Effectiveness of hardening films on die stone.

1. Cyanoacrylate resins and resinous die hardeners effectively improved the hardness and abrasion resistance of stone dies. 2. Application of liquid resins followed by blotting and/or blowing with compressed air produced an improved surface without clinically significant dimensional change. The extent of film buildup was qualitatively related to the viscosity of the resin. 3. Application of multiple coats of resin or simply soaking the dies in resin without further blotting or other mode of removal of the excess produced a thick film which can obliterate surface detail.