The indirect restoration that does not fit its preparation is the most common error that the restorative dentistry faces today. The problem is still faced despite the presence of dimensionally stable and low shrinkage elastomeric impression materials such as polyvinyl siloxane. Aims and
Objectives: this study was conducted to evaluate the effect of tray selection on the accuracy of stone dies.
Materials and Methods: Ten impressions of the master model are made with the stock and complete arch custom tray each. The casts made from the impressions of the master model in type IV dental stone high strength (Ultrarock, Kalabhai, Karson Pvt. Ltd., India) are categorized as Group I: casts made from stock tray. Group II: casts made from complete arch custom tray. Abutment preparation height and width and inter-abutment separation on group I and group II casts are measured with travelling microscope.
Results: the measurements of the stone dies made from stock and custom trays are subjected to statistical analysis of mean, standard deviation and percentage deviation. Percentage deviation was measured by dividing the difference of mean of stone model (msm) and mean of master model (mmm) by mean of master model multiplied by 100.
Conclusion: the custom tray produces more accurate dies than stock tray as it provides uniform and minimum thickness to the bulk of impression material. As far as the stock tray is concerned, that provides non-uniform and greater thickness to the bulk of impression material, produces greater distortion in the dies.