Influência do processo de queima de cristalização na adesão de uma vitrocerâmica após envelhecimento hidrotérmico
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Data
2021-07-28
Autores
Rodrigues, Murilo Rocha [Unesp]
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Editor
Universidade Estadual Paulista (Unesp)
Resumo
Esse estudo avaliou a a influência do processo de queima de cristalização e degradação hidrotérmica na resistência união entre vitrocerâmicas à base de (di)silicato de lítio e o cimento resinoso. Foram confeccionados 90 blocos cerâmicos: 60 blocos de silicato de lítio reforçado por zircônia – Celtra Duo (Dentisply-Sirona, Bensheim, Alemanha) e 30 em dissilicato de lítio - IPS e.max CAD (Ivoclar Vivadent Ltda, Schaan, Liechtenstein), nas dimensões 13 x 15 x 1,5 mm. As amostras foram divididas em 6 grupos, com e sem envelhecimento, de forma randomizada: Celtra S – Celtra sem queima; Celtra C – Celtra com queima; E – IPS E.max CAD; Celtra SE – Celtra sem queima e com envelhecimento; Celtra CE – Celtra com queima e com envelhecimento; EE – IPS E.max CAD com envelhecimento. A superfície das cerâmicas foram condicionadas com ácido fluorídrico 5% durante 30 segundos (Celtra Duo) e 20 segundos (IPS e.max), em seguida foi feita a aplicação do agente de união silano Monobond-N (Ivoclar Vivadent, Schaan, Liechtenstein). Para cada bloco, foram confeccionados 6 cilindros de 1 mm de diametro e 2 mm de altura de cimento resinoso para o teste de microcisalhamento. O teste de microcisalhamento foi realizado na máquina de ensaio universal DL 1000 (EMIC, São José dos Pinhais, Paraná, Brasil), com célula de carga de 50 kgf e velocidade de 0,5 mm/min. Os tipos de falhas foram analisados atraves do estereomicroscópico (Microscopia óptica ZEISS MC 80 DX) e microscopio eletrônico de varredura (Jeol-JSM-T330A- Scanning Microscope-Japan). Foi realizado o teste de rugosidade (Ra e Rz) e microscopia eletrônica de varredura (MEV) das superfícies cerâmicas. Os valores de resistência de união (n=10) e rugosidade (n=10) foram submetidos à análise estatística descritiva (média e desvio padrão) e inferencial, mediante o teste paramétrico ANOVA 2-fatores, seguido do teste de Tukey (α=0,05). O teste de microcisalhamento indicou que a condição sem cristalização apresentou resultados superiores aos demais grupos onde mostrou diferença estatisticamente significante (p=0,000). O envelhecimento hidrotérmico foi responsável pela diminuição dos valores de resistência de união para todos os grupos estudados. Conclui-se que o processo de queima de cristalização e degradação hidrotérmica geraram dimunição da resistência adesiva entre esses dois substratos.
This study evaluated the influence of the crystallization firing process and hydrothermal degradation on the bond strength between lithium (di)silicatebased glass-ceramics and resin cement. Ninety ceramic blocks were made: 60 blocks of lithium silicate reinforced by zirconia – Celtra Duo (Dentisply-Sirona, Bensheim, Germany) and 30 blocks of lithium disilicate - IPS e.max CAD (Ivoclar Vivadent Ltd, Schaan, Liechtenstein), in dimensions 13 x 15 x 1.5 mm. The samples were randomly divided into 6 groups, with and without aging: Celtra S – Celtra without burning; Celtra C – Celtra with firing; E – IPS E.max CAD; Celtra SE – Celtra without burning and with aging; Celtra CE – Celtra with burning and aging; EE – IPS E.max CAD with aging. The ceramic surfaces were etched with 5% hydrofluoric acid for 30 seconds (Celtra Duo) and 20 seconds (IPS e.max), then the application of the Monobond-N silane bonding agent (Ivoclar Vivadent, Schaan, Liechtenstein) . For each block, 6 cylinders of 1 mm in diameter and 2 mm in height of resin cement were made for the microshear test. The microshear test was performed in a universal testing machine DL 1000 (EMIC, São José dos Pinhais, Paraná, Brazil), with a load cell of 50 kgf and a speed of 0.5 mm/min. The types of faults were analyzed through stereomicroscopic (optical microscope ZEISS MC 80 DX) and scanning electron microscope (Jeol-JSM-T330A-Scanning Microscope-Japan). The roughness test (Ra and Rz) and scanning electron microscopy (SEM) of the ceramic surfaces were performed. The bond strength (n=10) and roughness (n=10) values were subjected to descriptive (mean and standard deviation) and inferential statistical analysis using the 2-factor ANOVA parametric test, followed by Tukey's test (α= 0.05). The microshear test indicated that the condition without crystallization presented better results than the other groups, where it showed a statistically significant difference (p=0.000). Hydrothermal aging was responsible for the decrease in bond strength values for all groups studied. It is concluded that the crystallization firing process and hydrothermal degradation generated a decrease in the bond strength between these two substrates.
This study evaluated the influence of the crystallization firing process and hydrothermal degradation on the bond strength between lithium (di)silicatebased glass-ceramics and resin cement. Ninety ceramic blocks were made: 60 blocks of lithium silicate reinforced by zirconia – Celtra Duo (Dentisply-Sirona, Bensheim, Germany) and 30 blocks of lithium disilicate - IPS e.max CAD (Ivoclar Vivadent Ltd, Schaan, Liechtenstein), in dimensions 13 x 15 x 1.5 mm. The samples were randomly divided into 6 groups, with and without aging: Celtra S – Celtra without burning; Celtra C – Celtra with firing; E – IPS E.max CAD; Celtra SE – Celtra without burning and with aging; Celtra CE – Celtra with burning and aging; EE – IPS E.max CAD with aging. The ceramic surfaces were etched with 5% hydrofluoric acid for 30 seconds (Celtra Duo) and 20 seconds (IPS e.max), then the application of the Monobond-N silane bonding agent (Ivoclar Vivadent, Schaan, Liechtenstein) . For each block, 6 cylinders of 1 mm in diameter and 2 mm in height of resin cement were made for the microshear test. The microshear test was performed in a universal testing machine DL 1000 (EMIC, São José dos Pinhais, Paraná, Brazil), with a load cell of 50 kgf and a speed of 0.5 mm/min. The types of faults were analyzed through stereomicroscopic (optical microscope ZEISS MC 80 DX) and scanning electron microscope (Jeol-JSM-T330A-Scanning Microscope-Japan). The roughness test (Ra and Rz) and scanning electron microscopy (SEM) of the ceramic surfaces were performed. The bond strength (n=10) and roughness (n=10) values were subjected to descriptive (mean and standard deviation) and inferential statistical analysis using the 2-factor ANOVA parametric test, followed by Tukey's test (α= 0.05). The microshear test indicated that the condition without crystallization presented better results than the other groups, where it showed a statistically significant difference (p=0.000). Hydrothermal aging was responsible for the decrease in bond strength values for all groups studied. It is concluded that the crystallization firing process and hydrothermal degradation generated a decrease in the bond strength between these two substrates.
Descrição
Palavras-chave
Vitrocerâmicas, Adesão, Silicato de lítio, Dióxido de zircônio, Vitroceramics, Adhesion, Lithium silicate, Zirconium dioxide