Effect of burn-out temperature on magnetic keepers in cast noble metal alloy posts.
J Prosthet Dent
; 101(1): 66-72, 2009 Jan.
Article
en En
| MEDLINE
| ID: mdl-19105993
ABSTRACT
STATEMENT OF PROBLEM:
Early loss of magnetic keepers in cast gold posts is seen in clinical practice.PURPOSE:
The purpose of this vitro study was to investigate the effect of burn-out temperature on the retention of magnetic keepers in cast gold alloy and on the thickness of the oxide layer at the keeper-alloy interface. MATERIAL ANDMETHODS:
One hundred and five keepers (Magfit EX) were cast with gold alloy (Protor 3) at 3 different burn-out temperatures 500 degrees C, 600 degrees C, or 700 degrees C (n=35). To test for retention of keepers, 60 specimens (n=20) were tested to failure in tension mode in a universal testing machine (UTM); 45 specimens (n=15) were sectioned, and the interface was evaluated under a scanning electron microscope (SEM). Tensile force data were analyzed with 1-way ANOVA, and SEM data were analyzed with 1-way repeated measures ANOVA. Bonferroni multiple comparisons were performed for post hoc analysis (alpha=.05).RESULTS:
Retention of the keepers was significantly higher at lower burn-out temperatures (P<.001). The retention of the keepers became unpredictable and immediate failures were observed at a burn-out temperature of 700 degrees C. Oxide formation at the keeper-alloy interface was significantly less at lower burn-out temperatures (P<.001).CONCLUSIONS:
A burn-out temperature of 500 degrees C for casting the Magfit EX keeper with type IV high-strength gold alloy is recommended.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Técnica de Colado Dental
/
Técnica de Perno Muñón
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Retención de Dentadura
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Fracaso de la Restauración Dental
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Aleaciones de Oro
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Magnetismo
Idioma:
En
Revista:
J Prosthet Dent
Año:
2009
Tipo del documento:
Article
País de afiliación:
China
Pais de publicación:
EEUU
/
ESTADOS UNIDOS
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ESTADOS UNIDOS DA AMERICA
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EUA
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UNITED STATES
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UNITED STATES OF AMERICA
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US
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USA