Shibayama Ricardo, Gennari Filho Humberto, Mazaro José Vitor Quinelli, Vedovatto Eduardo, Assunção Wirley Gonçalves
Dental Prostheses and Occlusion, Department of Restorative Dentistry, Londrina State University, Brazil.
J Prosthodont. 2009 Apr;18(3):259-64. doi: 10.1111/j.1532-849X.2008.00421.x. Epub 2009 Feb 2.
The purpose of this study was to compare the artificial tooth positional changes following the flasking and polymerization of complete dentures by a combination of two flasking methods and two polymerization techniques using computer graphic measurements.
Four groups of waxed complete dentures (n = 10) were invested and polymerized using the following techniques: (1) adding a second investment layer of gypsum and conventional water bath polymerization (Control), (2) adding a second investment layer of gypsum and polymerization with microwave energy (Gypmicro), (3) adding a second investment layer of silicone (Zetalabor) and conventional polymerization (Silwater), and (4) adding a second investment layer of silicone and polymerization with microwave energy (Silmicro). For each specimen, six segments of interdental distances (A to F) were measured to determine the artificial tooth positions in the waxed and polymerized stages using software program AutoCad R14. The mean values of the changes were statistically compared by univariate ANOVA with Tukey post-hoc test at 5% significance.
There were no significant differences among the four groups, except for segment D of the Silmicro group (-0.004 +/- 0.032 cm) in relation to the Gypwater group (0.044 +/- 0.031 cm) (p < 0.05), which presented, respectively, expansion and shrinkage after polymerization.
Within the limitations of this study, it was concluded that although the differences were not statistically significant, the use of a silicone investment layer when flasking complete dentures resulted in the least positional changes of the artificial teeth regardless of the polymerization technique.
本研究的目的是通过计算机图形测量，比较两种装盒方法和两种聚合技术相结合在全口义齿装盒和聚合后人工牙位置的变化。
四组蜡型全口义齿（n = 10）采用以下技术包埋并聚合：（1）添加第二层石膏包埋料并采用传统水浴聚合（对照组），（2）添加第二层石膏包埋料并采用微波能量聚合（石膏 - 微波组），（3）添加第二层硅橡胶（Zetalabor）包埋料并采用传统聚合（硅橡胶 - 水浴组），（4）添加第二层硅橡胶包埋料并采用微波能量聚合（硅橡胶 - 微波组）。对于每个标本，测量六个牙间隙距离段（A至F），使用软件程序AutoCad R14确定蜡型和聚合阶段的人工牙位置。变化的平均值通过单因素方差分析和Tukey事后检验进行统计学比较，显著性水平为5%。
四组之间除硅橡胶 - 微波组的D段（-0.004±0.032 cm）与石膏 - 水浴组（0.044±0.031 cm）相比有显著差异（p < 0.05）外，其他无显著差异，聚合后分别出现扩张和收缩。
在本研究的局限性内，得出的结论是，尽管差异无统计学意义，但在全口义齿装盒时使用硅橡胶包埋料，无论聚合技术如何，人工牙的位置变化最小。
