Nejatidanesh Farahnaz, Momeni Glareh, Savabi Omid
Department of Prosthodontics and Torabinejad Dental Research Center, School of Dentistry, Isfahan University of Medical Sciences, Isfahan, Iran.
J Prosthodont. 2009 Aug;18(6):507-11. doi: 10.1111/j.1532-849X.2009.00473.x. Epub 2009 Jun 3.
Flexural strength of interim materials is of particular concern with long-span fixed partial dentures (FPDs) or in areas of heavy contact. The purpose of this study was to compare the flexural strength of seven resins used to fabricate interim fixed prostheses.
Ten identical 25 x 2 x 2 mm specimens were made from seven interim materials (N = 70) (Trim, Acropars, Protemp 3 Garant, Unifast LC, TempSpan, Tempron, Duralay) according to ADA specification #27. After 14 days' storage in artificial saliva and thermocycling for 2500 cycles (5 C to 55 C), a standard three-point bending test was conducted on the specimens with a universal testing machine at a crosshead speed of 0.75 mm/min. The mean values of flexural strength of each interim material were calculated. Data were analyzed using the Kruskal-Wallis and Mann-Whitney U-test, and the significance level was set at alpha= 0.05.
The lowest and highest flexural strengths were found for Trim from ethyl methacrylate resins and TempSpan from bis-acryl resins, respectively. The mean rank of flexural strength of the studied materials was TempSpan = 66.3, Protemp 3 Garant = 53.4, Tempron = 47.5, Duralay = 38.3, Unifast LC = 24.1, Acropars = 17.9, and Trim = 5.9. There was no significant difference between Tempron and Protemp 3 Garant, but the other resins were significantly different.
Bis-acryl interim materials exhibited higher flexural strength than the methacrylate resins tested in this study. These higher values should be considered in making interim fixed prostheses, especially when long-term use or long-span FPDs are planned.
对于长跨度固定局部义齿（FPD）或重度接触区域，临时材料的抗弯强度尤为重要。本研究的目的是比较用于制作临时固定修复体的七种树脂的抗弯强度。
根据ADA规范#27，用七种临时材料（N = 70）（Trim、Acropars、Protemp 3 Garant、Unifast LC、TempSpan、Tempron、Duralay）制作十个相同的25×2×2mm试样。在人工唾液中储存14天并进行2500次热循环（5℃至55℃）后，使用万能试验机以0.75mm/min的十字头速度对试样进行标准三点弯曲试验。计算每种临时材料的抗弯强度平均值。使用Kruskal-Wallis和Mann-Whitney U检验分析数据，显著性水平设定为α = 0.05。
甲基丙烯酸乙酯树脂类的Trim抗弯强度最低，双丙烯酸树脂类的TempSpan抗弯强度最高。所研究材料的抗弯强度平均秩次为TempSpan = 66.3，Protemp 3 Garant = 53.4，Tempron = 47.5，Duralay = 38.3，Unifast LC = 24.1，Acropars = 17.9，Trim = 5.9。Tempron和Protemp 3 Garant之间无显著差异，但其他树脂之间差异显著。
双丙烯酸类临时材料的抗弯强度高于本研究中测试的甲基丙烯酸树脂。在制作临时固定修复体时，尤其是计划长期使用或长跨度FPD时，应考虑这些较高的值。
