Avaliação qualitativa do efeito de agentes de limpeza na camada de lama dentinária: estudo ultra-estrutural em microscopia eletrônica de varredura
Nenhuma Miniatura disponível
Data
1998-04-01
Autores
ARAÚJO, Maria Auxiliadora Junho de [UNESP]
RODE, Sigmar de Mello [UNESP]
VILLELA, Lauro Cardoso [UNESP]
GONÇALVES, Rogério Duque
Título da Revista
ISSN da Revista
Título de Volume
Editor
Universidade de São Paulo (USP)
Resumo
Quando qualquer instrumento abrasiona ou corta a dentina, produz na superfície uma camada de lama dentinária ou smear layer. Dependendo do agente de união indicado em Odontologia adesiva, há a necessidade ou não da remoção da camada de lama da superfície dentinária. Com a finalidade de verificar a ação de diferentes substâncias para a limpeza dentinária, utilizamos 20 dentes pré-molares superiores íntegros, mantidos em soro fisiológico, nos quais as coroas foram seccionadas ao meio no sentido mésio-distal. Com instrumento diamantado, removeu-se o esmalte da porção vestibular e da porção lingual da coroa e, com uma broca carbide cilíndrica lisa nº 56, cortou-se aproximadamente 1 mm de dentina com alta rotação sob abundante refrigeração ar/água, para produzir a camada de lama dentinária. em seguida, essa superfície foi tratada com diferentes substâncias e lavada por 30 segundos com spray ar/água. No controle, foi simplesmente utilizado o spray ar/água. Os espécimes foram montados em suportes metálicos, preparados e visualizados no MEV-DSM 950 da Zeiss, em aumentos que variaram de 100 a 5.000 vezes. Os materiais que mais removeram a camada de lama foram, em ordem crescente: 1. spray ar/água; 2. fluoreto de sódio 2%; 3. associação alternada de Dakin/Tergensol; 4. água oxigenada 3%; 5. jateamento com óxido de alumínio 50 mm; 6. flúor acidulado 1,27%; 7. ácido poliacrílico 25%; 8. ácido fosfórico 10%.
A smear layer is produced on the dentin surface after abrasion or cutting by instruments. Its removal is indicated or not according to the kind of bonding agent used in adhesive dentistry. The purpose of this study was to evaluate the possible effects of some substances on the smear layer. Twenty upper non-carious premolars, stored in isotonic saline solution, were mesiodistally hemi-sectioned and the buccal and lingual enamel was removed with high speed diamond bur. One millimeter of the dentinal surface was then removed with a water-cooled high speed carbide bur # 56 in order to obtain the smear layer. Different solutions were applied on the dentin surface for 30 seconds, which was then rinsed and dried. The specimens were mounted on metallic holder stubs, prepared, and examined under the scanning electron microscope (DSM 95-Zeiss). Removal of the smear layer by the tested solutions was qualitatively observed, and the solutions, rated according to their performance in increasing order of extent of removal, as follows: 1. air/water spray; 2. 2% NaF; 3. sodium hypochloride/anodic detergent; 4. 3% H2O2; 5. sandblasting with 50 mm aluminum oxide; 6. 1.27% acidulated fluoride; 7. 25% polyacrylic acid; 8. 10% phosphoric acid. The best solutions for the removal of the smear layer were the acid ones.
A smear layer is produced on the dentin surface after abrasion or cutting by instruments. Its removal is indicated or not according to the kind of bonding agent used in adhesive dentistry. The purpose of this study was to evaluate the possible effects of some substances on the smear layer. Twenty upper non-carious premolars, stored in isotonic saline solution, were mesiodistally hemi-sectioned and the buccal and lingual enamel was removed with high speed diamond bur. One millimeter of the dentinal surface was then removed with a water-cooled high speed carbide bur # 56 in order to obtain the smear layer. Different solutions were applied on the dentin surface for 30 seconds, which was then rinsed and dried. The specimens were mounted on metallic holder stubs, prepared, and examined under the scanning electron microscope (DSM 95-Zeiss). Removal of the smear layer by the tested solutions was qualitatively observed, and the solutions, rated according to their performance in increasing order of extent of removal, as follows: 1. air/water spray; 2. 2% NaF; 3. sodium hypochloride/anodic detergent; 4. 3% H2O2; 5. sandblasting with 50 mm aluminum oxide; 6. 1.27% acidulated fluoride; 7. 25% polyacrylic acid; 8. 10% phosphoric acid. The best solutions for the removal of the smear layer were the acid ones.
Descrição
Palavras-chave
Camada de esfregaço, Preparo da cavidade dentária, Dentina, Microscopia eletrônica de varredura, Smear layer, Dental cavity preparation, Dentin, Microscopy, electron, scanning
Como citar
Revista de Odontologia da Universidade de São Paulo. Universidade de São Paulo, v. 12, n. 2, p. 99-104, 1998.