In Vitro Comparative Evaluation of Different Types of Impression Trays and Impression Materials on the Accuracy of Open Tray Implant Impressions: A Pilot Study.

Sonam Gupta,Dhanasekar Balakrishnan,Aparna Ichalangod Narayan

doi:10.1155/2017/6306530

Sonam Gupta, Dhanasekar Balakrishnan + Show 1 more

Open Access

https://doi.org/10.1155/2017/6306530

Copy DOI

Abstract

Purpose. For a precise fit of multiple implant framework, having an accurate definitive cast is imperative. The present study evaluated dimensional accuracy of master casts obtained using different impression trays and materials with open tray impression technique. Materials and Methods. A machined aluminum reference model with four parallel implant analogues was fabricated. Forty implant level impressions were made. Eight groups (n = 5) were tested using impression materials (polyether and vinylsiloxanether) and four types of impression trays, two being custom (self-cure acrylic and light cure acrylic) and two being stock (plastic and metal). The interimplant distances were measured on master casts using a coordinate measuring machine. The collected data was compared with a standard reference model and was statistically analyzed using two-way ANOVA. Results. Statistically significant difference (p < 0.05) was found between the two impression materials. However, the difference seen was small (36 μm) irrespective of the tray type used. No significant difference (p > 0.05) was observed between varied stock and custom trays. Conclusions. The polyether impression material proved to be more accurate than vinylsiloxanether impression material. The rigid nonperforated stock trays, both plastic and metal, could be an alternative for custom trays for multi-implant impressions when used with medium viscosity impression materials.

Highlights

Oral rehabilitation of partial and complete edentulism with osseointegrated implants has presently become a conventional treatment and its longitudinal effectiveness as one of the viable treatment modalities has been proven by several clinical studies [1, 2]
With regard to the results obtained, the first null hypothesis was rejected that there would be no significant difference in the dimensional accuracy of cast in terms of linear and cross-arch discrepancies between PE and VSXE impression material
(1) The casts obtained from impressions made with polyether impression material proved to be more accurate statistically than casts obtained from vinylsiloxanether impression material

Summary

Introduction

Oral rehabilitation of partial and complete edentulism with osseointegrated implants has presently become a conventional treatment and its longitudinal effectiveness as one of the viable treatment modalities has been proven by several clinical studies [1, 2]. The advent of implant dentistry has exemplified the urgency for a precisely fitting final prosthesis [3]. Since endosseous implants are functionally ankylosed, they are in direct contact with the bone, as a result lack inherent mobility of the periodontal ligament [4]. On the contrary natural teeth have the ability to resist horizontal, vertical, and rotational forces because of the stress bearing capacity of the periodontal ligament. Misfit of these frameworks could load the implants unnecessarily and jeopardize their longevity. Precise fit of the framework becomes more critical when final restorations are attached to implants as compared to natural teeth [5]. Any misalignment between the osseointegrated implants and its superstructure may invoke stresses in the dentures, implants, and the periimplant bone matrix [6, 7]

Methods

Discussion

Conclusion