Effect of bleaching on subsurface micro-hardness of composite and a polyacid modified composite
Effect of bleaching on subsurface micro-hardness of composite and a polyacid modified composite
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DOI：
10.1016/j.dental.2006.01.008
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发表时间：
2007-02-01
期刊：
影响因子：
5
通讯作者：
Attin, Thomas
中科院分区：
文献类型：
--
作者：
Hannig, Christian;Duong, Sebastian;Attin, Thomas
Objective.通过测定显微硬度，研究不同漂白工艺对复合材料和聚酸改性复合材料表面物理性能的影响。将Tetric Flow、Tetric EvoCeram和Compoglass的样本光固化（2.5mm厚度）并在人工唾液中储存2周（n =12/组）。仅在潮湿环境中应用以下漂白剂时取出样品：Vivastyle（1 h/d）、Whitestrips（30 min/d）、过硼酸钠-水混合物（一次，持续72 h）、Simply白色（1 h/d）或Opalescence XtraBoost（第1天和第5天，持续15 min）应用于样品表面。未处理的样本作为阴性对照，用乙醇处理1 h的样本作为阳性对照。漂白结束后，对试样进行横切，测定不同亚表层（0.1 mm ~ 2.0 mm）的显微硬度（Knoop）。与未处理的对照相比，所有漂白技术均显著降低了漂白剂的努氏硬度。因此，漂白显着影响不仅表面，而且深层的标本：在表层（0.1毫米，0.2毫米）的最低显微硬度值分别为69.5%和76.3%的未经处理的控制（Compoglass/Vivastyle）。在更深的次表面水平，观察到Opalescence/Tetric EvoCeram的硬度最低（0.3 mm：78.3%; 0.4 mm：80%; 0.5 mm：80.5%; 1.0 mm：84.2%; 2.0 mm：84.4%）。用测试的漂白剂漂白软化所检查的粘合剂修复材料。由于表面下层也会受到影响，表面抛光可能不足以重建填料表面的物理性质。(C)2006年，牙科材料学院。由爱思唯尔有限公司出版。保留所有权利。
Objective. To investigate the influence of different bleaching techniques on subsurface physical properties of composite and polyacid modified composite tested via determination of micro-hardness.Methods. Specimens of Tetric Flow, Tetric EvoCeram and Compoglass were light cured (2.5 mm thickness) and stored in artificial saliva for 2 weeks (n =12/group). The samples were only removed for application of the following bleaching agents in a humid atmosphere: Either Vivastyle (1 h/d), Whitestrips (30 min/d), sodium-perborate-water mixture (once for 72 h), Simply White (1 h/d), or Opalescence XtraBoost (1st and 5th day for 15 min) were applied on the surfaces of the samples. Untreated specimens served as negative controls, samples treated with ethyl alcohol for 1 h acted as positive controls. After the bleaching period, samples were cross-sectioned and the micro-hardness (Knoop) of different subsurface levels (0.1 mm-2.0 mm) was determined.Results. All bleaching techniques significantly reduced the Knoop-hardness of the restoratives compared to untreated controls. Thereby, bleaching significantly affected not only superficial but also the deep layers of the specimens: in superficial layers (0.1 mm, 0.2 mm) lowest micro-hardness values amounted to 69.5% and 76.3% of the respective untreated controls (Compoglass/Vivastyle). In deeper subsurface levels, the lowest hardness was observed with Opalescence/Tetric EvoCeram (0.3 mm: 78.3%; 0.4 mm: 80%; 0.5 mm: 80.5%; 1.0 mm: 84.2%; 2.0 mm: 84.4%).Significance. Bleaching with the tested bleaching agents softens the adhesive restorative materials examined. Due to the fact that subsurface layers are also affected, polishing of the surface may not suffice for re-establishing the physical properties of the surface of the fillings. (C) 2006 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.