Department of Prosthodontics, Dental School, National and Kapodistrian University of Athens, Athens, Greece.
Department of Operative Dentistry, Dental School, National and Kapodistrian University of Athens, Athens, Greece.
J Prosthodont. 2019 Jan;28(1):e89-e95. doi: 10.1111/jopr.12763. Epub 2018 Feb 22.
To evaluate the efficacy of a realistic staining/cleansing protocol for long-term prevention of discoloration of denture base resins.
Sixty discs (20 × 2.5 mm) of auto- and heat-polymerizing denture acrylic resins were fabricated following manufacturer's instructions, polished on one side and stored in water (37°C) for 24 hours before they were assigned randomly into 6 groups (3 for each material, n = 10) to receive 220 cycles of three immersion protocols. Group A was immersed in the following baths: (1) filtered coffee at 45°C for 2 minutes, (2) tap water at 24°C for 20 seconds, (3) as bath 1, (4) as bath 2, (5) Corega Extradent cleansing solution at 45°C for 3 minutes, and (6) water at 24°C for 20 seconds. Group B was immersed in the four first baths of group A (without cleansing action) and group C in bath 1 for the cumulative action of 20 cycles (80 minutes in 45°C coffee) and bath 2 for 40 seconds. A noncontact optical interferometric profilometer was used for qualitative evaluation of the specimens and a contact colorimeter to estimate color change values (ΔΕ*ab) at baseline and every 20 cycles in the baths for a total of 220 cycles. Data were statistically analyzed using a 2-way-repeated measures ANOVA with Bonferoni multiple comparisons and trend analysis at α = 0.05 level of significance.
Data indicated changes in color from 1.7 to 14.2 ΔΕ*ab units. The highest values were related to the number of cycles and group B immersion protocol. Significant differences were found among immersion protocols (p < 0.001) and immersion cycles (p < 0.001) with a significant interaction between protocols and cycles (p < 0.001) but not between denture resins (p = 0.991).
The evaluated protocol A was found effective in preventing color changes in both denture resins even after a long period of action. Protocol C had a much lower staining effect on both resins than protocol B and behaved similarly to protocol A until 140 to 160 cycles. Therefore, it is probably not appropriate for use in short-term color stability experiments.
评估一种现实的染色/清洁方案在长期预防义齿基托树脂变色方面的功效。
按照制造商的说明制作了 60 个（20×2.5 毫米）自凝和热凝义齿丙烯酸树脂圆盘，一侧抛光，在水（37°C）中储存 24 小时后，随机分为 6 组（每组 3 种材料，n=10），接受 220 个循环的三种浸泡方案。A 组浸泡在以下浴中：（1）45°C 的过滤咖啡浸泡 2 分钟，（2）24°C 的自来水浸泡 20 秒，（3）如浴 1，（4）如浴 2，（5）Corega Extradent 清洁液在 45°C 下浸泡 3 分钟，（6）24°C 的水浸泡 20 秒。B 组浸泡在 A 组的前四个浴中（没有清洁作用），C 组在 20 个循环（45°C 咖啡 80 分钟）时累计浸泡浴 1，在 40 秒时浸泡浴 2。使用非接触式光学干涉轮廓仪对样品进行定性评估，使用接触式比色计在基线和每个浴中每 20 个循环时估计颜色变化值（ΔΕ*ab），总共 220 个循环。使用双向重复测量方差分析，结合 Bonferoni 多重比较和 α=0.05 水平的趋势分析进行数据统计分析。
数据显示颜色从 1.7 到 14.2 ΔΕ*ab 单位发生变化。最高值与循环次数和 B 组浸泡方案有关。在浸泡方案（p<0.001）和浸泡循环（p<0.001）之间发现了显著差异，方案和循环之间存在显著的相互作用（p<0.001），但在义齿树脂之间没有（p=0.991）。
评估的方案 A 被发现即使在长时间作用后也能有效防止两种义齿树脂变色。方案 C 对两种树脂的染色效果比方案 B 低得多，在 140 到 160 个循环时与方案 A 表现相似。因此，它可能不适合用于短期颜色稳定性实验。
