United States Air Force, Advanced Education in General Dentistry Residency, Travis AFB, CA, USA.
J Prosthodont. 2010 Aug;19(6):478-81. doi: 10.1111/j.1532-849X.2010.00599.x. Epub 2010 Apr 29.
Mechanical spatulation of alginate impression materials reportedly produces fewer voids and superior casts than hand mixing. Two current methods of alginate mechanical preparation are a vacuum mixer Vac-U-Vestor, (Whip Mix Corp, Louisville, KY) and a semiautomated method that involves hand spatulation in a rotating bowl Alginator II (Cadco, Oxnard, CA). A new alginate-mixing machine has been introduced, TurboMax (Dentsply Raintree Essex, Sarasota, FL), with a centrifugal-spinning action that reportedly incorporates the alginate powder into the water more efficiently. The purpose of this study was to determine the number, percent, and volume distribution of porosities in alginate mixed with three mechanical-mixing methods using a nondestructive, microtomographic analysis method.
Alginate was mixed by each of the three mechanical methods per respective manufacturer's guidelines, with the set alginate analyzed using a microtomography unit and proprietary software. A mean and standard deviation was determined per group and analyzed with Kruskal-Wallis ANOVA/Mann-Whitney tests.
Significant differences (p < 0.001) were found between groups per each of the three testing parameters (number, percent, volume distribution of porosities). The vacuum mixer produced significantly less percent porosity and number of porosities than the centrifugal mixer and semiautomated hand mixer. Both the vacuum mixer and centrifugal mixer produced porosities of significantly smaller volume than the semiautomated hand mixer.
Of the three mechanical mixing methods, the vacuum mixer had the best performance overall in reducing the number, percent, and volume of porosities in the mixed alginate.
据报道，与手动混合相比，使用机械搅拌藻酸盐印模材料可产生更少的空隙和更好的铸件。目前有两种藻酸盐机械准备方法，一种是真空混合器 Vac-U-Vestor（Whip Mix Corp，路易斯维尔，KY），另一种是半自动方法，涉及在旋转碗中手动搅拌 Alginator II（Cadco，Oxnard，CA）。一种新的藻酸盐混合机已被引入，即 TurboMax（Dentsply Raintree Essex，萨拉索塔，FL），其离心旋转动作据称能更有效地将藻酸盐粉末混入水中。本研究的目的是使用无损微断层分析方法确定三种机械混合方法混合的藻酸盐中的孔隙数量、百分比和体积分布。
按照每个制造商的指南，通过三种机械方法中的每一种混合藻酸盐，使用微断层分析单元和专有的软件对设定的藻酸盐进行分析。对每组数据进行平均值和标准差的计算，并进行 Kruskal-Wallis ANOVA/Mann-Whitney 检验分析。
在三个测试参数（孔隙数量、百分比、体积分布）中的每一个参数中，各组之间都存在显著差异（p<0.001）。真空混合器产生的孔隙百分比和孔隙数量明显少于离心混合器和半自动手动混合器。真空混合器和离心混合器产生的孔隙体积都明显小于半自动手动混合器。
在三种机械混合方法中，真空混合器在减少混合藻酸盐中的孔隙数量、百分比和体积方面的性能总体上最好。
