IADR Abstract Archives

Optical density: microstructure and chemical composition of dental composites

Objective: The aim of this study was to evaluate and compare the microstructure and chemical composition of dental restorative composites, using the technique of scanning electron microscopy (SEM) associated to electron dispersive spectroscopy (EDS), and its influence on optical density. 

Method: Samples of Charisma©(C), Charisma© opaque (CO), Z250©(Z), Durafill©(D), Herculyte© enamel(HE) and Herculyte© dentin(HD), thickness of 1.0 to 4.0mm, had been made using Teflon© matrices with specific diameter. Three radiographies were taken from samples of each material. After development, the optical density of the material images was measured by a transmission densitometer. Five readings were taken from each radiographic image. The values ​​obtained were then subjected to arithmetic mean and the results were expressed as mean optical density values ​​for each material thickness. The samples were recovered (AuPd) for SEM and EDS analysis. Kruskal-Wallis, ANOVA, t test for independent samples and Mann-Whitney test were used to analyze data from the optical density (p<0.05).

Result: The results revealed that D, for all thicknesses, had the highest optical density values compared with the other materials evaluated. HD showed the lowest optical density value for 1.0mm. For 2.0, 3.0 and 4.0mm, Z had the lowest optical density. These results showed statistical significance (p=0,0000). Analysis by EDS revealed the absence of SiO2 in D and the presence of ZrO2 only in Z, suggesting high influence of these compounds on radiographic effect. Analyzing SEM images it was possible to verify differences in size and shape filler for all materials tested. 

Conclusion: Within the limits of the present study it would be concluded that the chemical composition exert high influence on the optical density of the materials evaluated. However the data obtained by SEM were not conclusive when evaluated the influence of size and shape filler on optical density.

Division: IADR/LAR General Session
Meeting: 2012 IADR/LAR General Session (Iguaçu Falls, Brazil)
Location: Iguaçu Falls, Brazil
Year: 2012
Final Presentation ID: 740
Abstract Category|Abstract Category(s): Dental Materials 6: Polymer-based Materials-Chemistry and Composition
Authors
  • Giovannini, José Flávio  ( Centro Universitário Newton Paiva, Belo Horizonte, N/A, Brazil )
  • Castro, Ricardo  ( Centro Universitário Newton Paiva, Belo Horizonte, N/A, Brazil )
  • Brasileiro, Cláudia  ( Universidade Federal de Minas Gerais, Belo Horizonte, N/A, Brazil )
  • Abreu, Mara  ( Universidade Federal de Minas Gerais, Belo Horizonte, N/A, Brazil )
  • Abreu, Mauro H. N. G.  ( UNIVERSIDADE FEDERAL DE MINAS GERAIS, Belo Horizonte, N/A, Brazil )
  • Silveira, Rodrigo  ( Universidade Federal Do Piaui, Teresina, N/A, Brazil )
  • SESSION INFORMATION
    Poster Session
    Photopolymerization and New Approaches to Dental Resins and Composites
    06/21/2012