Carrasco L D, Guerisoli D M Z, Rocha M J A, Pécora J D, Fröner I C
Ribeirão Preto Dental School, University of São Paulo, Ribeirão Preto, SP, Brazil.
Int Endod J. 2007 Mar;40(3):204-8. doi: 10.1111/j.1365-2591.2007.01216.x.
To evaluate ex vivo the efficacy of 35% hydrogen peroxide for intracoronal bleaching when activated by LEDs, halogen lamp or by the walking bleach technique.
Forty extracted human maxillary central incisors had their crowns resected 1 mm below the amelo-cemental junction and were submitted to artificial staining in centrifuged rat haemolysed blood. A 2-mm thick glass ionomer cervical plug was placed inside the canal, at the level of the amelo-cemental junction. Samples were divided randomly into five groups: group I received 35% hydrogen peroxide gel activated by LEDs. Group II received 35% hydrogen peroxide gel activated by a halogen lamp-based light curing unit. Group III received 35% hydrogen peroxide gel followed by the walking bleach technique. Group IV was neither artificially stained nor bleached (positive control) and group V was stained, but not bleached (negative control). The shade of the teeth was assessed visually by three independent and calibrated evaluators, before and after bleaching. The results were analysed using Kruskal-Wallis one-way analysis of variance and Dunn's post-test.
No statistical differences regarding sample shades were found amongst groups for the tested internal bleaching techniques (P > 0.05).
Hydrogen peroxide for intracoronal bleaching when activated either by LEDs, halogen lamp or by the walking bleach technique presented similar efficacy.
在体外评估35%过氧化氢在经发光二极管（LED）、卤素灯激活或采用内漂白技术时进行冠内漂白的效果。
40颗拔除的人上颌中切牙在釉牙骨质界下方1毫米处切除牙冠，并置于离心后的大鼠溶血血液中进行人工染色。在根管内釉牙骨质界水平放置一个2毫米厚的玻璃离子颈充填料。样本随机分为五组：第一组接受经LED激活的35%过氧化氢凝胶。第二组接受经卤素灯固化灯激活的35%过氧化氢凝胶。第三组接受35%过氧化氢凝胶，然后采用内漂白技术。第四组既不进行人工染色也不进行漂白（阳性对照），第五组进行染色但不进行漂白（阴性对照）。在漂白前后，由三名独立且经过校准的评估者通过视觉评估牙齿的颜色。结果采用Kruskal-Wallis单因素方差分析和邓恩事后检验进行分析。
在所测试的内漂白技术组之间，样本颜色没有统计学差异（P>0.05）。
35%过氧化氢在经LED、卤素灯激活或采用内漂白技术时进行冠内漂白，其效果相似。
