Comparison of impression techniques and double pouring by dental cast’s accuracy

Aion Mangino Messias,Raphael Freitas De Souza,Filipe De Oliveira Abi-Rached,Stephania Caroline Rodolfo Silva,José Maurício Dos Santos Nunes Reis

doi:10.20396/bjos.v18i0.8657273

Aion Mangino Messias, Raphael Freitas De Souza + Show 3 more

Open Access

https://doi.org/10.20396/bjos.v18i0.8657273

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Abstract

Aim: This study compared impression techniques and double pouring by means of cast’s accuracy. Methods: For each patient (n=10), impressions from right maxillary canine to first molar were made with acrylic resin trays and vinyl-polysiloxane using one single-step, and four two-steps techniques: relief with poly(vinyl chloride) film; tungsten-carbide bur/scalpel blade; small movements of the tray; non-relief. Total visible buccal surface area of crowns was measured three times using photographs from patients (Baseline) and casts. Mean area values (mm2) between Baseline and casts differences were analyzed by two-way repeated-measures ANOVA (α=.05; 1-β=85%). Results: No significant differences were observed for Impression Techniques (P=.525), Double Pouring (P=.281), and their interaction (P=.809). Conclusion: All impression techniques and double pouring produced casts with similar accuracy.

Highlights

Accurate impression is an integral step for fabricating well-fitting restorations
Stone dies must be made for improving marginal fit of crowns
Current techniques for making removable dies have become more accurate, cutting a stone die out may result in dimensional change between abutments[3]

Summary

Introduction

Accurate impression is an integral step for fabricating well-fitting restorations. Vinyl-polysiloxane (VPS) stands out due to its excellent chemical and physical properties[1]. Impressions can be made with custom or stock trays, the optimum accuracy is obtained with the custom ones[2]. Regarding the techniques, there is no consensus with respect to the best one. Stone dies must be made for improving marginal fit of crowns. Current techniques for making removable dies have become more accurate, cutting a stone die out may result in dimensional change between abutments[3]. Producing more than one cast from the same impression is an option for preserving marginal fit. This study aimed to compare impression techniques and double pouring by means of cast’s accuracy

Objectives

Methods

Conclusion