Consani Rafael Leonardo Xediek, Paula Andreia Bolzan de, Fugolin Ana Paula Piovezan, Pfeifer Carmem S
Prosthodontics and Periodontology Department, Piracicaba School of Dentistry, UNICAMP - Universidade Estadual de Campinas, Piracicaba, SP, Brazil.
Dental Materials Department, Piracicaba School of Dentistry, UNICAMP - Universidade Estadual de Campinas, Piracicaba, SP, Brazil.
Braz Dent J. 2020 Sep-Oct;31(5):523-531. doi: 10.1590/0103-6440202003772.
Thiourethane additives have been shown to improve properties in several dental polymer applications. The aim of this study was to verify the effect of the addition of thiourethane oligomers and acrylamide or isobornyl-based plasticizers on the physical properties of the denture base acrylic resin polymerized with microwaves. Thiourethane oligomer (TU) was synthetized and added to microwaved acrylic resin in proportions varying between 3 and 14 wt%. Separate experimental groups included the addition of dimethyl acrylamide (DMAM) and isobornyl methacrylate as plasticizers, at concentrations varying from 5 to 20 wt%. Samples were polymerized using microwave energy at 500 Watts for 3 min, deflasked at room temperature, stored in water at 37 °C for 24 h, and evaluated for: linear dimensional change, gloss, Knoop hardness, surface roughness, impact strength, yield strength, elastic modulus, toughness, yield strength, viscosity, glass transition temperature and network heterogeneity, and water sorption/solubility. Data were analyzed with ANOVA/Tukey's post-hoc test (a=5%). The addition of TU led to properties that were similar or worse than the materials to which it was not added, except for dimensional stability. The impact on properties was statistically significant for all materials above 20% addition of TU. The addition of DMAM at 5 wt% or isobornyl methacrylate at 10 wt% improved yield strength and modulus, but increased water sorption and solubility. Except for dimensional stability, the addition of thiourethane oligomers to acrylic denture base materials compromised most tested properties. The use of DMAM and isobornyl methacrylate improved properties for selected compositions.
硫脲烷添加剂已被证明可改善多种牙科聚合物应用中的性能。本研究的目的是验证添加硫脲烷低聚物和丙烯酰胺或异冰片基增塑剂对用微波聚合的义齿基托丙烯酸树脂物理性能的影响。合成了硫脲烷低聚物（TU），并以3至14 wt%之间变化的比例添加到微波丙烯酸树脂中。单独的实验组包括添加二甲基丙烯酰胺（DMAM）和甲基丙烯酸异冰片酯作为增塑剂，浓度在5至20 wt%之间变化。样品在500瓦的微波能量下聚合3分钟，在室温下脱模，在37°C的水中储存24小时，并评估以下指标：线性尺寸变化、光泽度、努氏硬度、表面粗糙度、冲击强度、屈服强度、弹性模量、韧性、屈服强度、粘度、玻璃化转变温度和网络不均匀性，以及吸水性/溶解性。数据采用方差分析/图基事后检验进行分析（α=5%）。除尺寸稳定性外，添加TU导致的性能与未添加的材料相似或更差。对于添加量超过20%的所有材料，对性能的影响具有统计学意义。添加5 wt%的DMAM或10 wt%的甲基丙烯酸异冰片酯可提高屈服强度和模量，但增加了吸水性和溶解性。除尺寸稳定性外，向丙烯酸义齿基托材料中添加硫脲烷低聚物会损害大多数测试性能。对于选定的组合物，使用DMAM和甲基丙烯酸异冰片酯可改善性能。
