Resumos
OBJETIVO: Verificar a resistência à flexão de quatro resinas utilizadas para a confecção de restaurações temporárias submetidas à termociclagem. MÉTODO: Foram utilizadas as resinas da marcas Luxatemp e Structur 2, à base de bisacrilato de metila, e as resinas das marcas Duralay e Alike, à base de metacrilato de metila. Vinte espécimes de cada material foram confeccionados e divididos em dois grupos, para serem submetidos às seguintes condições: (I) - 24 horas de armazenagem em saliva artificial, e (II) - 24 horas de armazenagem em saliva artificial seguida de termociclagem (2000 ciclos, 5 °C-55°C). Cada amostra foi levada ao teste de resistência à flexão em uma Máquina de Ensaios Universal (EMIC DL 10000) e os dados obtidos foram analisados pelo teste ANOVA (dois fatores) e, em seguida, pelo teste Tukey (p < 0,05). RESULTADO: As resinas de bisacrilato apresentaram resultados superiores de resistência à flexão após ambos os tempos de armazenagem, não diferindo estatisticamente entre si após 24 horas (p = 0,3594). A resina Luxatemp apresentou os maiores valores de resistência à flexão após a termociclagem, sendo estatisticamente superior às demais. A termociclagem alterou as propriedades mecânicas de todas as resinas, diminuindo a sua resistência à flexão (p = 0,001). CONCLUSÃO: As resinas de bisacrilato apresentam maior resistência à flexão do que as resinas de metacrilato para os fatores estudados. Todos os materiais utilizados neste estudo tiveram sua resistência reduzida pela ciclagem térmica.
Polimetil metacrilato; prótese parcial temporária; prótese dentária
PURPOSE: This study aimed to evaluate the flexural strength of four resins used for temporary prosthesis after thermo cycling. METHOD: Luxatemp and Structur 2, bis-acryl based resins and, Duralay and Alike, methacrylate based resins, were used. Twenty specimens of each material were confectioned and divided in two groups. The specimens were submitted to the follow conditions: Group I - 24 hours of storage in artificial saliva and, Group II - 24 hours of storage in artificial saliva followed by thermo cycling (2000 cycles, 5 °C-55 °C). Each specimen was carried to flexural strength test in an Universal Testing Machine (EMIC DL 10000) and the results were statistically verified with ANOVA two-way followed by the Tukey test (p < 0.05). RESULT: The flexural strength of bis-acryl based resins was statistically superior to methacrylate based materials after both times of storage; however, they did not differ among themselves after 24 hours (p = 0,3594). The Luxatemp resin presented the higher flexural strength values after thermo cycling, being statistically superior to the others. The thermo cycling process influenced the flexural strength of all the materials evaluated, decreasing their flexural strength (p = 0,001). CONCLUSION: The bis‑acryl resins present superior flexural strength than the methacrylate ones. All materials evaluated have its flexural strength influenced by the thermo cycling process.
Polymethyl methacrylate; denture partial temporary; dental prosthesis
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Datas de Publicação
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Publicação nesta coleção
08 Fev 2013 -
Data do Fascículo
Out 2012
Histórico
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Recebido
06 Ago 2012 -
Aceito
17 Out 2012