Propriedades mecanicas e radiodensidade de esmalte, de dentina e de diferentes materiais odontologicos / Mechanical properties and radiodensity of enamel and dentin, and different dental materials

AUTOR(ES)
DATA DE PUBLICAÇÃO

2007

RESUMO

Dental materials development has stimulated the study of their physical and mechanical properties and the substitution of human teeth in dental researches makes necessary the analysis of physical, microstructural and mechanical properties of bovine teeth, varying the age of animals and comparing the results with those from human teeth. In order to fulfill all these requirements this study analyzed: radiodensity and diametral tensile strength of glass ionomer cements; radiodensity of impression materials, zinc phosphate cement and resinous cement, compared to tooth structures; hardness and microstructural characteristics in enamel and dentin from human and bovine teeth, varying bovine teeth age. The results showed that composition is the most important factor affecting radiodensity of materials, being that all evaluated materials presented similar or superior degree of radiodensity than hard dental tissues, but impression materials were generally radioluscent, except for polissulfide ones. Alterations in the powder/liquid ratio negatively affect glass ionomer properties, principally on resin-modified glass ionomers. Age-related changes affect the properties of bovine teeth, but radiodensity is the least influenced property, and hardness is significantly altered. The microstructural analysis showed differences principally between human and bovine enamel, but in spite of the fact that bovine dentin is more similar to human dentin, increasing age of teeth resulted in clear differences. The selection of materials and correct use enables better mechanical and physical properties. The selection of bovine teeth for substitution of human teeth in dental researches must follow important criteria described in this study, being that older bovine teeth showed themselves as possessing a greater similarity to human teeth

ASSUNTO(S)

materiais dentarios dental materials hardness resistencia a tração tensile strenght dureza

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