Estudo da influência das características químicas e microestruturais nas propriedades mecânicas de sistemas totalmante cerâmicos

• Ano de defesa: 2002
• Autor(a) principal: Dias, Alexandre Henrique de Moura [UNESP]
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Estadual Paulista (Unesp)
• Palavras-chave em Português: Materiais dentários; Cerâmicas odontológicas; Prótese dentária; Odontologia - Aspectos estéticos; Dental materials
• Link de acesso: http://hdl.handle.net/11449/110662

The purpose of this study was 10 analyze the influence of chemical and microestrutural characteristics in the mechanical properties of infrastructurematerials (A –IPS Empress 2 and B - ln Ceram Alumina) and of aesthetic revestiment (C –ceramic Empress and D -VltadurA!fa) of systems all ceramic. Inorder to determine the parameters values for mechanical properties involving 4 points flexural oftest in four points were used, shear bond strength (with andwithout cyclic loading) and Vickers superficialmicrohardness. The ceramic surfaces were analyzed trough X-raydiffraction and scanning electron microscopy (SEM). After the mechanical test, the fracture surfaces of the materials A and B andthe interfaces A/C and B/D were analyzed chemically by EDS andmicrostruturally by SEM. The results complied with the literature,where A and B materials consists of crystalline phases and C andD are vitreous.The average flexure fracture strength values were consistenwiththe present compositions in the ceramic and the standard deviations were related to amount of microstrutural defects. Non parametric statistical treatment refering to Kruskal-Wallis and Weibull and involving these e data evidenced a significant difference in the A/C group compared to the remaining materials, and of B/D group compared to Bmaterial. It was not evidenced significant difference between the fracture strength values originated form the test of static shear bond strength and cyclic loading for one same system. ln the test without cyclic loading, evidenced greater adhesive strengthfor the A/C system andthis was associated to the formation of chemical interface