Department of Dental Materials and Prosthodontics, Ribeirão Preto School of Dentistry, Ribeirao Preto, Brazil.
J Prosthodont. 2010 Jan;19(1):52-7. doi: 10.1111/j.1532-849X.2009.00522.x. Epub 2009 Sep 23.
The aim of this study was to evaluate the color stability, surface roughness, and surface porosity of acrylic resins for eye sclera polymerized by different heat sources and submitted to accelerated artificial aging (AAA).
Three groups of ten specimens each were formed according to the heat source used during the polymerization cycle: GI-short cycle, GII-long cycle, and GIII-dry-heat oven. The groups were submitted to color spectrophotometry through the CIE L a b system and to surface roughness and porosity analysis using a Surfcorder IF 1700 profilometer. After the tests, specimens were submitted to AAA, with a maximum aging time of 384 hours, corresponding to a year of clinical use. After aging, the color and roughness of each group were assessed.
The results showed that the variability of DeltaE was clinically unacceptable for all groups but the method of polymerization was insignificant (p > 0.05) for color change. For roughness, polymerization cycle was significant for the results. GIII (0.23 +/- 0.06) presented the highest roughness difference (before and after AAA), statistically significant (p < 0.05) from GII. No statistically significant difference could be found among groups when considering the porosity test.
It may be concluded that irrespective of the type of heat used for polymerization, there was an intense color alteration, to clinically unacceptable levels, when the specimens were submitted to AAA. For the other properties, alterations were less intense.
本研究旨在评估不同热源聚合的丙烯酸树脂的颜色稳定性、表面粗糙度和表面孔隙率，并对其进行加速人工老化（AAA）处理。
根据聚合循环中使用的热源，将每组 10 个样本分为三组：GI-短周期、GII-长周期和 GIII-干热烤箱。通过 CIE L a b 系统对各组进行比色分光光度测定，并使用 Surfcorder IF 1700 轮廓仪进行表面粗糙度和孔隙率分析。测试后，将样本进行 AAA 处理，最大老化时间为 384 小时，相当于临床使用一年。老化后，评估每组的颜色和粗糙度。
结果显示，所有组别的 DeltaE 变化均具有临床不可接受的变异性，但聚合方法对颜色变化无显著影响（p > 0.05）。对于粗糙度，聚合循环对结果有显著影响。GIII（0.23 +/- 0.06）的粗糙度差异最大（AAA 前后），与 GII 相比具有统计学意义（p < 0.05）。在考虑孔隙率测试时，各组之间未发现统计学差异。
无论聚合使用哪种热源，样本进行 AAA 处理后，颜色变化明显，达到临床不可接受的程度。对于其他性能，变化不太明显。
