Measurement of the optical density of packable composites: comparison between direct and indirect digital systems

Abstract

The aim of this study was to measure the optical density of four packable composite resins with widths of 1, 2, 3 and 4 mm, by means of Digora (direct) and DentScan DentView (indirect) digital imaging systems, in order to compare both methods. Twenty acrylic plates, with the proposed thicknesses, were used, each one containing a sample of each resin. Each acrylic plate was radiographed three times, under a standardized technique. For the Digora system, an optical plate was used under each resin sample, and, for the DentScan DentView system, occlusal films were employed, totalizing 60 exposures for each system. Optical plates and films were scanned and three consecutive optical readouts were carried out, totalizing 1,440 readouts. The results were submitted to statistical analysis and revealed that the average optical density of the four resins always increased as thickness increased. Regarding the comparisons between the composite resins, in both analysis the resin with the greater optical density was Surefil followed by Prodigy Condensable, Alert and Solitaire . The correlations between the results of Digora and DentScan DentView were significant for the different thicknesses and materials. The observed tendency is that as the values obtained with the Digora system increase, so do the values obtained with DentScan DentView . While thickness increased, the values of optical density in both Digora and DentScan DentView tended to approach each other. The Digora system presented smaller amplitude between the results obtained in adjacent thicknesses.

Comparison of conventional and digital radiography systems with regard to radiopacity of root canal filling materials

“…All endodontic filling materials had higher radiopacity values on digital images regardless of their composition. Similarly, comparing the optical density values of composite resins using Digora SPP images and digitized films, Graziottin et al (2002) reported that Digora images had higher and more homogenous radiopacity values. This difference may be attributed to the different image acquisition technologies of digital image receptors.…”

“…2008). Additionally, indirectly digitized radiographs tend to have higher variation of the grey level, as read‐out depends on the specific characteristics of the scanner (Graziottin et al. 2002).…”

“…In digital The radiopacity of root canal filling materials Akcay et al International Endodontic Journal, 45, 730-736, 2012 ª 2012 International Endodontic Journal systems, output of the measurements is stored as absolute numbers of available grey shades (from 0 to 255) in contrast to the continuous density curve in the analogue film image (Baksi et al 2008). Additionally, indirectly digitized radiographs tend to have higher variation of the grey level, as read-out depends on the specific characteristics of the scanner (Graziottin et al 2002). Therefore, direct digital imaging would reduce the loss of information that should occur with the use of indirect digitalization (Gü rdal & Akdeniz 1998).…”

Radiopacity of endodontic materials using two models for conversion to millimeters of aluminum

“…29 Digital cameras require adjusting of the radiographic and zooming distance 28 of the camera; this can cause distortion of the image, depending on the values chosen for the photographic parameters, such as diaphragm aperture, exposition time and sensor sensibility. 29 In addition, radiographic images obtained by the indirect technique tend to exhibit a higher gray level variation, because the variability of grayscale values depends on the specific characteristics of the scanner 30 or photographic camera used.…”

Comparação Termográfica Facial E Da Eficiência Mastigatória De Pacientes Que Apresentam DTM Associada À Sintomatologia Dolorosa E Pacientes Saudáveis: Revisão De Literatura

“…No presente estudo foram utilizadas cartelas tipo blíster de fundo reto para a confecção dos corpos de prova, a fim de que a espessura dos mesmos fosse padronizada para os três materiais, evitando assim que a espessura interferisse nos resultados. A espessura utilizada foi de 2,0 mm, considerando que à medida que a espessura do material aumenta, há uma maior produção de valores de densidade óptica (GRAZIOTTIN et al, 2001;GRAZIOTTIN et al, 2002…”