Najjar Yasser Munther, Burhan Ahmad S, Hajeer Mohammad Y, Nawaya Fehmieh R
Department of Orthodontics, University of Damascus Dental School, Damascus, Syria.
Department of Orthodontics, University of Damascus Dental School, Damascus, Syria.
Int Orthod. 2023 Mar;21(1):100718. doi: 10.1016/j.ortho.2022.100718. Epub 2022 Dec 12.
This study aimed to evaluate microleakage beneath metal brackets cured by different light curing modes.
Sixty extracted human premolars were randomly divided into three groups according to the light curing mode. Metal brackets were bonded in all groups according to the manufacturer's recommendations with a light-emitting diode device. Light curing was applied as follows: group 1: conventional mode (10 s mesial+10 s distal); group 2: soft start mode (15 s mesial+15 s distal); group 3: pulse delay mode (3 s mesial+3 s distal, followed by 3min of no photoactivation, then 9 s mesial+9 s distal). Radiant exposure was the same in all study groups. After curing, the teeth were incubated at 37 degrees for 24hours, then thermocycled 500 times. Next, they were sealed with nail varnish, immersed in methylene blue 1% for 24hours, sectioned, and examined under a stereomicroscope. Microleakage was measured at both enamel-adhesive and bracket-adhesive interfaces, and the total microleakage for each tooth was computed. Statistical analyses were performed using Kruskal-Wallis and Welch test for comparing microleakage among groups. Wilcoxon signed ranks test was used for comparing microleakage between the bracket-adhesive and enamel-adhesive interfaces.
There was no significant difference in microleakage at the bracket-adhesive interface among study groups. At the enamel-adhesive interface and total microleakage, the pulse delay group exhibited significantly lower microleakage than the conventional group. Whereas there was no significant difference between the soft start group and other study groups. In all study groups, microleakage at the enamel-adhesive interface was greater than that at the bracket-adhesive interface.
The pulse delay mode caused lesser microleakage than the conventional mode. This supports the use of this mode in orthodontic bonding.
本研究旨在评估不同光固化模式下金属托槽下方的微渗漏情况。
60颗拔除的人类前磨牙根据光固化模式随机分为三组。按照制造商的建议，使用发光二极管装置在所有组中粘结金属托槽。光固化应用如下：第1组：传统模式（近中10秒+远中10秒）；第2组：软启动模式（近中15秒+远中15秒）；第3组：脉冲延迟模式（近中3秒+远中3秒，随后3分钟无光激活，然后近中9秒+远中9秒）。所有研究组的辐射暴露相同。固化后，牙齿在37度下孵育24小时，然后进行500次热循环。接下来，用指甲油密封，浸入1%的亚甲蓝中24小时，切片，并在体视显微镜下检查。在釉质-粘结剂和托槽-粘结剂界面测量微渗漏，并计算每颗牙齿的总微渗漏。使用Kruskal-Wallis和Welch检验进行统计分析，以比较组间微渗漏情况。使用Wilcoxon符号秩检验比较托槽-粘结剂和釉质-粘结剂界面之间的微渗漏情况。
研究组之间托槽-粘结剂界面的微渗漏无显著差异。在釉质-粘结剂界面和总微渗漏方面，脉冲延迟组的微渗漏明显低于传统组。而软启动组与其他研究组之间无显著差异。在所有研究组中，釉质-粘结剂界面的微渗漏大于托槽-粘结剂界面的微渗漏。
脉冲延迟模式比传统模式引起的微渗漏更少。这支持在正畸粘结中使用该模式。
