ABSTRACT
Statement of the Problem: Optical properties of the composite resins, concerning their translucency and thickness, are affected by discolored tooth structure or inherent darkness of the oral cavity
Purpose: This study aimed to compare the translucency parameter [TP] of five different composite resins in different thicknesses and to evaluate their masking ability in black backgrounds
Materials and Method: Five brands of composite resins; Gradia [GC] and Crystalline [Confi-dental] in opaque A2 [OA2], Vit-l-escence [Ultradent] in opaque snow [OS], Herculite XRV [Kerr] and Opallis [FGM] in dentin A2 [DA2] shades were selected to enroll the study. Color coordinates of each composite were determined at 0.5, 1, and 1.5 mm thicknesses on a white backing, the backing of material itself and a black backing were calculated by using a spectrophotometer to evaluate the translucency parameter [TP] of the study materials. The masking ability was also calculated from the specimens on the material itself and on black backing. The values under 2 were estimated as imperceptible. One-way ANOVA, T-test and Tukey HSD were employed for statistical analysis
Results: The masking ability values, recorded for the 1.5 mm-thick specimens, were in the range of imperceptible except for the Herculite. There was no difference in TP values of the materials at 1.5 mm thickness. Opaque snow shade of Vit-l-escence and opaque A2 shade of Gradia showed lower TP values in comparison with the other 1 and 0.5 mm-thick materials and this difference was statistically significant [p< 0.05]
Conclusion: In relatively thin thicknesses [
ABSTRACT
One of developments in field of radiology is providing the radiographic image based on computed radiography [CR] system. Common usable capabilities of CR system are obtaining super BW [Bite-Wing] images from digital panoramic views. Considering advantages of this system such as edge enhancement, we decided to evaluate the agreement of super BW with digital intraoral BW which is produced with PSP [Phosphor Storage Plate] system in detection of proximal caries. In this study, 40 patients with bilateral BW produced by intraoral PSP sensor [Digora Optime] and digital panoramic radiography which was taken with cassette containing storage plate [Konica Minolta] were selected. First, two super BWs were extracted from digital panoramic images of the patients and then proximal caries in digital intraoral BW and super BW images were evaluated by two different observers separately. In this study, the agreement between two methods was evaluated for each observer with kappa agreement test. After analysis of data, it was revealed that there was a moderate agreement between two methods in detection of caries by first and second observers [0.454, 0.421]. There was a poor agreement for detection of proximal caries of premolar teeth and a moderate agreement about molar teeth between first and second observers. Interobserver agreement for both techniques was good [0.664, 0.626]. According to the findings of this study, it seems that due to a good agreement between two observers and a moderate agreement between two techniques about detection of caries, the use of super BW method instead of intraoral BW technique is not proper and therefore, using digital intraoral BW in detection of dental caries is preffered