Kamangar Sedighe Sadat Hashemi, Kiakojoori Kiana, Mirzaii Mansoore, Fard Mohammad Javad Kharazi
Assisstant Professor, Dental Research Center Dentistry Research Institute, Department of Operative Dentistry, Faculty of Dentistry, Tehran University of Medical Sciences, International Campus, Tehran, Iran.
Dental Student, Tehran University of Medical Sciences, International Campus, Tehran, Iran.
J Dent (Tehran). 2014 Mar;11(2):196-209. Epub 2014 Mar 31.
The aim of this study was to determine the effects of 40% hydrogen peroxide and 15% carbamide peroxide on microhardness and color change of a silorane-based composite resin in comparison with two methacrylate-based composites.
Fifty-four disc-shaped specimens (A3 shade) were fabricated of Filtek P90 (P90), Filtek Z350XT Enamel (Z350) and Filtek Z250 (Z250) (3MESPE) (n=18). The samples of each composite were randomly divided into three subgroups of 6. The control subgroups were immersed in distilled water; the test groups were exposed to Opalescence Boost (OB) once; and Opalescence PF (OP) (Ultradent) for two weeks. Vickers microhardness testing and a spectrophotometric analysis of the color of samples were performed before and after each intervention.
The baseline microhardness of P90 was significantly lower than that of the other two composites (P=0.001), but no difference was found between Z250 and Z350 in this respect (P=0.293). Bleaching treatments significantly decreased the microhardness of Z250 and Z350 (P< 0.001), but no change was observed in P90 test and control subgroups (P> 0.05). No significant difference was detected between the two types of bleaching (P>0.05). After bleaching with OB, ΔE value was measured to be 3.12(1.97), 3.31(1.84) and 3.7(2.11) for P90, Z250 and Z350, respectively. These values were 5.98(2.42), 4.66(2.85) and 4.90(2.78) after bleaching with OP with no significant difference.
Bleaching decreased the microhardness of methacrylate-based but not silorane-based composites. Although no significant differences were found in ΔE of composites, ΔE of all groups did not remain in the clinically acceptable range after bleaching except for P90 after bleaching with 40% H2O2 (ΔE < 3.3).
本研究旨在确定40%过氧化氢和15%过氧化脲与两种甲基丙烯酸酯基复合材料相比，对硅氧烷基复合树脂显微硬度和颜色变化的影响。
用Filtek P90（P90）、Filtek Z350XT Enamel（Z350）和Filtek Z250（Z250）（3MESPE）制作54个圆盘形试件（A3色）（n = 18）。每种复合材料的样本随机分为三个亚组，每组6个。对照组亚组浸泡在蒸馏水中；试验组分别用Opalescence Boost（OB）处理一次，用Opalescence PF（OP）（Ultradent）处理两周。在每次干预前后进行维氏显微硬度测试和样本颜色的分光光度分析。
P90的基线显微硬度显著低于其他两种复合材料（P = 0.001），但在这方面Z250和Z350之间未发现差异（P = 0.293）。漂白处理显著降低了Z250和Z350的显微硬度（P < 0.001），但P90试验组和对照组亚组未观察到变化（P > 0.05）。两种漂白方式之间未检测到显著差异（P > 0.05）。用OB漂白后，P90、Z250和Z350的ΔE值分别测得为3.12(1.97)、3.31(1.84)和3.7(2.11)。用OP漂白后，这些值分别为5.98(2.42)、4.66(2.85)和4.90(2.78)，无显著差异。
漂白降低了甲基丙烯酸酯基复合材料的显微硬度，但未降低硅氧烷基复合材料的显微硬度。尽管复合材料的ΔE未发现显著差异，但除40% H₂O₂漂白后的P90（ΔE < 3.3）外，所有组漂白后的ΔE均未保持在临床可接受范围内。
