Browse by author
Lookup NU author(s): Dr Matthew GermanORCiD,
Professor John McCabe
Full text for this publication is not currently held within this repository. Alternative links are provided below where available.
Objectives. The purpose of this work was to discern, for elastomeric impression materials, the important rheological properties and importance of hydrophilicity for detail reproduction. Methods. Viscosity, modulus and tan delta were measured using a controlled-stress rheometer in cone/plate configuration. The flow of the materials, immediately after mixing and at the manufacturer's stated working time, was measured using a shark fin test and the interaction with moist surfaces was determined by taking impressions from two different sized grooves in moist gypsum casts. Results. Tan delta was found to be the parameter most indicative of the accuracy of the impression and the flow of the material. Impregum samples, a polyether material, exhibited the highest initial tan delta (7.4), the largest shark fins at both time periods and the most accurate impressions from both grooves. Aquasil, a polyvinylsiloxane material, had similar initial tan delta values (6.9) and impressions taken on the deep groove with this material closely matched the groove. The other two polyvinylsiloxane materials (Affinis and Flexitime) had significantly lower initial tan delta values (3.1 and 2.9, respectively), exhibited much smaller shark fins and a worse ability to accurately reproduce the deep groove. Significance. For large features, it is clear that the higher the initial tan delta of the impression material the better the ability to replicate larger features. However, with smaller features the relative hydrophobicity of the material becomes an important factor, with more hydrophilic materials better able to reproduce fine detail. (c) 2007 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.
Author(s): German MJ, Carrick TE, McCabe JF
Publication type: Article
Publication status: Published
Journal: Dental Materials
ISSN (print): 0109-5641
ISSN (electronic): 1879-0097
Publisher: Elsevier Inc.
Altmetrics provided by Altmetric