Burgess J O, Alvarez A, Summitt J B
University of Texas Health Science Center at San Antonio, Dental School, Department of Restorative Dentistry 78284-7890, USA.
Oper Dent. 1997 May-Jun;22(3):128-32.
This study evaluated fracture resistance provided to complex amalgam restorations by adhesive and mechanical resistance features. The occlusal surfaces of 30 extracted molar teeth of similar size were ground flat to approximately 2 mm coronal to the CEJ. The teeth were divided into three groups. Roots were notched and embedded in acrylic resin. In two groups, four TMS Minim stainless steel pins were placed into dentin at the line angles. A copper band matrix was applied to each specimen and reinforced with compound. After applying either Copalite or Amalgambond Plus, Tytin amalgam was condensed into the matrix. The bands and excess amalgam were removed 10 minutes later, and each amalgam occlusal surface was ground flat to give the amalgam restoration a 4 mm occlusal height. Specimens were thermocycled for 2500 cycles at 6-60 degrees C with a 30-second dwell time. They were then stored in deionized water for 1 month at room temperature. A 1 mm 45 degrees bevel was placed on the facio-occlusal angle of the amalgam. Each specimen was loaded to failure in compression at 45 degrees in an Instron Testing Machine at a crosshead speed of 5 mm/min. The groups were: Group 1, four Minim pins and Copalite; Group 2, four Minim pins and Amalgambond Plus; and Group 3, Amalgambond Plus only. The data were analyzed using a one-factor ANOVA and a Tukey B post hoc test. There was no significant difference between Groups 1 and 3. The Amalgambond Plus combined with pins provided significantly greater resistance to fracture than pins or Amalgambond Plus alone (P < 0.05).
本研究评估了粘结和机械固位特征为复合银汞合金修复体提供的抗折性。将30颗大小相似的拔除磨牙的咬合面磨平，使其在牙骨质牙本质界（CEJ）冠方约2mm处。将牙齿分为三组。在牙根上刻痕并嵌入丙烯酸树脂中。在两组中，在牙本质的线角处放置4根TMS Minim不锈钢钉。给每个标本施加一个铜带成型片并用复合树脂加固。在应用Copalite或Amalgambond Plus后，将Tytin银汞合金填入成型片中。10分钟后移除成型片和多余的银汞合金，将每个银汞合金咬合面磨平，使银汞合金修复体具有4mm的咬合高度。标本在6 - 60摄氏度下进行2500次热循环，每次停留时间为30秒。然后在室温下于去离子水中储存1个月。在银汞合金的颊合角处制作一个1mm、45度的斜面。每个标本在Instron测试机中以45度角、5mm/min的十字头速度进行压缩加载直至破坏。分组如下：第1组，4根Minim钉和Copalite；第2组，4根Minim钉和Amalgambond Plus；第3组，仅使用Amalgambond Plus。使用单因素方差分析和Tukey B事后检验对数据进行分析。第1组和第3组之间无显著差异。与单独使用钉或Amalgambond Plus相比，Amalgambond Plus与钉联合使用提供了显著更高的抗折性（P < 0.05）。
