美觀矯正線機械性質的研究－－研究論文

An Investigation on Mechanical Properties of Esthetic Orthodontic Archwires

隨著時代潮流演進，人們越來越重視外表容貌，民眾對於矯正器材的美觀要求也越來越高。本篇研究的目的，在於探討經表面處理之後的鎳鈦美觀矯正線材料，其機械性質是否有所改變。在本篇研究中我們利用萬用試驗機作拉伸試驗，比較經過表面塗層的鎳鈦矯正線跟傳統沒有塗層的鎳鈦矯正線的機械強度。另外利用浸泡試驗，模仿線材在患者口中的情形，查看經過21天的人工唾液浸泡，加上刷牙的磨耗之後，矯正線表面的塗層脫落的情況。拉伸試驗的測量結果顯示，表面塗層並不會影響線材本身的機械強度，有塗層的鎳鈦矯正線與沒有塗層的鎳鈦矯正線並無顯著差異。而在荷重-位移曲線圖中，有塗層的鎳鈦矯正線線與沒有塗層的鎳鈦矯正線極相似。可是在浸泡試驗中，環氧樹脂塗層的矯正線，會因為刷牙的磨耗產生塗層脫落，鐵氟龍塗層的矯正線相對比較不易產生塗層脫落。矯正醫師使用有塗層的矯正線，不會影響矯正治療效果；但為達成患者美觀的要求，則需進一步研發不會脫落的塗層材料。

The main purpose of this study was to investigate the mechanical properties of Ni-Ti coated orthodontic archwires after surface modification. Universal test machine was used to measure the tensile strength of four groups of coated Ni-Ti wires and uncoated control group. Immersion test was applied for 21 days to discover whether the coating would peel off under friction and brushing after immersion. Student's t-test was used to explore any difference between three groups of coated wires and uncoated conventional wires in mechanical properties. The results showed no statistical difference exists between coated Ni-Ti wires and conventional uncoated wires regarding to tensile strength. The load-displacement curve of both wires looked similar. The coating has no effect on the mechanical strength of the base wire. However, after the 21-day immersion test, the epoxy resin coatings were more likely to peel off than Teflon coatings under friction and brushing (P< 0.05). There was no statistical difference between coated wires and conventional uncoated wires with regard to mechanical tensile strength. While orthodontists can achieve the same expected treatment result with esthetic wires, the issue of preventing coatings from peeling off needs further studies.