The surface of investments poured against different duplicating media.
Two phosphate-bonded investments that were poured into molds of a duplicating gel and a poly(vinyl siloxane) duplicating medium were examined for surface hardness. Untreated surfaces were also examined by the confocal microscope and the scanning electron microscope. The Brinell hardness of samples poured in poly(vinyl siloxane) was greater than that of the same investment poured in duplicating gel. Investments were hardest as set and were significantly softened by drying. Cast hardeners achieved some rehardening of the dried investment samples. Microscopic examination of the investment surfaces revealed greater irregularity of samples poured in duplicating gel than in poly(vinyl siloxane), particularly in one investment.
Likeman
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PR
Department of Prosthetic Dentistry, United Medical and Dental School of Guy's and St. Thomas' Hospitals, London, England.
Radford
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DR
Juszczyk
A S
AS
D000362:Agar; D000704:Analysis of Variance; D002858:Chromium Alloys; D003734:Dental Casting Investment / Q000737:chemistry*; D003735:Dental Casting Technique / Q000295:instrumentation; D005782:Gels; D006244:Hardness; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D011145:Polyvinyls; D015203:Reproducibility of Results; D012833:Siloxanes; D013499:Surface Properties
D002858:Chromium Alloys; D003734:Dental Casting Investment; D005782:Gels; D011145:Polyvinyls; D012833:Siloxanes; C034183:vinyl polysiloxane; D000362:Agar