J Korean Acad Prosthodont.  1999 Jun;37(3):383-394.

DIMENSIONAL ACCURACY OF EPOXY RESINS AND THEIR COMPATIBILITY WITH IMPRESSION MATERIALS

• Chang SK
• Chang IT
• Yim SH

Abstract

The indirect technique for making cast restoration requires that dies be as accurate and durable as possible. Currently, stone is the most commonly used material for die. However, it has some problems such as the weakness in its strength and low abrasion resistance. Recently, epoxy resin die systems have become available. The purpose of this study was to examine two commercially available resin die systems and evaluate some characteristics for their clinical performance. This study evaluated the dimensional accuracy of epoxy resins and their wettability with impression materials. In this study, the first experiment was about dimensional accuracy of different die materials. The master model was made of stainless steel. 10 models were made of two epoxy resins (Die-epoxy, Tri-epoxy) and a die stone (Fujirock) each. Occlusal diameter (Dimension I), occluso-gingival height (Dimension II), and interabutment distance (Dimension III) wee measured in each model. Next, the contact angles of die materials with impression materials were observed. The blocks were made of polyether, hydrophilic additional silicone, polysulfide impression materials. By dropping the same amount (0.05ml) of Tri-epoxy, Die-epoxy, and die stone on the blocks, 10 samples of each die material were made. After setting of materials, the contact angles were measured. The results of this study were as follows. 1. The expansion of stone die and the shrinkage of resin dies in occlusal diameter were observed, and stone and Tri-epoxy were expanded and Die-epoxy was shrinked in occluso-gin-gival height. There was little change among materials in interabutment distance (p>0.05). 2. In comparison with the mater model, Tri-epoxy had the least variation in measurement of the three die systems examined. Did-epoxy was next, and die stone showed the greatest variation. 3. The compatibility of die stone for polyether, hydrophilic additional silicone, polysulfide decreased in order, wherease epoxy materials had the decreased compatibility for polyether and polysulfide, hydrophilic additional silicone in order. It was not statistically different between polyether and polysulifide (p>0.05). 4. The contact angles of Tri-epoxy, Die-epoxy, die stone were getting bigger in order.

MeSH Terms

Epoxy Resins*
Silicones
Stainless Steel
Wettability
Epoxy Resins
Silicones
Stainless Steel