Prabhakar A R, Thejokrishna P, Kurthukoti A J
Department of Pedodontics and Preventive Dentistry, Bapuji Dental College and Hospital, Davangere, India.
J Indian Soc Pedod Prev Dent. 2006 Sep;24(3):122-6. doi: 10.4103/0970-4388.27892.
The purpose of this study was to test the support to undermined occlusal enamel provided by posterior restorative composite (FiltekTM P60, 3M Dental products USA), polyacid modified resin composite (F2000 compomer, 3M Dental products, USA.), radiopaque silver alloy-glass ionomer cement (Miracle Mix. GC Corp, Tokyo, Japan) and Glass Ionomer cement (Fuji IX GP). To test each material, 20 human permanent mandibular third molars were selected. The lingual cusps were removed and the dentin supporting the facial cusps was cut away, leaving a shell of enamel. Each group of prepared teeth was restored using the materials according to the manufacturer's instructions. All the specimens were thermocycled (250 cycles, 6 degrees C- 60 degrees C, dwell time 30 seconds) and then mounted on an acrylic base. Specimens were loaded evenly across the cusp tips at a crosshead speed of 5 mm /minute in Hounsfield universal testing machine until fracture occurred. Data obtained was analyzed using analysis of variance and Studentized- Newman- Keul's range test. No significant differences were detected in the support provided by P-60, F 2000, Miracle Mix or Fuji IX GP groups. The support provided to undermined occlusal enamel by these materials was intermediate between no support and that provided by sound dentin. Without further development in dental material technology and evidence of its efficacy, restorative materials should not be relied upon to support undermined occlusal enamel to a level comparable to that provided by sound dentin.
本研究的目的是测试后牙修复用复合树脂（美国3M牙科产品公司的FiltekTM P60）、聚酸改性树脂复合体（美国3M牙科产品公司的F2000复合体）、不透射线的银合金玻璃离子水门汀（日本东京GC公司的Miracle Mix）和玻璃离子水门汀（富士IX GP）对牙合面釉质破坏区的支持作用。为测试每种材料，选取了20颗人类恒牙下颌第三磨牙。去除舌尖，并切除支持颊尖的牙本质，留下一层釉质壳。按照制造商的说明，使用这些材料对每组预备好的牙齿进行修复。所有标本进行热循环处理（250个循环，6℃ - 60℃，停留时间30秒），然后安装在丙烯酸基底上。在Hounsfield万能试验机上，以5毫米/分钟的十字头速度在牙尖顶端均匀加载标本，直至发生断裂。使用方差分析和Studentized - Newman - Keul's范围检验对获得的数据进行分析。在P - 60、F 2000、Miracle Mix或富士IX GP组提供的支持方面未检测到显著差异。这些材料对牙合面釉质破坏区提供的支持介于无支持和健康牙本质提供的支持之间。在牙科材料技术没有进一步发展及其有效性证据的情况下，不应依赖修复材料将牙合面釉质破坏区的支持水平提高到与健康牙本质相当的程度。
