金屬矯正之架長期使用於口腔內，因口腔內環境之變化會對金屬產生腐蝕之現象。本研究之目的比較金屬矯正支架新的與經熱處理後之矯正支架進泡於不同pH值環境下經四十八週後，觀察與比較其金屬離子支釋放。金屬矯正裝置經浸泡於不同酸鹼值之緩衝液後，以金屬原子吸收光譜儀分析定 量其中之Ni、Cr、Fe、Cu、Co、Mg等離子。以 ANOVA統計比較差異性。結果發現：一、經熱處理過之矯正支架其金屬梨子釋出量較高。二、於酸之緩衝以中釋放之金屬離子較於中性環境下較高。三、隨著時間增加，四十八週浸泡之矯正支架其釋放金屬離子有增加之現象。研究結果顯示：金屬矯正之架於口腔環境下會發生腐蝕現象。因此如何改善金屬矯正之架之腐蝕反應為日後研究之重要目標。 Objectives. Orthodontic appliances can corrode with time in the mouth. The purpose of this study was to compare the release of metal ions from new and recycled brackets immersed in buffers of different pH values over a 48-week period. The brackets were divided into two groups: new and recycled. The base of the latter was coated with adhesive and the bracket was heat treated before being immersed in test solution for 48 weeks. The release of nickel, chromium, iron, copper, cobalt and manganese ions was analysed by atomic absorption spectrophotometry. Differences were analyzed using one-way analysis of variance. The result showed that (1) The recycled brackets released more ions than the new brackets. (2) Brackets immersed in solutions of pH 4 released more ions than those immersed in solutions of pH 7. (3) The total amount of ions released increased with time over the 48 week immersion period. This study shows that both new and recycled brackets will corrode in the oral environment. To avoid clinical side-effects, metal brackets should be made more resistant to corrosion, and recycled brackets should not be used.
