Teixeira Erica Cappelletto Nogueira, Hara Anderson Takeo, Turssi Cecilia Pedroso, Serra Mônica Campos
Department of Restorative Dentistry, Piracicaba School of Dentistry, State University of Campinas, São Paulo, Brazil.
J Adhes Dent. 2002 Winter;4(4):317-22.
This study evaluated the effect of nonvital tooth bleaching on shear bond strength (SBS) of the composite resin/bovine enamel interface at different periods of time after bleaching.
Three hundred twenty teeth were randomly divided into four groups according to bleaching agent: SPH: sodium perborate and 30% hydrogen peroxide; SPW: sodium perborate and distilled water; CP: 37% carbamide peroxide; and PLA: distilled water (placebo). The bleaching agents in the pulp chambers were replaced every 7 days for 4 weeks. For SBS testing, each of these groups was randomly divided into four subgroups (n = 20) according to the postbleaching periods of time: 0 (baseline), 7, 14, and 21 days. At the respective time, enamel slabs were embedded in polyester resin and flattened. Composite resin cylinders (Z100/Single bond, 3M) were bonded to the enamel surface and subjected to the SBS test using a universal testing machine.
The ANOVA and Tukey's test (alpha = 0.05) showed statistically significant differences (expressed by different letters) among the bleaching agents only at follows: PLA (a), CP (ab), SPW (ab), and SPH (b). The SPH group, showing the lowest mean value, differed significantly from the control group. At 7, 14, and 21 days, no significant differences were observed.
Nonvital tooth bleaching affected the resin/enamel SBS values when sodium perborate mixed with 30% hydrogen peroxide was used.
本研究评估了死髓牙漂白在漂白后不同时间段对复合树脂/牛牙釉质界面剪切粘结强度（SBS）的影响。
320颗牙齿根据漂白剂随机分为四组：SPH：过硼酸钠和30%过氧化氢；SPW：过硼酸钠和蒸馏水；CP：37%过氧化脲；PLA：蒸馏水（安慰剂）。髓腔内的漂白剂每7天更换一次，共4周。对于SBS测试，这些组中的每一组根据漂白后的时间段随机分为四个亚组（n = 20）：0（基线）、7、14和21天。在各自的时间，将牙釉质块嵌入聚酯树脂并磨平。将复合树脂圆柱体（Z100/单键，3M）粘结到牙釉质表面，并使用万能试验机进行SBS测试。
方差分析和Tukey检验（α = 0.05）显示，仅在以下方面，漂白剂之间存在统计学显著差异（用不同字母表示）：PLA（a）、CP（ab）、SPW（ab）和SPH（b）。显示最低平均值的SPH组与对照组有显著差异。在7、14和21天时，未观察到显著差异。
当使用过硼酸钠与30%过氧化氢混合时，死髓牙漂白会影响树脂/牙釉质的SBS值。
