| Summary: | 碩士 === 中山醫學大學 === 牙醫學系碩士班 === 97 === Abstract
As time goes by, esthetic issue becomes more and more important. People want to get a perfect smile via orthodontic treatment, but they prefer wearing an invisible or tooth- color appliance. Recently the esthetic orthodontic wires become more popular and get more attention! Besides esthetics, other merits were cited in previous studies. One of them is the prevention of corrosion of Ni-Ti wires by surface coating, and thus preventing Nickel ion release. Therefore, it would reduce the possibilities of Nickel hypersensitivity. Although the esthetic wires have some advantages, we still have to know more about their characteristics before widely clinical use. The main purpose of this study was to investigate the mechanical strength of the coated Ni-Ti wires after surface modificatiobn.Universal test machine was used to measure the tensile strength of coated Ni-Ti wires. Second, using artificial saliva to imitate the oral situation, immersion test was applied for 21 days to discover wether the coating would peel off after immersion and friction of brushing. The result showed that there was no statistic difference between coated wires and uncoated conventional wires in tensile strength, and the load-displacement curve of both wires looked simliar. The coating has no effect on mechanical strength of the base wires. However, after 21-day immersion test, the epoxy resin coatings were peeled off more easily than teflon coatings under friction and brushing. The orthodontist may achieve the same expected treatment result with new esthetic wires. But the prevention of coating peeling off needs further study.
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