Comportamento de fratura sob carga estática e cíclica das cerâmicas odontológicas quando unidas a um substrato análogo à dentina
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Data
2012-02-02
Autores
Salazar Marocho, Suzana María [UNESP]
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Editor
Universidade Estadual Paulista (Unesp)
Resumo
Os objetivos desse estudo foram: 1) determinar a porosidade (%) dos agentes cimentantes (Panavia F (PF), Variolink II low (VLL) e high viscosity (VLH) e Rely X U100 (RU)) quando interpostos entre dois substratos, material cerâmico e resina com módulo de elasticidade semelhante à dentina (NG10); 2) Determinar o comportamento de fratura de uma porcelana odontológica (VM7), de uma cerâmica policristalina de infra-estrutura (YZ), e da YZ recoberta por uma porcelana odontológica (VM9) quando unidas (complexo cerâmica-cimento-NG10) e não unidas adesivamente ao substrato de NG10 quando submetidas a carga de fratura estática; 3) Determinar o comportamento de fratura do complexo cerâmica-cimento- NG10 quando submetidos ao teste de fadiga cíclica após armazenagem em meio úmido; e 4) determinar o modo e origem da falha das estruturas fraturadas, após o teste estático e fadiga cíclica. Espécimes como: 1) Discos monolíticos de VM7 (n= 40), 2) VM7+agente cimentante (n= 20), 3) VM7+agente cimentante+NG10 (n=320), e 4) V9/YZ+agente cimentante+NG10 (n= 320) foram confeccionados e testados em compressão após 24 h, 1 mês, 3 e 6 meses de armazenagem em meio úmido. O grupo 3) foi avaliado sob efeito de fadiga cíclica, aplicando-se o 60% do valor da carga de fratura do teste estático. A porosidade (%) presente na camada de cada agente cimentante quando interposto no conjunto cerâmica-NG10 foi semelhante foi semelhante após aplicação da carga de fratura estática e cíclica. A união adesiva das estruturas cerâmicas ao substrato análogo à dentina influenciou no comportamento à fratura dos conjuntos formados pela porcelana V7. Os valores de carga de fratura estática foram superiores para a cerâmica YZ independente da união adesiva ao NG10. A porcelana de recobrimento da YZ se mostrou...
The aim of this research was 1) to investigate the porosity (%) of resin cements (RC) when adhesively bonded to a ceramic material and a dentin analog material (NG10); 2) determine the fracture load of a porcelain (VM7), a polycrystalline framework ceramic (YZ), and a YZ veneered with a porcelain (VM9) bonded to NG10; 3) determine the fatigue lifetime of the ceramic-RC-NG10 assemblies; and 4) determine the mode of failure and the initial defect size of ceramic structures after compression and fatigue testing. 1) VM7 monolithic disks (V7) (n=40), 2) VM7+RC (V7.RC) (n=20), 3) VM7+RC+NG10 (V7.RC.NG10) (n=320), and 4) VM9/YZ+RC+NG10 (V9/YZ.RC.NG10) (n=320) were built up, wet aged for 24 h, 1 month, 3 and 6 months, and tested under compression test. The compressive force required to cause fracturing was recorded in Newtons (N). The following RC were used: Panavia F (PF), Variolink II low (VLL) and high viscosity (VLHV) and Rely X U100 (RU). V7 groups were subjected to compressive fatigue loading. At both tests, the crosshead movement was stopped when the first discontinuity appeared in the recording chart, indicating early crack formation. The porosity (%) of the RC layer in each assembly was similar among all groups, except for the ones cemented with VLL. After the first 3 months, the characteristic fracture load of V7.RC.NG10 groups was similar, except for V7.VLL.NG10. The former group showed the best mechanical behavior. The fracture compressive values were higher for YZ than for V7, even independently of dentin bonding. All the YZ assemblies’ fractures occurred within the veneering layer during the fatigue test. There was a significant difference between the survival rates of the complexes during the fatigue test. The performance of YZ assemblies was superior to V7 in the compressive and fatigue test... (Complete abstract click electronic access below)
The aim of this research was 1) to investigate the porosity (%) of resin cements (RC) when adhesively bonded to a ceramic material and a dentin analog material (NG10); 2) determine the fracture load of a porcelain (VM7), a polycrystalline framework ceramic (YZ), and a YZ veneered with a porcelain (VM9) bonded to NG10; 3) determine the fatigue lifetime of the ceramic-RC-NG10 assemblies; and 4) determine the mode of failure and the initial defect size of ceramic structures after compression and fatigue testing. 1) VM7 monolithic disks (V7) (n=40), 2) VM7+RC (V7.RC) (n=20), 3) VM7+RC+NG10 (V7.RC.NG10) (n=320), and 4) VM9/YZ+RC+NG10 (V9/YZ.RC.NG10) (n=320) were built up, wet aged for 24 h, 1 month, 3 and 6 months, and tested under compression test. The compressive force required to cause fracturing was recorded in Newtons (N). The following RC were used: Panavia F (PF), Variolink II low (VLL) and high viscosity (VLHV) and Rely X U100 (RU). V7 groups were subjected to compressive fatigue loading. At both tests, the crosshead movement was stopped when the first discontinuity appeared in the recording chart, indicating early crack formation. The porosity (%) of the RC layer in each assembly was similar among all groups, except for the ones cemented with VLL. After the first 3 months, the characteristic fracture load of V7.RC.NG10 groups was similar, except for V7.VLL.NG10. The former group showed the best mechanical behavior. The fracture compressive values were higher for YZ than for V7, even independently of dentin bonding. All the YZ assemblies’ fractures occurred within the veneering layer during the fatigue test. There was a significant difference between the survival rates of the complexes during the fatigue test. The performance of YZ assemblies was superior to V7 in the compressive and fatigue test... (Complete abstract click electronic access below)
Descrição
Palavras-chave
Cimentos dentarios, Cerâmica odontológica, Materiais dentários, Cimentos de resina
Como citar
SALAZAR MAROCHO, Suzana María. Comportamento de fratura sob carga estática e cíclica das cerâmicas odontológicas quando unidas a um substrato análogo à dentina. 2012. 169 f. Tese (doutorado) - Universidade Estadual Paulista, Faculdade de Odontologia de São José dos Campos, 2012.