Feiz A, Khoroushi M, Gheisarifar M
Assistant Professor, Department of Operative Dentistry, Faculty of Dentistry and Professor Torabinejad Dental Research Center, Isfahan University of Medical Sciences, Isfahan, Iran.
J Dent (Tehran). 2011 Spring;8(2):60-6. Epub 2011 Jun 30.
Application of sodium ascorbate as an antioxidant and calcium hydroxide as a buffering agent following intracoronal bleaching has been recommended. The aim of this study was to investigate the effect of using the mentioned materials on shear bond strength of composite resin to the bleached dentin.
In this in vitro investigation, sixty human sound premolars were divided randomly into five groups (n=12). Occlusal dentin surfaces were exposed. The negative control (NC) group was not bleached and the other groups were bleached with 35% hydrogen peroxide gel for 5 days. Afterwards, composite cylinders were built up in the positive control (PC) group immediately after bleaching, in the delay bonding (DB) group after one week, in the sodium ascorbate (SA) and calcium hydroxide (CH) groups after 40 hours of treatment with the materials. Then, the samples were stored in 37°C for 24 hours. The specimens were thermocycled (5-55°C, 500 cycles), subjected to shear bond testing by universal machine. The data were analyzed by One-Way ANOVA and Duncan tests (α =0.05).
There was a significant difference between PC and CH groups in comparison with the other groups (p<0.05), but the difference among other groups was not significant (p>0.05).
Application of sodium ascorbate could significantly increase the bond strength of composite resin to bleached dentin, while the use of calcium hydroxide did not affect bond strength.
有人建议在冠内漂白后应用抗坏血酸钠作为抗氧化剂，氢氧化钙作为缓冲剂。本研究的目的是探讨使用上述材料对复合树脂与漂白牙本质之间剪切粘结强度的影响。
在这项体外研究中，60颗健康的人类前磨牙被随机分为五组（n = 12）。暴露咬合面牙本质表面。阴性对照组（NC）不进行漂白，其他组用35%过氧化氢凝胶漂白5天。之后，阳性对照组（PC）在漂白后立即构建复合树脂圆柱体，延迟粘结组（DB）在一周后构建，抗坏血酸钠（SA）组和氢氧化钙（CH）组在用材料处理40小时后构建。然后，将样本在37°C下储存24小时。对样本进行热循环（5 - 55°C，500次循环），通过万能机进行剪切粘结测试。数据采用单因素方差分析和邓肯检验进行分析（α = 0.05）。
与其他组相比，PC组和CH组之间存在显著差异（p < 0.05），但其他组之间的差异不显著（p > 0.05）。
应用抗坏血酸钠可显著提高复合树脂与漂白牙本质的粘结强度，而使用氢氧化钙对粘结强度没有影响。
