Briso André Luiz Fraga, Gonçalves Rafael Simões, de Azevedo Fernanda Almeida, Gallinari Marjorie de Oliveira, dos Santos Paulo Henrique, Fagundes Ticiane Cestari
J Adhes Dent. 2015 Dec;17(6):529-34. doi: 10.3290/j.jad.a35250.
To quantify hydrogen peroxide (H2O2) penetration into restored bovine teeth subjected to whitening treatment.
Seventy-five enamel/dentin disks were divided into 5 groups (n = 15): intact disks (G1); cavity preparation only (G2); conventional adhesive system and composite resin (G3); resin-modified glass-ionomer cement (G4); and self-etching adhesive only (G5). After 24 h, the disks were placed into artificial pulp chambers containing an acetate buffer solution, and the first whitening session was performed using a 35% H2O2 (hydrogen peroxide) product. The disks were submitted to 10,000 thermal cycles and then stored for 1 year in deionized water. After this period, a second whitening session was performed. After each whitening procedure, the buffer solutions were analyzed for optical density in a spectrophotometer to assess the amount of H2O2 that had diffused. ANOVA and Tukey's test were used to compare the different groups and a Student's t-test was used to compare the different times (p ≤ 0.05).
Prior to aging, group 2 had the highest penetration of H2O2; the other groups showed similar, lower penetration. After thermocycling and aging, all groups showed a significant increase in H2O2 penetration. The greatest penetration of H2O2 into the pulp chamber was found in groups 2 and 5.
Aged restorations allowed greater H2O2 permeation through the tooth structure.
量化过氧化氢（H2O2）渗入经美白处理的修复牛牙的情况。
将75个釉质/牙本质盘分为5组（n = 15）：完整盘（G1）；仅制备洞形（G2）；传统粘结系统和复合树脂（G3）；树脂改性玻璃离子水门汀（G4）；以及仅自酸蚀粘结剂（G5）。24小时后，将这些盘放入含有醋酸盐缓冲溶液的人工牙髓腔中，并使用35%的H2O2（过氧化氢）产品进行首次美白疗程。这些盘经过10000次热循环，然后在去离子水中储存1年。在此期间后，进行第二次美白疗程。每次美白程序后，在分光光度计中分析缓冲溶液的光密度，以评估扩散的H2O2量。使用方差分析和Tukey检验比较不同组，使用学生t检验比较不同时间（p≤0.05）。
老化前，第2组H2O2的渗入率最高；其他组的渗入率较低且相似。经过热循环和老化后，所有组的H2O2渗入率均显著增加。在第2组和第5组中发现H2O2渗入牙髓腔的量最大。
老化的修复体使H2O2能更大程度地透过牙齿结构。
