Arcari Gilberto Müller, Araújo Elito, Baratieri Luiz Narciso, Lopes Guilherme Carpena
Department of Operative Dentistry, Federal University of Santa Catarina, Florianopolis, SC, Brazil.
J Adhes Dent. 2007 Jun;9(3):333-40.
The purpose of this in vitro study was to measure the microtensile bond strength of a nanofilled composite resin to human dentin after nonvital bleaching at different post-bleaching time intervals, and to analyze the fracture mode under SEM.
Thirty-six sound human maxillary premolars extracted for orthodontic reasons were prepared in a standardized manner, and randomly assigned to four groups (n = 9): non bleached (control) (NB); bleached with sodium perborate and 35% hydrogen peroxide (SP-HP); bleached with 35% hydrogen peroxide (HP); and bleached with 37% carbamide peroxide (CP). Each group was subdivided into 3 subgroups (n = 3): restored immediately (RO); restored after 7 days (R7); and restored after 14 days (R14). The teeth were stored in distilled water for 24 h, sectioned 4 mm below cementoenamel junction, and the crown was serially sectioned to obtain sticks (0.9 mm2 cross section) for microtensile bond strength testing. The microTBS samples were attached to a universal testing machine (Instron, model 4444), using a Geraldeli's device. The test was performed until the fracture of the specimens, and all specimens were analyzed under a scanning electron microscope (Philips XL-30).
Two-way ANOVA (p = 0.05) revealed that there were no statistically significant differences of bond strength values for the bleaching agents used, or at different post-bleaching time intervals.
It was concluded that the definitive restoration can be accomplished immediately after nonvital bleaching treatment.
本体外研究的目的是测量纳米复合树脂在不同漂白后时间间隔进行非活髓漂白后与人类牙本质的微拉伸粘结强度，并在扫描电子显微镜下分析断裂模式。
选取36颗因正畸原因拔除的健康人上颌前磨牙，进行标准化制备，并随机分为四组（n = 9）：未漂白（对照组）（NB）；用硼酸钠和35%过氧化氢漂白（SP-HP）；用35%过氧化氢漂白（HP）；用37%过氧化脲漂白（CP）。每组再细分为3个亚组（n = 3）：立即修复（RO）；7天后修复（R7）；14天后修复（R14）。将牙齿在蒸馏水中储存24小时，在牙骨质釉质界下方4毫米处切片，将牙冠连续切片以获得用于微拉伸粘结强度测试的小棒（横截面为0.9平方毫米）。使用杰拉代利装置将微拉伸粘结强度测试样本连接到万能试验机（英斯特朗，型号4444）上。测试进行到样本断裂，所有样本在扫描电子显微镜（飞利浦XL-30）下进行分析。
双向方差分析（p = 0.05）显示，所用漂白剂或不同漂白后时间间隔的粘结强度值没有统计学上的显著差异。
得出的结论是，非活髓漂白治疗后可立即进行最终修复。
