Dimensional change over time of extended-storage alginate impression materials.
Dimensional change over time of extended-storage alginate impression materials.
复制标题
长期储存藻酸盐印模材料的尺寸随时间的变化。
DOI：
10.2319/031510-150.1
复制
发表时间：
2010
期刊：
影响因子：
--
通讯作者：
K. Williams
中科院分区：
文献类型：
--
作者：
M. Walker;J. Burckhard;David A Mitts;K. Williams
目标
评价两种长期保存藻酸盐印模材料随时间的尺寸变化。
方法
根据ADA规范第18号，使用三种藻酸盐（两种延长储存的藻酸盐和一种常规藻酸盐），用不锈钢模具制造密封件。印模储存30分钟、48小时或100小时（n = 10个印模/材料/储存时间）。在相应的储存时间之后，通过比较型腔中的中间水平线与模具上的相同线的长度并计算差异百分比来测量尺寸变化。
结果
随着时间的推移，材料之间的尺寸变化存在显著差异（P <0.05）。所有材料在30分钟后都表现出收缩，常规藻酸盐随时间继续收缩，而延长储存的藻酸盐随着储存时间的增加而膨胀。传统的藻酸盐在30分钟后是最准确的。相比之下，一种延长储存的藻酸盐在所有储存时间都表现出最小的尺寸变化，另一种在储存100小时后最准确。
结论
有证据表明，牙科石膏的延迟浇注不会对使用两种长期储存的藻酸盐生成的铸件的尺寸精度产生不利影响。然而，只有一种延长储存材料似乎适合于短期和延长储存应用。
OBJECTIVES
To evaluate the dimensional change over time of two extended-storage alginate impression materials.
METHODS
Impressions were made of stainless steel dies in accordance with ADA Specification No. 18 using three alginates: two extended-storage alginates and one conventional alginate. The impressions were stored for 30 minutes, 48 hours, or 100 hours (n = 10 impressions/material/storage time). Following the respective storage times, dimensional change was measured by comparing the length of the middle horizontal line in the impression with the same line on the die and computing percent difference.
RESULTS
Significant differences in dimensional change were noted between materials across time (P < .05). All materials exhibited shrinkage after 30 minutes, with the conventional alginate continuing to shrink over time and the extended-storage alginates expanding with increased storage time. The conventional alginate was most accurate after 30 minutes. In contrast, one extended-storage alginate demonstrated minimal dimensional change at all storage times, and another was most accurate after 100-hour storage.
CONCLUSIONS
Evidence suggests that delayed pouring with dental gypsum should not adversely affect dimensional accuracy of the generated casts with both extended-storage alginates. However, only one of the extended-storage materials appears suitable for both short-term and extended-storage applications.