Nanda Aditi, Koli Dheeraj Kumar, Kaur Harsimran
Department of Prosthodontics, Centre for Dental Education and Research, All India Institute of Medical Sciences, New Delhi, India.
Department of Dental Surgery, VMMC and Safdarjung Hospital, New Delhi, India.
Contemp Clin Dent. 2024 Jul-Sep;15(3):220-222. doi: 10.4103/ccd.ccd_159_24. Epub 2024 Sep 25.
The objective is to minimize the inaccuracies in two-step impressions by homogenizing the polymerization shrinkage of elastomeric impression material in fixed prosthesis fabrication. The objective is accomplished by the technique of spacer adaptation and custom tray fabrication for two-step impressions. The technique makes the use of two vacuum-adapted spacers, selected based on the viscosity of elastomeric impression, and a vacuum-adapted custom tray. The procedure of using the specially fabricated custom tray for impression making is also presented. Consistent thickness of the two different viscosities of impression material is maintained due to vacuum adaptation of the spacers. This homogenizes the polymerization shrinkage of the elastomeric material in different regions of impression, as uniform space is occupied by the material in the space created by the spacer. The procedure of vacuum adaption of the tray material also limits the dimensional change of the tray. The technique minimizes the inaccuracies of impression by homogenizing the polymerization shrinkage of the elastomeric impression, thus promising a well-fitting prosthesis.
目的是通过使弹性印模材料在固定修复体制作中的聚合收缩均匀化，将两步印模中的误差降至最低。该目的通过用于两步印模的间隔物适配和定制托盘制作技术来实现。该技术使用两个根据弹性印模的粘度选择的真空适配间隔物和一个真空适配的定制托盘。还介绍了使用特制定制托盘进行印模制作的步骤。由于间隔物的真空适配，两种不同粘度的印模材料保持一致的厚度。这使得印模不同区域的弹性材料聚合收缩均匀化，因为在间隔物形成的空间中材料占据了均匀的空间。托盘材料的真空适配过程也限制了托盘的尺寸变化。该技术通过使弹性印模的聚合收缩均匀化，将印模误差降至最低，从而有望制作出贴合良好的修复体。
