Sadeghian Saeid, Garavand Shirin, Davoudi Amin
Department of Orthodontics, School of Dentistry, Isfahan University of Medical Sciences, Isfahan, Iran.
Department of Orthodontics, School of Dentistry, Khorram Abad University of Medical Sciences, Khorram Abad, Iran.
J Orthod Sci. 2021 Jul 9;10:11. doi: 10.4103/jos.JOS_5_19. eCollection 2021.
Bleaching procedure can be companied before, during, or after orthodontic treatments. However, the risk of compromised bond strength of brackets to bleached enamels is in debate. This study tried to evaluate the shear bond strength (SBS) of bonded metal brackets to the previously bleached enamels.
In this study, 60 extracted, sound, human premolars were mounted vertically in cylindrical molds. The samples were randomly divided into four groups ( = 15): Control (C); at-home bleached by 20% carbamide peroxide (HB); in-office bleached by 45% carbamide peroxide (OB); and in-office bleached by 40% hydrogen peroxide activated with diode laser (L-OB). Sixty stainless steel brackets were bonded by no-primer adhesive resin (OrthoCem). Then SBS of bonded brackets was measured after 5000 thermal cycles at 5°C and 55°C. Finally, the collected data were analyzed by one-way ANOVA, and Tukey HSD tests by using SPPS software at a significant level of 0.05 ( = 0.05).
Group C showed significantly higher SBS values (all < 0.001); however, there were no significant differences in SBS compared to other tests' groups with each other (all > 0.05).
The SBS of bonded orthodontic brackets were compromised after bleaching with 20% and 40% of carbamide peroxide. Diode laser activation may not eliminate the negative effect of bleaching agents on SBS of bonded orthodontic brackets, neither.
漂白程序可在正畸治疗前、治疗期间或治疗后进行。然而，漂白后的牙釉质上托槽粘结强度受损的风险仍存在争议。本研究旨在评估金属托槽与先前漂白牙釉质之间的剪切粘结强度（SBS）。
本研究中，60颗拔除的、完好的人前磨牙垂直安装在圆柱形模具中。样本随机分为四组（每组n = 15）：对照组（C）；用20%过氧化脲在家漂白（HB）；用45%过氧化脲在诊所漂白（OB）；以及用40%过氧化氢经二极管激光激活在诊所漂白（L-OB）。60个不锈钢托槽用无底漆粘结树脂（OrthoCem）粘结。然后在5°C和55°C下经过5000次热循环后测量粘结托槽的SBS。最后，使用SPPS软件，采用单因素方差分析和Tukey HSD检验对收集的数据进行分析，显著性水平为0.05（α = 0.05）。
C组显示出显著更高的SBS值（所有P < 0.001）；然而，与其他测试组相比，SBS之间没有显著差异（所有P > 0.05）。
用20%和40%的过氧化脲漂白后正畸托槽的SBS会降低。二极管激光激活也可能无法消除漂白剂对正畸粘结托槽SBS的负面影响。
