Department of Restorative Dentistry, State University of Campibas, Brazil.
J Adhes Dent. 2011 Dec;13(6):537-42. doi: 10.3290/j.jad.a19813.
To evaluate the influence of bleaching on bond strength to enamel and subjacent dentin, and to determine whether a reduced application time (1 min) of the antioxidizing agent can obviate the compromised bond strength after bleaching.
One hundred twelve bovine incisors were obtained, and the enamel and dentin surfaces were standardized to a thickness of 1 mm. The specimens were divided into two control groups (enamel and dentin without treatment) and 12 experimental groups (n = 10), based on the concentration of bleaching agents (carbamide peroxide 16% and hydrogen peroxide 35%), time interval between bleaching and restorative procedures (24 h; 24 h + sodium ascorbate (SA) 10%/1 min; 14 days), and substrate (enamel or dentin). All samples were submitted to the bleaching treatment on enamel. After the stipulated interval, a microshear test was performed.
The bleaching treatment compromised the bond strength to the enamel when the restoration was performed 24 h after the end of bleaching. The bond strength to dentin was not affected by bleaching.
The SA 10% application for 1 min obviates the detrimental effect of bleaching on bond strength. The bleaching performed on enamel does not affect the bond strength to the subjacent dentin.
评估漂白对牙釉质和下方牙本质粘结强度的影响，并确定抗氧化剂应用时间（1 分钟）的减少是否可以避免漂白后粘结强度的降低。
从 112 颗牛切牙获得样本，将牙釉质和牙本质表面标准化至 1 毫米的厚度。根据漂白剂（过氧脲 16%和过氧化氢 35%）的浓度、漂白和修复程序之间的时间间隔（24 小时；24 小时+抗坏血酸钠 10%/1 分钟；14 天）以及基质（牙釉质或牙本质），将样本分为两个对照组（未经处理的牙釉质和牙本质）和 12 个实验组（n=10）。所有样本均在牙釉质上进行漂白处理。在规定的间隔时间后，进行微剪切试验。
漂白处理后 24 小时进行修复时，会降低牙釉质的粘结强度。漂白对牙本质的粘结强度没有影响。
抗坏血酸钠 10%应用 1 分钟可消除漂白对粘结强度的不利影响。在牙釉质上进行的漂白不会影响下方牙本质的粘结强度。
