A comparative evaluation of plastic and metal impression trays on the accuracy of cast

Abstract

Background: Defects in making an impression could affect the accuracy and fit of the final prostheses. Aims and Objectives: The present study evaluates whether the rigidity of impression trays made out of two different materials affect the accuracy of cast poured out of same impression material. Materials and Methods: For the present study, metallic perforated rim-lock tray and disposable plastic tray were selected for making the impression. Alginate (Tropicalgin™) was used as the impression material of choice. A master model constructed with stainless steel abutments at 44 and 47 and 34 and 37 region was used for making impressions using metal and plastic impression trays respectively. The cast was poured with type III dental stone and the distance between the reference points were measured using CMM (Coordinate Measuring Machine). The results obtained were compared and statistical analysis done using one sample t – test. Results: The study came out with results showing statistically significant differences (P Conclusions: The study concluded that rigidity of perforated metal stock trays ensured better results than perforated plastic stock trays for impressions using alginate impression material.