UNASSIGNED: Sixty extracted single-rooted maxillary incisors postdecoronation, keeping their labial surfaces up were mounted in cold-cure acrylic resin. The samples were randomly divided into: Group I - unbleached; Group II - 10% pine bark extract for 10 min postbleaching; Group III - 10% pine bark extract for 20 min postbleaching; Group IV - application of 10% rosemary extract for 10 min postbleaching, Group V - application of 10% rosemary extract for 20 min postbleaching; Group VI - no application of antioxidant. 35% hydrogen peroxide was used for bleaching all the samples except those which served as negative control. Later composite cylinder 4 mm in diameter and length were built on prepared enamel. The maximum load at failure was recorded using the universal testing machine.
UNASSIGNED: Data were analyzed using the analysis of variance and Tukey\'s t-test with significance level of P < 0.05.
UNASSIGNED: Highest load was exhibited by Group I. Group V showed satisfactory shear strength followed by Groups IV, III, II, and VI.
UNASSIGNED: Both 10% rosemary and 10% pine bark extracts showed better results when applied for 20 min as compared to 10 min application. Increased duration of antioxidant application increases the SBS.
■60个拔除单根上颌切牙后装饰,保持阴唇表面向上安装在冷固化丙烯酸树脂中。将样品随机分为:I组-未漂白;II组-10%松树皮提取物漂白后10分钟;III组-10%松树皮提取物漂白后20分钟;IV组-应用10%迷迭香提取物漂白后10分钟,组V-应用10%迷迭香提取物20分钟后漂白;组VI-不应用抗氧化剂。35%过氧化氢用于漂白除了用作阴性对照的那些样品之外的所有样品。后来在制备的搪瓷上构建直径和长度为4mm的复合圆柱体。使用万能试验机记录失效时的最大载荷。
■数据分析采用方差分析和Tukeyt检验,显著性水平为P<0.05。
■第一组表现出最高的载荷。第五组表现出令人满意的剪切强度,然后是第四组,III,II,和VI。
当施用20分钟时,与施用10分钟相比,10%迷迭香和10%松树皮提取物均显示出更好的结果。增加抗氧化剂施用的持续时间增加SBS。