McDaniel Thomas F, Kramer Robert T, Im Francis, Snow Dallin
Gen Dent. 2013 Sep-Oct;61(6):35-9.
Previous studies have found that variations in mixing technique can influence the porosity content of alginate impression material. The aim of this study was twofold: determine whether bubble formation in alginate is influenced by the sequence of water/powder addition prior to mixing, and to compare 4 different mixing techniques. Manual spatulation, an automated spinning bowl, a centrifugal mixer and a vacuum mixer were evaluated for the resulting porosity in the set alginate. It was found that adding powder first, versus water first, made no difference in the bubble content using the 3 automated mixing techniques (P = 0.714). However, porosity was significantly less for powder-first trials using manual spatulation (P < 0.05). It was also found that surface porosity in the resulting impressions was significantly less for centrifugal and vacuum mixing when compared to manual spatulation, while internal porosity was significantly less for centrifugal mixing compared to all other mixing techniques (P < 0.05). The centrifugal mixing and vacuum mixing techniques required the least amount of mixing time.
以往的研究发现，混合技术的差异会影响藻酸盐印模材料的孔隙率。本研究的目的有两个：确定藻酸盐中气泡的形成是否受混合前水/粉添加顺序的影响，并比较4种不同的混合技术。对手动调拌、自动旋转碗式搅拌器、离心式搅拌机和真空搅拌机在凝固后的藻酸盐中产生的孔隙率进行了评估。结果发现，对于3种自动混合技术，先加粉与先加水相比，气泡含量没有差异（P = 0.714）。然而，使用手动调拌时，先加粉试验的孔隙率显著更低（P < 0.05）。还发现，与手动调拌相比，离心搅拌和真空搅拌所得到的印模表面孔隙率显著更低，而与所有其他混合技术相比，离心搅拌的内部孔隙率显著更低（P < 0.05）。离心搅拌和真空搅拌技术所需的混合时间最少。
