Effect of hydrofluoric acid etching duration on the roughness and flexural strength of a lithium disilicate-based glass ceramic

The aim of this study was to examine the effect of different acid etching times on the surface roughness and flexural strength of a lithium disilicate-based glass ceramic. Ceramic bar-shaped specimens (16 mm x 2 mm x 2 mm) were produced from ceramic blocks. All specimens were polished and sonically...

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Detalles Bibliográficos
Autores: Zogheib, Lucas Villaça, Della Bona, Alvaro, Kimpara, Estevão Tomomitsu [UNESP], Mccabe, John F.
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2011
País:Brasil
Institución:Universidade Estadual Paulista (UNESP)
Repositorio:Repositório Institucional da UNESP
Idioma:inglés
OAI Identifier:oai:repositorio.unesp.br:11449/72424
Acceso en línea:http://dx.doi.org/10.1590/S0103-64402011000100008
http://hdl.handle.net/11449/72424
Access Level:acceso abierto
Palabra clave:CAD/CAM
Flexural strength
Hydrofluoric acid
Lithium disilicate glass ceramic
Roughness
hydrofluoric acid
lithia disilicate
chemistry
dental acid etching
dental bonding
dental care
materials testing
methodology
pliability
randomization
scanning electron microscopy
surface property
time
tooth prosthesis
Acid Etching, Dental
Dental Bonding
Dental Porcelain
Dental Stress Analysis
Hydrofluoric Acid
Materials Testing
Microscopy, Electron, Scanning
Pliability
Random Allocation
Surface Properties
Time Factors
Descripción
Sumario:The aim of this study was to examine the effect of different acid etching times on the surface roughness and flexural strength of a lithium disilicate-based glass ceramic. Ceramic bar-shaped specimens (16 mm x 2 mm x 2 mm) were produced from ceramic blocks. All specimens were polished and sonically cleaned in distilled water. Specimens were randomly divided into 5 groups (n=15). Group A (control) no treatment. Groups B-E were etched with 4.9% hydrofluoric acid (HF) for 4 different etching periods: 20 s, 60 s, 90 s and 180 s, respectively. Etched surfaces were observed under scanning electron microscopy. Surface profilometry was used to examine the roughness of the etched ceramic surfaces, and the specimens were loaded to failure using a 3-point bending test to determine the flexural strength. Data were analyzed using one-way ANOVA and Tukey's test (α=0.05). All etching periods produced significantly rougher surfaces than the control group (p<0.05). Roughness values increased with the increase of the etching time. The mean flexural strength values were (MPa): A=417 ± 55; B=367 ± 68; C=363 ± 84; D=329 ± 70; and E=314 ± 62. HF etching significantly reduced the mean flexural strength as the etching time increased (p=0.003). In conclusion, the findings of this study showed that the increase of HF etching time affected the surface roughness and the flexural strength of a lithium disilicate-based glass ceramic, confirming the study hypothesis.