Salloum Alaa'a M
Department of Removable Prosthodontics, Faculty of Dental Medicine, Damascus University, Damascus, Syria.
Saudi Dent J. 2013 Oct;25(4):135-40. doi: 10.1016/j.sdentj.2013.10.002. Epub 2013 Oct 28.
Despite advances in materials and techniques, complete dentures made of acrylic resin experience an increase in the occlusal vertical dimension (OVD) during processing. Many factors that affect the OVD of complete dentures are known. However, no study has examined the effect of using high-expansion dental stone (type V) as an investing material on the OVD.
This study investigated the effects of using a high-expansion dental stone as an investing material on changes in the OVD of complete dentures.
Twenty sets of simulated upper and lower dentures were processed by the compression molding technique. Specimens were equally divided into 2 groups. In the dental stone type III (DST III) group, the lower, middle, and upper parts of a flask were filled with DST III. In the dental stone type V (DST V) group, the procedure was the same as in the DST III group, except that the middle layer was made of high-expansion DST V. Changes in the OVD were measured before and after denture processing. Collected data were analyzed with t-test statistics. Differences were considered statistically significant at the 95% confidence level.
Both groups showed a small increase in the OVD as a result of processing, but the OVD increase was significantly less in the DST V group compared to the DST III group.
High-expansion DST V can be recommended as an investing material to reduce the increase in the OVD that may occur while processing complete dentures.
尽管材料和技术有所进步，但由丙烯酸树脂制成的全口义齿在加工过程中咬合垂直距离（OVD）会增加。许多影响全口义齿OVD的因素是已知的。然而，尚无研究考察使用高膨胀牙科石膏（V型）作为包埋材料对OVD的影响。
本研究调查使用高膨胀牙科石膏作为包埋材料对全口义齿OVD变化的影响。
通过模压成型技术制作20副模拟上下颌义齿。标本平均分为2组。在III型牙科石膏（DST III）组中，型盒的下部、中部和上部填充DST III。在V型牙科石膏（DST V）组中，操作与DST III组相同，只是中间层由高膨胀DST V制成。在义齿加工前后测量OVD的变化。收集的数据用t检验统计分析。差异在95%置信水平被认为具有统计学意义。
两组在加工后OVD均有小幅增加，但DST V组的OVD增加量明显低于DST III组。
高膨胀DST V可推荐作为一种包埋材料，以减少全口义齿加工过程中可能出现的OVD增加。
