European Journal of Prosthodontics and Restorative Dentistry

cover art

Cover Date:
December 2010
Print ISSN:
0965-7452
Vol:
18
Issue:
4

Extrusion-Mixing Compared with Hand-Mixing of Polyether Impression Materials ?

Abstract - The hypotheses tested were two-fold (a) whether altering the base:catalyst ratio influences working time, elastic recovery and strain in compression properties of a hand-mixed polyether impression material and (b) whether an extrusion-mixed polyether impression material would have a significant advantage over a hand-mixed polyether impression material mixed to the optimum base:catalyst ratio. The polyether was hand-mixed at the optimum (manufacturers recommended) base:catalyst ratios (7:1) and further groups were made by increasing or decreasing the catalyst length by 25%. Additionally specimens were also made from an extrusion-mixed polyether impression material and compared with the optimum hand-mixed base:catalyst ratio. A penetrometer assembly was used to measure the working time (n=5). Five cylindrical specimens for each hand-mixed and extrusion mixed group investigated were employed for elastic recovery and strain in compression testing. Hand-mixing polyether impression materials with 25% more catalyst than that recommended significantly decreased the working time while hand-mixing with 25% less catalyst than that recommended significantly increased the strain in compression. The extrusion-mixed polyether impression material provided similar working time, elastic recovery and strain in compression to the hand-mixed polyether mixed at the optimum base:catalyst ratio.

KEY WORDS: base:catalyst ratio, polyether impression materials

Article Price
£15.00
Institution Article Price
£
Page Start
150
Page End
154
Authors
Caroline McMahon, Daniel Kinsella, Garry J.P. Fleming

Articles from this issue

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  1. Extrusion-Mixing Compared with Hand-Mixing of Polyether Impression Materials ?
  2. 150
  3. 154

  1. Crown Retention for Non-Retentive Preparations using Adhesive Resin Cements
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  1. The Relationship Between Fibre Post Geometry and Flexural Properties: An Assessment Through a Modified Three-Point Bending Test
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  1. Dimensional Stability of Newer Alginate Impression Materials over Seven Days
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  1. Repeatability of Electronic Shade Determination and the Influence of Differences in Patient’s Sitting Position.
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  1. Frechette Awards 2010
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  1. Surface Characteristic Changes of Dental Ceramics after Cyclic Immersion in Acidic Agents and Titratable Acidity
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  1. Evaluation of Bonding Behavior of Silver-Tin-ZincIndium Alloy to Adhesive Luting Cements
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