The study aimed to compare the effectiveness of an experimental gel that contained 6% hydrogen peroxide, titanium dioxide (TiO₂), and chitosan nanoparticles with that of the two bleaching agents that are routinely used and evaluate their effectiveness in a 3‐month period. Seventy‐two extracted premolar teeth were divided into three groups for the bleaching procedure. TiO₂ and chitosan were added to increase the whitening effect of the low‐concentration experimental gel. In group 1, the experimental gel was applied and activated with a D‐Light Duo LED device. In group 2, Opalescence Boost PF was applied chemically. In group 3, Philips Zoom was applied and activated with Zoom Advanced Power. The color of the teeth was measured with a Vita Easyshade Advance 4.0 spectrophotometer before the bleaching and 24 hours, 7 days, 14 days, 30 days, and 3 months after final bleaching. The CIEDE2000 color differences (∆E₀₀) and average L*, a*, and b* values were calculated. Effective bleaching was observed in three groups as determined by the initial color at different measurement times (P < .05). Philips Zoom showed a higher value of color change than the other groups at all times. The experimental gel showed a bleaching activity like that of Opalescence Boost PF at all‐time measurements. A slight decrease in color change was observed between the first‐month measurement and third‐month measurement in all groups. A low‐concentration experimental gel containing TiO₂ and chitosan provided effective whitening, and the whitened color persisted throughout the 3‐month period.

中文翻译：

---

含Tio2和壳聚糖的低浓度（6％过氧化氢）实验漂白凝胶的三个月评估：一项体外研究

该研究旨在比较含有6％过氧化氢，二氧化钛（TiO ₂）和壳聚糖纳米粒子的实验凝胶与常规使用的两种漂白剂的功效，并评估其在3个月内的功效。将72颗拔除的前磨牙分为三组进行漂白。二氧化钛₂添加了壳聚糖和壳聚糖以提高低浓度实验凝胶的增白效果。在第1组中，应用了实验凝胶，并用D‐Light Duo LED设备激活。在第2组中，化学应用Opalescence Boost PF。在第3组中，飞利浦Zoom被应用并通过Zoom Advanced Power激活。在漂白之前以及在最终漂白之后的24小时，7天，14天，30天和3个月之前，使用Vita Easyshade Advance 4.0分光光度计测量牙齿的颜色。计算出CIEDE2000的色差（∆ E ₀₀）和平均L *，a *和b *值。根据不同测量时间下的初始颜色确定，三组有效漂白（P <.05）。飞利浦Zoom始终显示出比其他组更高的颜色变化值。实验凝胶在所有时间都显示出像Opalescence Boost PF一样的漂白活性。在所有组的第一个月测量和第三个月测量之间，观察到颜色变化略有减少。含有TiO ₂和壳聚糖的低浓度实验凝胶可以有效地增白，并且在整个3个月的时间内仍保持增白的颜色。