Heravi Farzin, Rashed Roozbeh, Raziee Leila
Department of Orthodontics and Dental Research Center, School of Dentistry, Mashhad University of Medical Sciences, Mashhad, Iran.
Aust Orthod J. 2008 Nov;24(2):110-5.
Enamel cracks, which may develop during debonding orthodontic brackets, may jeopardise the integrity of the enamel and detract from the appearance of the teeth.
To compare the adhesive remnant scores (ARI), the number, lengths and directions of enamel cracks before bonding and after debonding metal orthodontic brackets with three different methods.
Metal brackets were bonded with a self-curing orthodontic adhesive to the buccal surfaces of 75 recently extracted upper and lower premolars. The teeth were randomly divided into three groups, and the brackets removed either with a side-cutter, a single-blade bracket remover or a two-blade bracket remover. The number, directions and lengths of the enamel cracks before bonding and after debonding were compared. The number of 'pronounced' cracks (i.e. cracks that could be identified with the naked eye) and the ARI scores in each group were also compared.
After debonding, the number of enamel cracks and pronounced cracks, and the lengths of the enamel cracks increased in all groups (p < 0.001). There were no statistically significant differences between the groups. The ARI scores and the direction of propagation of the enamel cracks were not influenced by the debonding method used (p = 0.73).
Concerns about the enamel damage caused by the three methods of debonding justify caution. Despite widespread use of these methods, it would be sensible to search for methods that result in less enamel damage.
在正畸托槽拆除过程中可能出现的牙釉质裂纹,可能会损害牙釉质的完整性并影响牙齿外观。
比较三种不同方法在粘结和拆除金属正畸托槽前后的粘结剂残留分数(ARI)、牙釉质裂纹的数量、长度和方向。
使用自凝正畸粘结剂将金属托槽粘结到75颗近期拔除的上下颌前磨牙的颊面。将牙齿随机分为三组,分别使用侧切钳、单刃托槽拆除器或双刃托槽拆除器拆除托槽。比较粘结前和拆除后牙釉质裂纹的数量、方向和长度。还比较了每组中“明显”裂纹(即肉眼可见的裂纹)的数量和ARI分数。
拆除托槽后,所有组的牙釉质裂纹和明显裂纹的数量以及牙釉质裂纹的长度均增加(p < 0.001)。各组之间无统计学显著差异。ARI分数和牙釉质裂纹的扩展方向不受所使用的拆除方法的影响(p = 0.73)。
对这三种拆除方法造成的牙釉质损伤的担忧是合理的。尽管这些方法被广泛使用,但寻找导致牙釉质损伤较小的方法是明智的。