无牙颌下颌开窗式印模技术

Window-opening impression techniques for edentulous mandibular ridges

重度吸收的无牙颌下颌牙槽嵴,其表面常被覆有过度增生的条索状黏膜组织,如何制取这些组织的精确印模是临床常见难题之一。本文介绍了1种无牙颌下颌开窗式印模制取方法。首先通过在无牙颌个别托盘相应区域开窗,充分显露出增生黏膜组织,使得医师可以在取模过程中随时准确观察这些组织状况。其次本文应用了2种新的印模材料——流体印模蜡与聚硫硅橡胶材料,分别用于制取正常黏膜组织与增生黏膜软组织区域的印模,获得了精确的下颌无牙颌印模。这种开窗式印模的特点是印模操作时间充分,两步式取模方式不会挤压组织变形,能够准确反映下颌无牙颌组织形态。

Impressions of mandibular ridges with displaceable tissues are very challenging for prosthodontists in clinic.This article describes a new technique for making a definitive impression for highly displaceable residual mandibular edentulous ridges.Firstly a window was created in the tray over the crest of the residual ridge,which exposed the displaceable soft mucosa tissue.Thus,the prosthodontist can view the tissue directly at anytime during the impression process.Following two new dental impression material were applied to capture the shape of the residual ridge and place pressure onto denture load-bearing areas.A fluid wax impression was to take the impression over the area without displaceable soft mucosa tissue.Polysulfide impression material was then used over the window opening to capture the surface details of the residual ridge without distorting the displaceable tissues.The choice of the impression materials focuses on preventing any distortion of the displaceable residual ridges during impression making.The advantages of this technique are to have enough working time as well as accurate contour of the edentulous mandibular ridge.