Dental Materials and Prosthodontics Department, São José dos Campos Dental School, Unesp, Univ Estadual Paulista, São José dos Campos, SP, Brazil.
Int Endod J. 2013 Jan;46(1):40-6. doi: 10.1111/j.1365-2591.2012.02090.x. Epub 2012 Jul 12.
To evaluate the effectiveness of ultrasonic activation of bleaching agents during ex vivo internal bleaching.
Fifty canine human teeth were artificially stained, root filled and divided into five groups (n = 10) that received SP - sodium perborate plus deionized water (control group), CP - 37% carbamide peroxide gel, CPUS - 37% carbamide peroxide gel plus ultrasonic application, HP - 35% hydrogen peroxide gel or HPUS - 35% hydrogen peroxide gel plus ultrasonic application. In groups CP and HP, the bleaching agent was left inside the pulp chamber for three applications of 10 min. In groups CPUS and HPUS, the same process was performed, but ultrasonic vibration was applied to the bleaching agent by an alloy tip for 30 s, with 30 s intervals. Two sessions were performed. The colour was measured initially and after each session by an intraoral dental spectrophotometer. The variation (Δ) of the colour parameters based on the CIELab system L*, a* and b*, and the colour alteration ΔE* were calculated after first and second section. Data were analysed by one-way anova and Tukey's test.
There was no significant difference amongst groups for ΔL*, Δa* and ΔE*, but there was a significant difference for Δb* in the first and second sessions (P = 0.0006 and 0.0016, respectively). After the first session, Δb* was significantly greater for groups HP and HPUS, without a significant difference between them. For the second session, group HPUS had the greatest Δb* values, but they were similar to groups HP and SP; group CP had the lowest values, which were similar to groups CPUS and SP.
Ultrasonic activation of bleaching agents during ex vivo internal bleaching was no more effective than conventional internal bleaching procedures, without activation.
评估在离体内部漂白过程中超声激活漂白剂的效果。
将 50 颗犬齿人工染色、根管填充并分为五组（n=10），分别接受 SP-过硼酸钠加去离子水（对照组）、CP-37%过氧化脲凝胶、CPUS-37%过氧化脲凝胶加超声应用、HP-35%过氧化氢凝胶或 HPUS-35%过氧化氢凝胶加超声应用。在 CP 和 HP 组中，将漂白剂留在牙髓腔内，进行三次每次 10 分钟的应用。在 CPUS 和 HPUS 组中，进行相同的过程，但用合金尖端向漂白剂施加 30 秒的超声振动，间隔 30 秒。进行两次疗程。用口腔内牙科分光光度计在初始和每次疗程后测量颜色。根据 CIELab 系统 L*、a和 b计算颜色参数的变化（Δ），并在第一次和第二次部分后计算颜色变化ΔE*。数据采用单因素方差分析和 Tukey 检验进行分析。
在第一次和第二次疗程中，各组之间的ΔL*、Δa和ΔE没有显著差异，但Δb有显著差异（P=0.0006 和 0.0016）。在第一次疗程后，HP 和 HPUS 组的Δb显著增加，两组之间无显著差异。在第二次疗程中，HPUS 组的Δb值最大，但与 HP 和 SP 组相似；CP 组的Δb值最低，与 CPUS 和 SP 组相似。
在离体内部漂白过程中，超声激活漂白剂并不比无激活的常规内部漂白程序更有效。
