Avaliação de silicones para próteses faciais em função do efeito do tempo de armazenagem, da desinfecção química e da pigmentação sobre a deterioração marginal e a dureza Shore A
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Data
2006-12-20
Autores
Guiotti, Aimée Maria [UNESP]
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Editor
Universidade Estadual Paulista (Unesp)
Resumo
O insucesso das próteses faciais é causado pelas limitações das propriedades dos materiais existentes, sendo as mais críticas a flexibilidade e a durabilidade. Uma prótese facial deve ser resistente e ter longa duração, mas se manter suave e flexível para acompanhar os movimentos faciais do paciente. Diante destas considerações, o objetivo desta pesquisa foi o de avaliar a deterioração marginal e a dureza SHORE A de dois silicones para uso em prótese facial - o Silastic 732 R.T.V. e o Silastic MDX4-4210, sob a influência do tempo de armazenagem, da desinfecção diária com clorexidina a 2% e de dois tipos de pigmentação, considerando que sempre houve a necessidade de um material que combinasse a flexibilidade natural da pele humana com durabilidade no seu uso. Foram confeccionados 30 corpos-de-prova para cada material, divididos em 3 grupos: controle (incolor), pigmentados com maquiagem e com óxido de ferro. A análise da deterioração marginal foi realizada em microscópio eletrônico de varredura e o teste de dureza dos materiais foi realizado em durômetro SHORE A, imediatamente, 6 meses e um ano após a confecção dos corpos-de-prova, seguindo as especificações da ASTM. Os dados da dureza foram submetidos à análise estatística, utilizando-se do teste de Tukey com nível de 99% de confiabilidade. Os dois silicones para uso facial apresentaram um aumento da sua dureza SHORE A com o passar do tempo. Entretanto, a dureza SHORE A manteve-se estável no período de 6 meses a 1 ano. Quando os silicones foram comparados entre si, o Silastic 732 R.T.V. mostrou-se estatisticamente mais flexível que o MDX4-4210. Após a análise visual das fotomicroscopias (aumento de 1000x) foi possível perceber que todos os grupos sofreram deterioração marginal e alteração de sua textura superficial com o passar do tempo...
Prosthetic failure can be attributed to the inherent problems of the properties of materials, such as flexibility and durability. The maxillofacial prosthesis must be strong and have durability, but must be soft and flexible enough to respond to the facial motions of the patient. The purpose of this study was to analyse the influence of time s storage, chemical disinfection with 2% chlorhexidine-based solution and two distincts pigments about marginal deterioration and SHORE A hardness of two silicones for use in maxillofacial prosthesis - the Silastic 732 R.T.V. and the Silastic MDX4-4210. Thirty specimens were fabricated for each silicone using a matrix. Specimens were separated in three groups: control (colourless), pigmented with commercial cosmetic (makeup powders) and pigmented with iron oxid. The marginal deterioration analysis was realized in scanning electron microscope (SEM) and the hardness test was realized in a SHORE A durometer, according to ASTM, designation D 2240. The readings were realized after polymerization of the specimens (initial period), after 6 months and 1 year, with and without disinfection. The data of SHORE A hardness were submited to the statistic analysis, by the Tukey s Test. Both silicones presented an increase of hardness over time. However, the hardness maintained stable at 6 months and 1 year periods. When both silicones were compared, the Silastic 732 R.T.V. showed statistically softer than MDX4-4210. After visual analysis of photomicrocopies (1000x), was possible note that all groups suffered marginal deterioration over time. The chemical disinfection also contributed to marginal deterioration of silicones, independent of time and pigmentation. Subject to the design, materials and methods used in this research, the following conclusions can be drawn:...(Complete abstract, click electronic address below)
Prosthetic failure can be attributed to the inherent problems of the properties of materials, such as flexibility and durability. The maxillofacial prosthesis must be strong and have durability, but must be soft and flexible enough to respond to the facial motions of the patient. The purpose of this study was to analyse the influence of time s storage, chemical disinfection with 2% chlorhexidine-based solution and two distincts pigments about marginal deterioration and SHORE A hardness of two silicones for use in maxillofacial prosthesis - the Silastic 732 R.T.V. and the Silastic MDX4-4210. Thirty specimens were fabricated for each silicone using a matrix. Specimens were separated in three groups: control (colourless), pigmented with commercial cosmetic (makeup powders) and pigmented with iron oxid. The marginal deterioration analysis was realized in scanning electron microscope (SEM) and the hardness test was realized in a SHORE A durometer, according to ASTM, designation D 2240. The readings were realized after polymerization of the specimens (initial period), after 6 months and 1 year, with and without disinfection. The data of SHORE A hardness were submited to the statistic analysis, by the Tukey s Test. Both silicones presented an increase of hardness over time. However, the hardness maintained stable at 6 months and 1 year periods. When both silicones were compared, the Silastic 732 R.T.V. showed statistically softer than MDX4-4210. After visual analysis of photomicrocopies (1000x), was possible note that all groups suffered marginal deterioration over time. The chemical disinfection also contributed to marginal deterioration of silicones, independent of time and pigmentation. Subject to the design, materials and methods used in this research, the following conclusions can be drawn:...(Complete abstract, click electronic address below)
Descrição
Palavras-chave
Protese maxilo-facial, Silicones, Prótese Maxilofacial, Desinfecção, Maxillofacial prosthesis, Silicones, Disinfection
Como citar
GUIOTTI, Aimée Maria. Avaliação de silicones para próteses faciais em função do efeito do tempo de armazenagem, da desinfecção química e da pigmentação sobre a deterioração marginal e a dureza Shore A. 2006. 219 f. Tese (doutorado) - Universidade Estadual Paulista, Faculdade de Odontologia de Araçatuba, 2006.