Kwon S R, Pallavi Fnu, Shi Y, Oyoyo U, Mohraz A, Li Y
Oper Dent. 2018 May/Jun;43(3):326-334. doi: 10.2341/17-099-L.
Whitening efficacy has been related to hydrogen peroxide (HP) diffusion into tooth structure. However, little information is available relating rheological properties to whitening efficacy. The purpose was to evaluate the whitening efficacy and HP penetration level of a 10% HP gel at three different viscosities and to compare them to a strip delivery system.
Extracted molars (n=120) were randomly assigned into five groups (n=24/ group): NC_MED (negative control; median): medium viscosity gel without HP; LOW: 10% HP gel (low viscosity experimental gel, Ultradent Products Inc); MED: 10% HP gel (medium viscosity experimental gel, Ultradent); HIGH: 10% HP gel (high viscosity gel, Ultradent); and CWS: Crest 3D Whitestrips 1-Hour Express (Procter & Gamble). All teeth were subjected to five 60-minute whitening sessions. Instrumental color measurements were performed at baseline (T), and 1-day after each application (T-T), and 1-month after whitening (T). HP penetration was estimated with leucocrystal violet and horseradish peroxidase. A Kruskal-Wallis test and post hoc Bonferroni test were performed to assess the difference in tooth color change and HP penetration among the groups (α=0.05).
Hydrogen peroxide penetration levels and overall color changes at T were 0.24 μg/mL / 2.80; 0.48 μg/mL / 8.48; 0.44 μg/mL / 7.72; 0.35 μg/mL / 8.49; 0.36 μg/mL / 7.30 for groups NC, LOW, MED, HIGH, and CWS, respectively. There was a significant difference for HP penetration, while there was no significant difference among the four experimental groups for tooth color change.
Rheological properties should be considered when developing new whitening formulations.
美白效果与过氧化氢（HP）向牙齿结构中的扩散有关。然而，关于流变学性质与美白效果之间的信息却很少。本研究旨在评估三种不同粘度的10% HP凝胶的美白效果和HP渗透水平，并将其与条带状给药系统进行比较。
将拔除的磨牙（n = 120）随机分为五组（n = 24/组）：NC_MED（阴性对照；中等粘度）：不含HP的中等粘度凝胶；LOW：10% HP凝胶（低粘度实验凝胶，Ultradent Products Inc）；MED：10% HP凝胶（中等粘度实验凝胶，Ultradent）；HIGH：10% HP凝胶（高粘度凝胶，Ultradent）；以及CWS：佳洁士3D炫白1小时快速美白牙贴（宝洁公司）。所有牙齿均接受五次60分钟的美白疗程。在基线（T）、每次应用后1天（T-T）和美白后1个月（T）进行仪器颜色测量。用无色结晶紫和辣根过氧化物酶评估HP渗透情况。进行Kruskal-Wallis检验和事后Bonferroni检验，以评估各组之间牙齿颜色变化和HP渗透的差异（α = 0.05）。
NC、LOW、MED、HIGH和CWS组在T时的过氧化氢渗透水平和总体颜色变化分别为0.24μg/mL / 2.80；0.48μg/mL / 8.48；0.44μg/mL / 7.72；0.35μg/mL / 8.49；以及0.36μg/mL / 7.30。HP渗透存在显著差异，而四个实验组在牙齿颜色变化方面无显著差异。
开发新的美白配方时应考虑流变学性质。
