Internal adaptation of cast titanium crowns
J. appl. oral sci
;
15(4): 247-252, July-Aug. 2007. ilus, tab
Artículo
en Inglés
| LILACS
| ID: lil-463673
ABSTRACT
As the adaptation of titanium crowns obtained by Rematitan Plus investment, specific for titanium, is not recognized to be suitable, this study evaluated the effect of the concentration of the specific liquid and the temperature of the mold of investments on the internal misfit of crowns cast on commercially pure titanium. Individual dies of epoxy resin were obtained, representing teeth prepared for full-crown restoration with a 6-degree axial surface convergence angle and shoulder (1.0 mm). For the waxing of each crown, a ring-shaped stainless steel matrix (8.0mm internal diameter; 7.5 mm height) was adapted above the individual dies of epoxy resin. The Rematian Plus investment was mixed according to the manufacturer's instructions using two different concentrations of the specific liquid 100 percent, 75 percent. Casting was performed in a Discovery Plasma Ar-arc vacuum-pressure casting machine with molds at temperatures of 430°C, 515°C and 600°C. The crowns were cleaned individually in a solution (1 percent HF + 13 percent HNO3) for 10 min using a ultrasonic cleaner, with no internal adaptations, and luted with zinc phosphate cement under a 5 kg static load. The crown and die assemblies were embedded in resin and sectioned longitudinally. The area occupied by cement was observed using stereoscopic lens (10X) and measured by the Leica Qwin image analysis system (mm²). The data for each experimental condition (n=8) were analyzed by Kruskal-Wallis non-parametric test (á=0.05). The results showed that liquid dilution and the increase in mold temperature did not significantly influence the levels of internal fit of the cast titanium crowns. The lowest means (±SD) of internal misfit were obtained for the 430°C/100 percent (7.25 mm² ±1.59) and 600°C/100 percent (8.8 mm² ±2.25) groups, which presented statistically similar levels of internal misfit.
Texto completo:
Disponible
Índice:
LILACS (Américas)
Idioma:
Inglés
Revista:
J. appl. oral sci
Asunto de la revista:
Odontología
Año:
2007
Tipo del documento:
Artículo
País de afiliación:
Brasil
Institución/País de afiliación:
São Paulo State University/BR
/
University Paulista/BR
/
University of São Paulo/BR
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