Comparing effects of tray treatment on the accuracy of dies.

The effects of tray treatments on the accuracy of dies from addition silicone impressions were investigated. Tray treatments included custom acrylic resin tray with adhesive, perforated custom acrylic resin tray without adhesive, and perforated custom acrylic resin tray with adhesive. No appreciable differences were found in the complete crowns among the three tray treatments on the first pours. Significant statistical differences observed in the MOD and occlusal inlays were nonetheless of questionable clinical significance. Adhesives are advisable if the impressions are poured repeatedly, however, to minimize accidental separation of the impression from the tray. The second casts were less accurate with complete crowns and MOD inlays when perforated trays were used without adhesives.