Ozyemisci Nuran, Yorulmaz Mehmet
Hacettepe University, Dental Prosthesis Technology Program, Vocational School of Health Services, Ankara,Turkey.
Canakkale Onsekiz Mart University, Faculty of Dentistry,Canakkale,Turkey.
Eur Oral Res. 2020 Sep 1;54(3):119-122. doi: 10.26650/eor.20200098.
An essential of successful dental prosthesis is dental models. Voids present in dental models decreases accuracy and strength. This study investigates void formation in models fabricated by a new technique. The technique described in the study was based upon increasing soaking time of gypsum powder in water.
Voids in hand mixed, hand mixed after a soaking time of 1.5 minutes and vacuum mixed samples were examined. The voids were counted via a stereomicroscope and diameters of voids were recorded in 2 categories (0.01-0.05mm, 0.051-0.1mm). The amounts of voids were compared between the samples prepared with 3 methods.
The samples prepared by conventional hand mixing method had the highest total number of voids and smaller voids. There was no significant difference between the amount of voids in the samples prepared by soaking powder in water and by mixing under vacuum.
Soaking gypsum powder in water for 1.5 minutes before mixing may be an alternative to mixing gypsum under vacuum to avoid void formation in dental models.
成功制作假牙的关键要素之一是牙齿模型。牙齿模型中出现的空隙会降低其准确性和强度。本研究调查了一种新技术制作的模型中孔隙的形成情况。该研究中描述的技术基于增加石膏粉在水中的浸泡时间。
对手工搅拌、浸泡1.5分钟后手工搅拌以及真空搅拌的样本中的空隙进行检查。通过体视显微镜对空隙进行计数，并将空隙直径记录为两类（0.01 - 0.05毫米、0.051 - 0.1毫米）。比较了用三种方法制备的样本之间的空隙数量。
采用传统手工搅拌方法制备的样本空隙总数最多且空隙较小。将粉末浸泡在水中制备的样本与真空搅拌制备的样本在空隙数量上没有显著差异。
在混合前将石膏粉在水中浸泡1.5分钟可能是一种替代在真空中混合石膏的方法，以避免牙齿模型中形成空隙。
