Ghaffari Hassanali, Mirhashemi Amirhossein, Baherimoghadam Tahereh, Azmi Amir, Rasooli Reza
Assistant Professor, Department of Orthodontics, School of Dentistry, Shahed University of Medical Sciences, Tehran, Iran.
Associate Professor, Dental Research Center, Dentistry Research Institute, Tehran University of Medical Sciences, Tehran, Iran; Department of Orthodontics, School of Dentistry, Tehran University of Medical Sciences, Tehran, Iran.
J Dent (Tehran). 2017 Sep;14(5):259-266.
This study sought to compare enamel cracks after orthodontic bracket debonding in the surfaces prepared with erbium, chromium: yttrium-scandium-galliumgarnet (Er,Cr:YSGG) laser and the conventional acid-etching technique.
This in-vitro experimental study was conducted on 60 sound human premolars extracted for orthodontic purposes. The teeth were randomly divided into two groups (n=30). The teeth in group A were etched with 37% phosphoric acid gel, while the teeth in group B were subjected to Er,Cr:YSGG laser irradiation (gold handpiece, MZ8 tip, 50Hz, 4.5W, 60μs, 80% water and 60% air). Orthodontic brackets were bonded to the enamel surfaces and were then debonded in both groups. The samples were inspected under a stereomicroscope at ×38 magnification to assess the number and length of enamel cracks before bonding and after debonding. Independent-samples t-test was used to compare the frequency of enamel cracks in the two groups. Levene's test was applied to assess the equality of variances.
No significant difference was noted in the frequency or length of enamel cracks between the two groups after debonding (P>0.05).
Despite the same results of the frequency and length of enamel cracks in the two groups and by considering the side effects of acid-etching (demineralization and formation of white spot lesions), Er,Cr:YSGG laser may be used as an alternative to acid-etching for enamel surface preparation prior to bracket bonding.
本研究旨在比较在使用铒铬：钇钪镓石榴石（Er,Cr:YSGG）激光制备的表面和传统酸蚀技术制备的表面上进行正畸托槽拆除后牙釉质裂纹的情况。
本体外实验研究在60颗因正畸目的拔除的健康人前磨牙上进行。将牙齿随机分为两组（n = 30）。A组牙齿用37%磷酸凝胶酸蚀，而B组牙齿接受Er,Cr:YSGG激光照射（金色机头，MZ8尖端，50Hz，4.5W，60μs，80%水和60%空气）。将正畸托槽粘结到牙釉质表面，然后在两组中拆除托槽。在体视显微镜下以×38放大倍数检查样本，以评估粘结前和拆除后牙釉质裂纹的数量和长度。使用独立样本t检验比较两组中牙釉质裂纹的频率。应用Levene检验评估方差齐性。
拆除托槽后，两组之间牙釉质裂纹的频率或长度均无显著差异（P>0.05）。
尽管两组中牙釉质裂纹的频率和长度结果相同，并且考虑到酸蚀的副作用（脱矿和白斑病变的形成），但Er,Cr:YSGG激光可作为酸蚀的替代方法，用于在粘结托槽前制备牙釉质表面。
