Department of Fixed Prosthodontics, Faculty of Dentistry, Minia University, Giza, Egypt.
J Prosthodont. 2010 Jan;19(1):33-41. doi: 10.1111/j.1532-849X.2009.00519.x. Epub 2009 Sep 17.
To study the effect of bleaching agents on the surface topography of ceramometal alloys.
Three types of ceramometal alloys were used (gold, Ni-Cr, Co-Cr-Ti), and two types of bleaching agents (an agent intended for home use, one intended for use in the dental office) were studied. Forty-five specimens were constructed and divided according to the alloy type into three main groups, 15 specimens per group. Each group was further subdivided into three subgroups according to the type of bleaching agent used. The first subgroup (five specimens) was not subjected to any bleaching agent. The second and third subgroups were subjected to home and in-office bleaching agents, respectively.
Au alloy showed the least surface roughness when subjected to either of the two bleaching agents. Ni-Cr alloys showed the highest surface roughness for both the control and home bleached subgroups, and Co-Cr-Ti alloy showed the highest surface roughness in the in-office bleached subgroup. No statistically significant difference was found between the control subgroup and the home-bleached subgroup for either the Au alloy or the Co-Cr-Ti alloy. For the two alloys, both the control and home-bleached subgroups were statistically different from the in-office bleached subgroups. There was a statistically significant difference between the Ni-Cr control subgroup and the other two bleached subgroups, while there was no difference between the two bleached subgroups. Results also showed that increasing the concentration of bleaching agents increased the surface roughness of all the tested alloys. There was a statistical difference between the Ni-Cr alloy and the other two alloys in all tested subgroups except the in-office bleached subgroup, for which no difference between the surface roughness of the Ni-Cr alloy and the Co-Cr-Ti alloy was found. Scanning electron microscopic examination revealed surface deteriorations in the two bleached subgroups for all tested ceramometallic alloys.
Surface topographic alterations occurred as a result of the application of bleaching agents. These alterations increased with the increase of the carbamide peroxide concentration.
研究漂白剂对金瓷合金表面形貌的影响。
使用了三种金瓷合金（金、Ni-Cr、Co-Cr-Ti）和两种漂白剂（一种供家庭使用，一种供口腔诊室使用）进行研究。制作了 45 个样本，并根据合金类型将其分为三个主要组，每组 15 个样本。每个组根据使用的漂白剂类型进一步分为三个亚组。第一亚组（5 个样本）未使用任何漂白剂。第二和第三亚组分别使用家庭和诊室用漂白剂。
Au 合金在使用两种漂白剂时表现出最小的表面粗糙度。Ni-Cr 合金在对照和家庭漂白亚组中表现出最高的表面粗糙度，而 Co-Cr-Ti 合金在诊室漂白亚组中表现出最高的表面粗糙度。对于 Au 合金和 Co-Cr-Ti 合金，对照亚组与家庭漂白亚组之间没有统计学差异。对于这两种合金，对照亚组和家庭漂白亚组均与诊室漂白亚组之间存在统计学差异。Ni-Cr 对照亚组与其他两个漂白亚组之间存在统计学差异，而两个漂白亚组之间没有差异。结果还表明，随着漂白剂浓度的增加，所有测试合金的表面粗糙度都增加。在所有测试亚组中，除了诊室漂白亚组外，Ni-Cr 合金与其他两种合金之间均存在统计学差异，而在该亚组中，Ni-Cr 合金与 Co-Cr-Ti 合金的表面粗糙度没有差异。扫描电子显微镜检查显示，所有测试的金瓷合金在两个漂白亚组中均出现表面恶化。
由于应用漂白剂，表面形貌发生了改变。这些变化随着过氧化脲浓度的增加而增加。
