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A Quality Assessment of the Casting Process on Magnetic Keepers
Author(s) -
Luk Henry W.K.,
Pow Edmond H.N.,
Dias Andrew P.L.H.
Publication year - 2007
Publication title -
journal of prosthodontics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.902
H-Index - 60
eISSN - 1532-849X
pISSN - 1059-941X
DOI - 10.1111/j.1532-849x.2007.00185.x
Subject(s) - materials science , scanning electron microscope , casting , alloy , metallurgy , investment casting , mold , cristobalite , die casting , composite material , quartz
Purpose : The objective of this study was to qualitatively investigate the effect of the burn‐out (mold) temperature, investment material, and casting alloy on the surface integrity of the Magfit EX keeper.Materials and Methods : Forty‐two Magfit EX keepers were waxed‐up, invested in five investment materials (Beauty‐Cast, Cristobalite, CM‐10, Cera‐Fina, Castorit‐super), and subjected to burn‐out temperatures ranging from 450 to 700°C at intervals of 50°C. The keeper samples were then cast into copings with three alloys (Castwell, Protor 3, Optimum) under standard conditions. The keeper surfaces were then examined under a microscope, and the compositions were assessed by an X‐ray micro‐analyzer in a scanning electron microscope (SEM). A new keeper served as control.Results : At a burn‐out temperature of 550°C, the keeper surface started to disintegrate. X‐ray micro‐analysis showed an increase in oxygen content with increasing temperature. At 700°C, the keeper surface disintegrated, and the composition differed markedly from that of the new keeper. The keeper surfaces were intact with all investments except those with Beauty‐Cast. The keeper surfaces were found to be damaged when the casting alloy was Optimum.Conclusions : Beauty‐Cast investment with a burn‐out temperature of 700°C is unsuitable for casting the Magfit EX keeper‐coping unit. Also, high fusing alloys are not recommended for casting Magfit EX keepers.