Department of Prosthodontics and Research Institute of Oral Science, College of Dentistry, Gangneung-Wonju National University, Gangneung, South Korea.
J Prosthodont. 2019 Apr;28(4):444-451. doi: 10.1111/jopr.13036. Epub 2019 Feb 27.
To compare the effect of 3 tray designs and 3 commonly used impression materials on the displacement of flabby tissue during maxillary edentulous impression by superimposition of 3D digital models.
Fifteen maxillary edentulous casts with simulated flabby tissue were fabricated by modifying a standard maxillary edentulous acrylic resin cast. Three types of impression trays were fabricated: trays with conventional relief, trays with additional relief, and trays with an open window. Three impression materials were tested: light-body polysulfide, light-body vinylpolysiloxane, and zinc oxide eugenol paste. For the analysis of tissue displacement during impression making, the test and control stone casts were scanned using a 3D laser scanner, and the 3D digital models were superimposed using metrology software. Statistical analyses were performed with an α = 0.05.
Negative deviations were recorded at the areas of the alveolar crest, posterior part of flabby tissue, and middle of the palate. On the other hand, a positive deviation was recorded at the area of the anterior part of flabby tissue. A significant difference in the displacement of flabby tissue was found when using different tray designs (p < 0.0001). The tray with the open window showed significantly low tissue displacement at the flabby tissue region. Depending on sites, the amount of flabby tissue displacement showed different significances by the different impression materials used (anterior part: p < 0.0001; alveolar crest: p = 0.097; posterior part: p < 0.0001). Conventionally relieved trays showed significantly higher values of displacement at the anterior part of flabby tissue (p < 0.0001), while trays with open windows showed similar values of displacement at all measuring points, and no significant differences among different impression materials were found (p = 0.104).
There were significant differences in the displacement of flabby tissue with different tray designs, especially with displacement occurring at the anterior and posterior parts of flabby tissue. Tray designs should be considered in order to make proper impressions when flabby tissue is present.
通过对 3D 数字模型进行叠加，比较 3 种托盘设计和 3 种常用印模材料对上颌无牙颌印模时松软组织位移的影响。
通过修改标准上颌无牙颌丙烯酸树脂模型制作了 15 个带有模拟松软组织的上颌无牙颌模型。制作了 3 种类型的印模托盘：带有常规抬升区的托盘、带有附加抬升区的托盘和带有开口窗的托盘。测试了 3 种印模材料：轻质聚硫橡胶、轻质乙烯基聚硅氧烷和氧化锌丁香酚糊剂。为了分析印模制作过程中组织的位移，使用 3D 激光扫描仪对测试和对照石模型进行扫描，并使用计量软件对 3D 数字模型进行叠加。采用 α = 0.05 进行统计学分析。
牙槽嵴、松软组织后部和 palate 中部记录到负偏差。另一方面，在松软组织前部区域记录到正偏差。不同托盘设计对松软组织位移的影响有显著差异（p < 0.0001）。带有开口窗的托盘在松软组织区域显示出明显较低的组织位移。根据部位的不同，不同印模材料的使用导致松软组织位移的量有不同的显著性（前部：p < 0.0001；牙槽嵴：p = 0.097；后部：p < 0.0001）。常规抬升区的托盘在前部松软组织的位移值明显较高（p < 0.0001），而带有开口窗的托盘在所有测量点的位移值相似，不同印模材料之间没有发现显著差异（p = 0.104）。
不同托盘设计对松软组织的位移有显著差异，尤其是在松软组织的前部和后部。当存在松软组织时，应考虑托盘设计以获得适当的印模。
