Gökay O, Ziraman F, Cali Asal A, Saka O M
Department of Restorative Dentistry, Faculty of Dentistry, University of Ankara, Ankara, Turkey.
Int Endod J. 2008 Jul;41(7):556-60. doi: 10.1111/j.1365-2591.2008.01384.x. Epub 2008 Mar 18.
To evaluate and compare radicular peroxide diffusion from different concentrations of carbamide peroxide bleaching gels. METHODOLOGY; Fifty maxillary premolar teeth were separated into five groups (n = 10). Standardized endodontic access cavities were prepared in the occlusal surfaces, and the root canals were prepared using a step back technique and filled using the lateral compaction technique. The gutta-percha filling was removed 4 mm short of the cemento-enamel junction (CEJ) and a 2-mm-thick glass-ionomer cement base was placed. Outer root surfaces were sealed with wax and nail polish, leaving the coronal third of the tooth and the CEJ exposed. All teeth were immersed in a plastic tube containing 2 mL of distilled water, and the experimental groups were treated with a bleaching agent of either 10%, 17% or 37% carbamide peroxide (CP) or a mixture of 30% hydrogen peroxide (HP) and sodium perborate (SP) placed into the coronal pulp chamber of teeth and left for 24 h. Peroxide penetration was measured using the ferrothiocyanate method. Statistical analysis of data was conducted by using the Kruskal-Wallis Analysis of Variance and Mann-Whitney U test.
Higher peroxide penetration occurred with the 30% HP-SP mixture than with the CP bleaching gels, and the 37% CP group also promoted greater peroxide penetration than the other CP groups (P < 0.05). There was no statistically significant difference between 10% and 17% CP groups (P > 0.05).
Peroxide penetration of CP gels was significantly lower than that of a HP-SP mixture.
评估并比较不同浓度过氧化脲漂白凝胶的根管内过氧化物扩散情况。方法：50颗上颌前磨牙被分为五组（每组n = 10）。在牙合面制备标准化的根管入口洞形，采用逐步后退技术预备根管并使用侧向加压技术充填。将牙胶充填物从牙骨质-釉质界（CEJ）处截短4 mm，并放置一层2 mm厚的玻璃离子水门汀基底。用蜡和指甲油封闭牙根外表面，使牙冠的三分之一和CEJ暴露。所有牙齿均浸泡在装有2 mL蒸馏水的塑料管中，实验组分别用10%、17%或37%的过氧化脲（CP）漂白剂或30%过氧化氢（HP）与过硼酸钠（SP）的混合物置于牙冠髓腔中24小时。采用硫氰酸铁法测量过氧化物的渗透情况。使用Kruskal-Wallis方差分析和Mann-Whitney U检验对数据进行统计学分析。
30% HP-SP混合物的过氧化物渗透高于CP漂白凝胶，37% CP组的过氧化物渗透也高于其他CP组（P < 0.05）。10%和17% CP组之间无统计学显著差异（P > 0.05）。
CP凝胶的过氧化物渗透显著低于HP-SP混合物。
