Orthodontic shear bond strength to porcelain surface in wet conditions

• Published in: Revista odonto ciência 2016, Vol.31 (2), p.59
• Main Authors: Guimarães, Magáli Beck, Cocco, Bárbara, Bueno, Rodrigo Salbego, Blaya, Micéli Beck Guimarães, Jacques, Letícia Borges, Hirakata, Luciana Mayumi
• Format: Article
• Language: English
• ISSN: 0102-9460; 1980-6523
• DOI: 10.15448/1980-6523.2016.2.16347

Abstract 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.