Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2009;107:e65-e69
Objective: The purpose of this study was to determine the ideal concentration of bismuth oxide in white Portland cement to provide it with sufficient radiopacity for use as an endodontic material (ADA specification #57).Study design: 2-mm thick standardized test specimens of white MTA and of white Portland cement, as controls, and of white Portland cement with the experimental addition of 5%, 10%, 15%, 20%, 25% or 30% of bismuth oxide were radiographed and compared with various thicknesses of pure aluminum, using optic density to determine the observed grayscale levels of radiopacity in a scale ranging from 0 to 255. The data was submitted to ANOVA (p0.05) and the Ryan-Einot-Gabriel-Welch and Quiot test (REGWQ) for multiple comparison of the means.Results: White Portland cement with 0%, 5%, 10%, 15%, 20%, 25% and 30% of bismuth oxide presented mean readings of 63.3, 95.7, 110.7, 142.7, 151.3, 161.0 and 180.0 respectively. MTA presented a mean reading of 157.3.The readings of MTA and white Portland cement with 15% bismuth oxide did not differ significantly from the reading observed for a thickness of 4 mm of aluminum (145.3), which is considered ideal for a test specimen by ADA specification #57 (2 mm above the thickness of the test specimen).Conclusion: White MTA and white Portland cement with 15% bismuth oxide presented the radiopacity required foran endodontic cement.
Carlos Eduardo da Silveira Bueno, Eduardo Gregatto Zeferino, Luiz Roberto Coutinho Manhães, Jr., Daniel Guimarães Pedro Rocha, Rodrigo Sanches Cunha e Alexandre Sigrist De Martin
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