正畸粘接用玻璃离子粘固剂防治托槽周围釉质脱矿的体外pH循环实验

Prevention of enamel demineralization adjacent to orthodontic brackets bonded with resin-modified glass ionomer: an in vitro pH cycling study

目的 通过体外pH循环实验研究树脂改良型玻璃离子粘固剂 (resin modifiedglassionomercement)对托槽周围釉质脱矿的抑制作用。方法 选择 5对离体前磨牙 ,实验组用树脂改良型玻璃离子粘固剂粘接托槽 ,对照组用复合树脂粘接剂粘接托槽。全部样本每天进行pH循环实验 ,共60d。用偏振光显微镜观察托槽周围釉质脱矿病损并测量病损体部的深度、面积以及病损边缘与粘接材料边缘的距离。结果 对照组托槽周围釉质脱矿病损的深度和面积均大于实验组 ,配对t检验表明 2组间差异有非常显著性 (P <0 0 0 1 )。实验组病损均远离玻璃离子粘固剂边缘 ,而对照组病损均深入复合树脂粘接剂边缘的下方。

Objective To investigate the resin modified glass ionomer cement for inhibition of enamel demineralization adjacent to orthodontic brackets under a pH cycling experiment. Methods The study used 5 pairs of extracted human premolars. The experiment teeth were bonded with resin modified glass ionomer, and the contral teeth were bonded with composite resin. All samples were under the pH cycling experiment each day for 60 days . Demineralization lesions of enamel adjacent to orthodontic brackets were evaluated with polarized light microscopy. The depth and area of the lesion, the distance between the edge of the adhesive on the enamel surface and the border of the lesion were measured. Results The depth and area of lesions in control group were greater than those in experiment group . Paired t test showed significant differences ( P <0.001). There was always a distance between the lesions border and the glass ionomer cement. In control group, all lesions were developed under the edge of composite resin. Conclusion It was suggested that resin modified glass ionomer could become an orthodontic bonding agent to minimize enamel demineralization.