Division of Removable Prosthodontics, Fukuoka Dental College, Fukuoka, Japan.
Acta Odontol Scand. 2012 Jul;70(4):297-302. doi: 10.3109/00016357.2011.600719. Epub 2011 Jul 27.
This study investigated the effect of thermal shock on the mechanical properties of injection-molded thermoplastic denture base resins.
Four thermoplastic resins (two polyamides, one polyethylene terephthalate, one polycarbonate) and, as a control, a conventional heat-polymerized polymethyl methacrylate (PMMA), were tested. Specimens of each denture base material were fabricated according to ISO 1567 and were either thermocycled or not thermocycled (n = 10). The flexural strength at the proportional limit (FS-PL), the elastic modulus and the Charpy impact strength of the denture base materials were estimated.
Thermocycling significantly decreased the FS-PL of one of the polyamides and the PMMA and it significantly increased the FS-PL of one of the polyamides. In addition, thermocycling significantly decreased the elastic modulus of one of the polyamides and significantly increased the elastic moduli of one of the polyamides, the polyethylene terephthalate, polycarbonate and PMMA. Thermocycling significantly decreased the impact strength of one of the polyamides and the polycarbonate.
The mechanical properties of injection-molded thermoplastic denture base resins changed after themocycling.
本研究旨在探讨热冲击对注塑热塑性义齿基托树脂力学性能的影响。
测试了四种热塑性树脂（两种聚酰胺、一种聚对苯二甲酸乙二醇酯、一种聚碳酸酯）和作为对照的传统热聚合聚甲基丙烯酸甲酯（PMMA）。根据 ISO 1567 标准制作了每种义齿基托材料的样本，并进行热循环或不热循环（n = 10）。估计了义齿基托材料的比例极限弯曲强度（FS-PL）、弹性模量和夏比冲击强度。
热循环显著降低了一种聚酰胺和 PMMA 的 FS-PL，并显著提高了一种聚酰胺的 FS-PL。此外，热循环显著降低了一种聚酰胺的弹性模量，并显著提高了一种聚酰胺、聚对苯二甲酸乙二醇酯、聚碳酸酯和 PMMA 的弹性模量。热循环显著降低了一种聚酰胺和聚碳酸酯的冲击强度。
注塑热塑性义齿基托树脂的力学性能在热循环后发生了变化。
