Hamedi-Rad Fahimeh, Ghaffari Tahereh, Rezaii Farzad, Ramazani Ali
Assistant Professor, Department of Prosthodontist, Dental Faculty of Tabriz Medical Science University, Tabriz, Iran.
Dentist, Department of Georesources and Materials Engineering, University of Michigan-Ann Arbor.
J Dent (Tehran). 2014 Sep;11(5):495-505. Epub 2014 Sep 30.
Polymethyl methacrylate (PMMA), widely used as a prosthodontic base, has many disadvantages, including a high thermal expansion coefficient and low thermal conductivity, a low elasticity coefficient, low impact strength and low resistance to fatigue. This study aimed to make an in vitro comparison of the thermal conductivity, compressive strength, and tensile strength of the acrylic base of complete dentures with those of acrylic reinforced with nanosilver.
For this study, 36 specimens were prepared. The specimens were divided into three groups of 12; which were further divided into two subgroups of control (unmodified PMMA) and test (PMMA mixed with 5 weight% nanosilver).The results were analysed by Independent t-test.
This study showed that the mean thermal conductivity and compressive strength of PMMA reinforced with nanosilver were significantly higher than the unmodified PMMA (P<0.05), while the tensile strength decreased significantly after the incorporation of nanosilver (P<0.05).
Considering our results suggesting the favorable effect of silver nanoparticles on improving the thermal conductivity and compressive strength of PMMA, use of this material in the palatal area of maxillary acrylic resin dentures is recommended.
聚甲基丙烯酸甲酯(PMMA)作为一种广泛应用的义齿基托材料,存在诸多缺点,包括热膨胀系数高、热导率低、弹性系数低、冲击强度低以及抗疲劳性差。本研究旨在对全口义齿丙烯酸基托与纳米银增强丙烯酸基托的热导率、抗压强度和抗拉强度进行体外比较。
本研究制备了36个样本。样本被分为三组,每组12个;每组又进一步分为对照(未改性PMMA)和试验(PMMA与5重量%纳米银混合)两个亚组。结果采用独立t检验进行分析。
本研究表明,纳米银增强的PMMA的平均热导率和抗压强度显著高于未改性的PMMA(P<0.05),而加入纳米银后抗拉强度显著降低(P<0.05)。
鉴于我们的结果表明银纳米颗粒对提高PMMA的热导率和抗压强度有积极作用,建议在上颌丙烯酸树脂义齿的腭部区域使用该材料。