Dimensional accuracy of a new polyether impression material.

Tatsuo Endo; Werner J Finger

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PubMed · 16429703

Dimensional accuracy of a new polyether impression material.

Tatsuo Endo·Werner J Finger

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Abstract

OBJECTIVES: The purpose of this study was to evaluate the dimensional accuracy of stone dies produced from standardized impressions with 1 new and 1 conventional polyether impression material and a polyvinyl siloxane reference material. METHODS AND MATERIALS: Impressions with the polyether materials P2 and Impregum and with the polyvinyl siloxane Flexitime were produced at 23 degrees C or 37 degrees C from a truncated steel cone in cylindrical steel trays giving 4-mm impression layer thickness at the prominence line. Stone dies were poured after 1 or 24 hours of storage at ambient atmosphere. Additional impressions were stored at different relative humidity levels (0%, 33%, 50%, 75%, or 100%) for 24 hours prior to die pouring. The accuracy of the stone dies was determined as axial discrepancy between a steel ring, which fit perfectly on the steel die and the occlusal die surface. The base-diameter deviation (deltad) was calculated. RESULTS: After 1 hour, a similar increase in deltad was noticed for impression materials when dies were poured at impression temperature. Impressions made at 37 degrees C exhibited significantly higher deltad than at 23 degrees C. Light-bodied P2 showed the highest deltad increase when dies were poured after 24 hours. Flexitime showed moderate deltad differences at the 2 pouring times. The deltad of dies made from polyether materials decreased significantly with increasing humidity, whereas polyvinyl siloxane was not adversely affected. CONCLUSION: The dimensional accuracy of P2 is comparable to that of the conventional polyether impression material after short-term storage. Polyethers may absorb water, significantly compromising die accuracy upon storage at high humidity.

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Absorption Calcium Sulfate Dental Impression Materials Dental Impression Technique Dental Materials Ethers Humans Humidity Materials Testing Models, Dental Polyvinyls Resins, Synthetic Siloxanes Steel Surface Properties Temperature Time Factors Journal Article

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Tatsuo Endo, Werner J Finger. 2006. Dimensional accuracy of a new polyether impression material.. https://pubmed.ncbi.nlm.nih.gov/16429703/

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