Moradinezhad Mehrnaz, Moradi Mina, Shamohammadi Milad, Hormozi Elham, Ghorani Amir
Department of Orthodontics, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran.
Department of Orthodontics, School of Dentistry, North Khorasan University of Medical Sciences, Bojnurd, Iran.
Dent Res J (Isfahan). 2018 May-Jun;15(3):180-184.
By increasing the number of adults seeking orthodontic treatment bonding orthodontic brackets to the surfaces other than intact enamel has become necessary. The purpose of this study was to evaluate the effect of three different surface preparation methods associated with orthodontic bonding on porcelain color alteration.
In this study forty-five porcelain discs (6- mm diameter, 2- mm thickness) were fabricated. The color of the specimens was evaluated by means of a Vita Easyshade. Commision Internationale de I'Eclairage (CIE) L* a* b* system was used for color measurement. Then, the specimens were randomly divided into three groups ( = 15) with respect to the surface preparation methods including a 9.6% hydrofluoric acid (HF) + silane, sandblasting, and sandblasting + 9.6% HF + silane. Metal orthodontic brackets were bonded. Samples were stored in 37° c water for 24 hours. Afterward, the brackets were debonded with a debonding plier and porcelain surfaces were polished with a tungsten-carbide bur. The color assessment was done, and ΔE values were measured. ΔE = 3.7 units were considered as an acceptability threshold. Data were analyzed with Paired -test and one-way ANOVA. Level of significance was set at < 0.05.
Orthodontic bonding changed the color parameters significantly. Mean L*, a* and b* difference were 1.35 ± 2.41, 0.19 ± 0.80, 0.89 ± 1.27 units, respectively ( = 0.003 for L*, < 0.001 for a* and b*). There was not any significant difference in ΔE units between the groups ( = 0.456). In all the groups the mean ΔE values were below 3.7 units and within the clinically acceptable limit.
Orthodontic treatment changed the CIE color parameters of porcelain surface. However, the color alteration is below the clinically acceptable threshold. With regard to color alteration, there is no difference between different surface conditioning methods.
随着寻求正畸治疗的成年人数量增加，将正畸托槽粘结在完整牙釉质以外的表面已成为必要。本研究的目的是评估与正畸粘结相关的三种不同表面处理方法对瓷颜色改变的影响。
本研究制作了45个瓷盘（直径6毫米，厚度2毫米）。通过Vita Easyshade评估标本的颜色。采用国际照明委员会（CIE）Lab*系统进行颜色测量。然后，根据表面处理方法将标本随机分为三组（每组n = 15），包括9.6%氢氟酸（HF）+硅烷、喷砂以及喷砂+ 9.6% HF +硅烷。粘结金属正畸托槽。样本在37℃水中储存24小时。之后，用去粘结钳取下托槽，并用碳化钨车针打磨瓷表面。进行颜色评估并测量ΔE值。ΔE = 3.7单位被视为可接受阈值。数据采用配对t检验和单因素方差分析进行分析。显著性水平设定为P < 0.05。
正畸粘结显著改变了颜色参数。平均L*、a和b差值分别为1.35±2.41、0.19±0.80、0.89±1.27单位（L的P = 0.003，a和b*的P < 0.001）。各组之间的ΔE单位没有显著差异（P = 0.456）。在所有组中，平均ΔE值均低于3.7单位，在临床可接受范围内。
正畸治疗改变了瓷表面的CIE颜色参数。然而，颜色改变低于临床可接受阈值。就颜色改变而言，不同的表面处理方法之间没有差异。
