Department of Dental Materials and Prosthodontics, Araçatuba Dental School, Sao Paulo State University, José Bonifácio, 1193, Araçatuba, Sao Paulo 16015-050, Brazil.
J Prosthodont Res. 2010 Jul;54(3):123-7. doi: 10.1016/j.jpor.2009.12.001. Epub 2010 Jan 17.
This study aimed to evaluate the effect of different storage periods in artificial saliva and thermal cycling on Knoop hardness of 8 commercial brands of resin denture teeth.
Eigth different brands of resin denture teeth were evaluated (Artplus group, Biolux group, Biotone IPN group, Myerson group, SR Orthosit group, Trilux group, Trubyte Biotone group, and Vipi Dent Plus group). Twenty-four teeth of each brand had their occlusal surfaces ground flat and were embedded in autopolymerized acrylic resin. After polishing, the teeth were submitted to different conditions: (1) immersion in distilled water at 37+/-2 degrees C for 48+/-2h (control); (2) storage in artificial saliva at 37+/-2 degrees C for 15, 30 and 60 days, and (3) thermal cycling between 5 and 55 degrees C with 30-s dwell times for 5000 cycles. Knoop hardness test was performed after each condition. Data were analyzed with two-way ANOVA and Tukey's test (alpha=.05).
In general, SR Orthosit group presented the highest statistically significant Knoop hardness value while Myerson group exhibited the smallest statistically significant mean (P<.05) in the control period, after thermal cycling, and after all storage periods. The Knoop hardness means obtained before thermal cycling procedure (20.34+/-4.45 KHN) were statistically higher than those reached after thermal cycling (19.77+/-4.13 KHN). All brands of resin denture teeth were significantly softened after storage period in artificial saliva.
Storage in saliva and thermal cycling significantly reduced the Knoop hardness of the resin denture teeth. SR Orthosit denture teeth showed the highest Knoop hardness values regardless the condition tested.
本研究旨在评估在人工唾液和热循环中不同储存时间对 8 种商用树脂义齿的科氏硬度的影响。
评估了 8 种不同品牌的树脂义齿（Artplus 组、Biolux 组、Biotone IPN 组、Myerson 组、SR Orthosit 组、Trilux 组、Trubyte Biotone 组和 Vipi Dent Plus 组）。每个品牌的 24 颗牙齿的咬合面被磨平并嵌入自聚合丙烯酸树脂中。抛光后，这些牙齿经历了以下不同条件：（1）在 37+/-2°C 的蒸馏水中浸泡 48+/-2 小时（对照）；（2）在 37+/-2°C 的人工唾液中储存 15、30 和 60 天；（3）在 5 至 55°C 之间进行热循环，每个循环 5000 次，每次停留 30 秒。在每个条件下都进行科氏硬度测试。使用双向方差分析和 Tukey 检验（α=.05）对数据进行分析。
总体而言，SR Orthosit 组在对照期、热循环后和所有储存期后表现出最高的科氏硬度值，而 Myerson 组表现出最小的科氏硬度值（P<.05）。在热循环程序之前获得的科氏硬度平均值（20.34+/-4.45 KHN）明显高于热循环后获得的科氏硬度平均值（19.77+/-4.13 KHN）。所有品牌的树脂义齿在人工唾液储存后均明显软化。
在唾液中储存和热循环显著降低了树脂义齿的科氏硬度。无论测试条件如何，SR Orthosit 义齿的科氏硬度值均最高。
