﻛﻠورﯿـد ااﻟﺼـودﯿوم وﺒدرﺠـﺔ ﺤـرا رة ﺠﺴـم اﻷﻨﺴـﺎن وﻤﻌرﻀـﺔ ﻟــﻨﻔس اﻟﺘﻬوﯿــﺔ أﯿﻀــﺎ". وﺘﻤــت اﻟدراﺴــﺔ ﺒﺄﺴــﺘﺨدام ﻤﻨظوﻤــﺔ ﻤﺼــﻤﻤﺔ و ﻤﺼــﻨﻌﺔ ﻤﺤﻠﯿــﺎ" ﺤﺴــب اﻟﻤواﺼــﻔﺔ اﻟﻘﯿﺎﺴــﯿﺔ اﻷﻤﯿرﻛﯿـــﺔ اﻟﻤﻌدﻟــﺔ )(ASTM G٣١، وأﺴــﻼك ﺘﻘــوﯿم اﻷﺴــﻨﺎن اﻟﻤﺴــﺘﺨدﻤﺔ ﻤــن ﻨــوع اﻟﻔــوﻻذ اﻟﻤﻘــﺎوم ﻟﻠﺼــدأ اﻷوﺴــﺘﻨﺎﯿﺘﻲ )٣٠١(، وﺒﻌــد إﺠـراء أﺨﺘﺒـﺎرات اﻟﺘﺂﻛـل اﻷرﺒﻌـﺔ أﻋـﻼﻩ و ﻟﻔﺘـرة زﻤﻨﯿـﺔ ﻤﻘـدارﻫﺎ ﺴـﺘﺔ أﺸـﻬر ﻤﺘﺘﺎﻟﯿـﺔ وﺒﺄﺴـﺘﺨدام ﻗـﺎﻨون ﻤﻌـدل ﺘﻐﻠﻐـل أوﻤﻌـدل ﻨﻔـﺎذ ﺘﻨﻘـر اﻟﺘﺂﻛـل )(Corrosion Penetration Rate وﺒـﺎﻟطرق اﻟرﯿﺎﻀـﯿﺔ اﻟﺘﻘﻠﯿدﯿـﺔ وﻤـن اﻟﺼـور اﻟﻤﺠﻬرﯿـﺔ ﻟﻠﻌﯿﻨـﺎت ﻗﺒـل وﺒﻌـد ﺤــﺎﻻت اﻟﺘﺂﻛــل ﻨﺴــﺘﻨﺘﺞ ﺒــﺄن اﻷﺴــﻼك ﺘﻛــون ﺒﻔﺘــرة ﺼــﻼﺤﯿﺔ أطــول ﻋﻨــد ﺠــو ﻤﻤﺎﺜــل ﻟﻔــم اﻷﻨﺴــﺎن وﺘﻠﯿﻬــﺎ اﻷﺴــﻼك اﻟﻌﺎﻤﻠــﺔ ﻓــﻲ اﻟﻠﻌﺎب اﻟﺼﻨﺎﻋﻲ وﻋﻨد درﺠﺔ ﺤرارة اﻟﻐرﻓﺔ ﺜم ﺘﻠﯿﻬـﺎ اﻷﺴـﻼك اﻟﻌﺎﻤﻠـﺔ ﻓـﻲ ﻛﻠورﯿـد اﻟﺼـودﯿوم ﻋﻨـد درﺠـﺔ ﺤـرارة اﻟﻐرﻓـﺔ و أﻗﺼـر

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 presents 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.