五种去金属托槽黏结剂方法对牙釉质影响的实验研究

The experimental research of the effects on enamel surface treated with five composite removal methods after metal bracket debonding

目的:通过观测5种不同的去金属托槽釉质黏结剂方法对牙釉质的影响,筛选出一种较为理想的去釉质黏结剂的方法,为临床应用提供实验依据。方法:选择因正畸治疗需要拔除的正常上颌第一前磨牙50颗,按去黏结剂方法不同随机分为5组,每组10颗,记录去黏结时所需操作时间,用万能工具显微镜测量所有牙齿的釉质损失量。并将所有标本在扫描电子显微镜下观察、拍照。结果:实验中5组不同去黏结剂方法所用平均时间均存在显著性差异(P(0.01),去黏结操作所需时间按A组(金刚砂车针组)、B组(不锈钢凸轮组)、D组(金刚砂车针+碳钨车针组)、E组(不锈钢凸轮+碳钨车针组)、C组(碳钨车针组)依次递增。万能工具显微镜测量结果表明5实验组釉质厚度损失量按C组、E组、D组、B组、A组递增,C组、E组同A组、B组、D组的釉质损失量存在显著性差异(P(0.01),C组与E组的釉质损失量无显著性差异(P(0.05)。去黏结剂后电镜观察釉质表面,C组和E组釉质表面规则,无明显划痕,B组和D组釉质表面粗糙,划痕明显,A组釉质表面最为粗糙,可见多数明显深划痕。结论:5组不同去黏结剂方法均造成不同程度的釉质厚度损失和釉质表面的损伤,其中碳钨车针组和不锈钢凸轮+碳钨车针组对釉质影响最小,且不锈钢凸轮+碳钨车针组去黏结所用时间少,因此认为后者是较为理想的去黏结剂方法。

Aim：In this study five composite removal methods for metal bracket debonding were evaluated and compared. The purpose was to find an ideal method for removing residual composite and provide the experimental proof for clinical application. Methods： Fifty healthy maxillary permanent premolar teeth, which were extracted for orthodontic purposes, were collected. They were randomly divided into five groups according to different composite removal methods, 10 in each group. Then residual composite were removed and the time needed was recorded. The universal measuring microscope was used to measure the enamel loss of the teeth. All samples were examined in a scanning electron microscope and photo- graphs were taken. Results： There was a highly statistically difference in time taken among each group（ P 〈 0. 001）, which increased in the following order： group A（ the corundum bur group）, group B（the stainless steel latch group） ,group D（ the corundum bur ＋ carbo-wolfram bur group）, group E（ the stainless steel latch ＋ carbo-wolfram bur group）,group C （the carbo-wolfram bur group）. The enamel loss measured by Universal measuring microscope increased in the following order： group C, group E, group D,group B,group A. There were a statistically difference among group C,greup E and group A, group B or group D（P 〈 0. 001 ）. No statistical difference was found between group C and group E（P 〉 0. 05）in enamel loss. Under SEM the enamel surfaces were f＇me and found no distinct scratch in group C and group E , coarse and found some marked scratch in group B and group D, the most coarse and found many deeply marked scratch in group A. Conclusion：All the five methods introduce enamel loss and surface abrasion in different extent. Those are minimal in the carbo-wolfram bur group and the stainless steel latch ＋ carbo-wolfram bur group, and spend less time in the latter. So, The latter is considered an ideal method for residual composite removal.