Orthodontic shear bond strength to porcelain surface in wet conditions

• Autor(a) principal: Guimarães, Magáli Beck
• Data de Publicação: 2016
• Outros Autores: Cocco, Bárbara, Bueno, Rodrigo Salbego, Blaya, Micéli Beck Guimarães, Jacques, Letícia Borges, Hirakata, Luciana Mayumi
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Revista odonto ciência (Online)
• Texto Completo: https://revistaseletronicas.pucrs.br/ojs/index.php/fo/article/view/16347
• topic: Shear strength; Dental porcelain; Dental bonding; Orthodontics; Resistência ao cisalhamento; Porcelana dentária; Colagem dentária; Ortodontia

Objective: To evaluate the shear bond strength of orthodontic accessories bonded to a porcelain surface after storage in water.Methods: One-hundredand-twenty feldspathic porcelain discs were divided into 4 groups, according to the surface treatment: Group 1 – 37% phosphoric acid etching; Group 2 – 10% fluorhydric acid; Group 3 – 37% phosphoric acid and silane application; Group 4 – 10% fluorhydric acid and silane application. After the accessories were bonded, the sample was divided into two subgroups, according to the time interval of storage in distilled water: Control – 24 hours; and Test – 150 days. Shear bond strength was determined using a universal test machine, and failure type was verified by scanning electron microscopy.Results: In the test groups there was reduction in shear bond strength, particularly when silane was used. Test Groups 2 and 4 presented shear bond strength values within those proposed as adequate for orthodontic bonding. Groups 1 and 3  presented adhesive failures between porcelain and resin, whereas in Groups 2 and 4 cohesive failures in porcelain were recorded.Conclusion: Storage in water for 150 days decreased the bond strength at silanized interfaces. Fluorhydric acid etching generates adequate bond strength in wet conditions, however, increases the fracture rate in porcelain.