Department of Reconstructive Sciences, School of Dental Medicine, University of Connecticut, Farmington, USA.
J Am Dent Assoc. 2012 Nov;143(11):1218-22. doi: 10.14219/jada.archive.2012.0067.
The author used a standardized technique to investigate the retentive properties of three resin-modified glass ionomer (RMGI) cements in the cementation of precious gold copings.
The author machined premolars on a jeweler's lathe to a taper of 16 ± 0.5 degrees. The occlusal table measured 4 millimeters. The author fabricated wax patterns with a uniform 360-degree internal fitting surface of 2.7 mm. Each group consisted of 10 samples. The author invested the wax patterns and cast them in gold. He cemented the copings as follows: group 1, RelyX Luting Plus (3M ESPE, St. Paul, Minn.); group 2, Fuji Plus Resin-Reinforced, Multipurpose Cement (GC America, Alsip, Ill.) and group 3, UltraCem Resin-Reinforced Glass Ionomer Cement (Ultradent Products, South Jordan, Utah). The author performed the cementation under controlled pressure. After 24 hours, he applied a tensile force until catastrophic failure (expressed as kilogram force at failure) occurred. The author used analysis of variance for statistical analysis (P < .05).
A statistically significant difference was demonstrated between UltraCem and the other two cements tested (P < .05), whereas no statistical difference could be demonstrated between RelyX and Fuji Plus (P > .05).
By using an established standardized ex vivo crown retention test, the author found that the three RMGI cements he tested generated retention values that were clinically desirable when compared with those of other commercially available cements that have been used successfully for many years. UltraCem scored the highest values, followed by Fuji Plus and RelyX, respectively.
Cementation of precious alloy crowns and bridges by using RMGI cements tested in this study generated retentive values that mostly exceeded those of conventional luting agents.
作者采用标准化技术研究了三种树脂改性玻璃离子（RMGI）水门汀在贵金属金冠粘结中的保持性能。
作者在珠宝车床机上加工前磨牙，锥度为 16±0.5 度。牙合面台宽 4 毫米。作者用均匀的 360 度内部适配面为 2.7 毫米的蜡型制作蜡型。每组包含 10 个样本。作者对蜡型进行包埋和铸造金冠。作者按如下方式粘结冠：第 1 组，RelyX 粘固剂（3M ESPE，明尼苏达州圣保罗）；第 2 组，Fuji Plus 树脂增强型多用途水门汀（GC America，伊利诺伊州艾尔西普）和第 3 组，UltraCem 树脂增强型玻璃离子水门汀（Ultradent Products，犹他州南乔丹）。作者在控制压力下进行粘结。24 小时后，施加拉力直至发生灾难性失效（以失效时的千克力表示）。作者进行了统计分析的方差分析（P<0.05）。
UltraCem 与所测试的其他两种水门汀之间存在统计学显著差异（P<0.05），而 RelyX 和 Fuji Plus 之间则无统计学差异（P>0.05）。
通过使用已建立的标准化体外冠固位测试，作者发现，与多年来成功使用的其他市售水门汀相比，他所测试的三种 RMGI 水门汀的固位值具有临床意义。UltraCem 的得分最高，其次是 Fuji Plus 和 RelyX。
使用本研究中测试的 RMGI 水门汀粘结贵金属合金冠和桥可产生的固位值大多超过传统的粘固剂。
