Li Song, Hobson Ross S, Bai Yuxing, Yan Zhuoqun, Carrick Thomas E, McCabe John F
Faculty of Stomatology, Capital University of Medical Sciences, People's Republic of China.
Eur J Orthod. 2007 Dec;29(6):550-4. doi: 10.1093/ejo/cjm046. Epub 2007 Sep 4.
The aim of this study was to manufacture and test, in vitro, a novel modification to provide fluoride-releasing orthodontic brackets. Thirty-two orthodontic brackets were drilled to produce a recess (approximately 1.3 mm in diameter and 0.7 mm in depth) at the centre of the bracket base. Four materials, with and without the addition of sodium fluoride, a glass ionomer cement (Ketac Cem micro), a resin-modified glass ionomer cement (RMGIC; GC Fuji Ortho LC), a zinc phosphate (Zinc Cement Improved), and a resin (Transbond XT) were used to fill the recess in the bracket base. Fluoride release was measured daily during the first week and then weekly for 10 weeks. An ion chromatograph with suppressed conductivity was used for free fluoride ion determination. Statistical analysis to determine the amount of flouride release was undertaken using analysis of variance and Tukey's test. During the first 2 weeks, the resin group, with the addition of 38 per cent sodium fluoride added, released significantly more free fluoride (P < 0.05), but after 2 weeks the fluoride release markedly decreased. After 5 weeks, the RMGIC group, with 15 per cent added sodium fluoride, had significantly higher (P < 0.05) daily fluoride release than the other groups. The findings demonstrated that an appropriate fluoridated material can be used as a fluoride-releasing reservoir in a modified orthodontic bracket to enable it to release fluoride over the period of fixed appliance treatment.
本研究的目的是体外制造并测试一种新型改良方法，以提供可释放氟化物的正畸托槽。三十二个正畸托槽在托槽基底中心钻出一个凹槽（直径约1.3毫米，深度0.7毫米）。使用四种材料，分别添加和不添加氟化钠，一种玻璃离子水门汀（Ketac Cem micro）、一种树脂改性玻璃离子水门汀（RMGIC；GC Fuji Ortho LC）、一种磷酸锌（改进型锌水门汀）和一种树脂（Transbond XT）来填充托槽基底的凹槽。在第一周每天测量氟化物释放量，然后在接下来的10周每周测量一次。使用抑制电导的离子色谱仪测定游离氟离子。使用方差分析和Tukey检验进行统计分析以确定氟化物释放量。在最初的2周内，添加了38%氟化钠的树脂组释放出显著更多的游离氟（P<0.05），但2周后氟化物释放量明显下降。5周后，添加了15%氟化钠的RMGIC组每日氟化物释放量显著高于其他组（P<0.05）。研究结果表明，一种合适的含氟材料可作为改良正畸托槽中释放氟化物的储存器，使其能够在固定矫治器治疗期间释放氟化物。
