Evaluation of chromatic changes of a nanocomposite resin using the new whitness index

Effects of Different Whitening Agents on the Color and Translucency of Different Resin Composites

Objectives

To examine the effects of different whitening agents on the color and translucency of different resin composites, in vitro.

Material and methods

A total of 315 specimens (10.0 ×2.0 mm) were fabricated from two microhybrid (G-aenial anterior [G-Ant]) and (G-aenial posterior [G-Post]) and a nano hybrid (G-aenial A'CHORD [ G-ACH]) resin composites and each group was randomly distributed into seven experimental groups (n=15) as follows; 1- control (C); 2- in-office whitening agent (IOW); 3- at-home whitening agent (AHW); 4- prefilled tray (PT); 5- whitening pen (WP); 6- whitening toothpaste (WT) and 7- whitening mouthwash (WMW). The specimens were subjected to staining except control group before application of the different whitening procedures. The color of specimens was measured after 24 h (T0), after staining (T1) and after whitening (T2). Color change [CIEDE2000 (ΔE00)], translucency parameter (TP) values and changes in whiteness index (WID) were calculated. Data were analyzed statistically (p<0.05).

Results

No significant 𝑊ID differences were detected among the tested resin composites at T0 and T1 (p>0.05), whereas a significant difference was observed at T2 (p<0.005). AHW and IOW produced higher color change than PT, WP, WT and WMR. Significant TP changes were found after the application of IOW and AHW in G-Ant.

Conclusion

The effect of whitening products on the whitening index, color and translucency of resin composites are material and substrate dependent.

Color stability of Lucirin-photo-activated resin composite after immersion in different staining solutions: a spectrophotometric study

INTRODUCTION

Exceptional optical properties characterize teeth. As such, an esthetic restorative material should enable the dental professional to imitate the optical properties of natural teeth accurately. IPS Empress Direct was introduced to the market with the claim that it can mimic optically dental tissues with superior clinical performance.

AIM

To evaluate the ability of IPS Empress Direct to mimic tooth appearance and color and resist staining.

MATERIALS AND METHODS

Three disc specimens were prepared for each shade of enamel and dentin of Lucirin-based composite, IPS Empress Direct (Ivoclar Vivadent) (A1, A2, A3, B1, and B2) (total of 60). The specimens were submitted to colorimetric evaluation in comparison after immersion in 10 different solutions (coffee, coffee with sugar, coffee with milk, red tea, red tea with sugar, red tea with milk, tomato juice, pomegranate juice, coke, and distilled water as a control group) for 4 weeks using spectrophotometric analysis.

RESULTS

After plotting the data and conducting linear regression analyses, IPS Empress showed high potential in mimicking the optical properties of natural tooth color according to the CIE color space. Three solutions showed a change in color higher than 3, coffee, coffee with sugar, and red tea. All other solution showed changes in color that are acceptable clinically.

CONCLUSION

IPS Empress Direct can satisfactory mimic teeth appearance and color while manifesting high stability of color resisting staining upon clinical aging.

Influences of Different Air-Inhibition Coatings on Monomer Release, Microhardness, and Color Stability of Two Composite Materials

The aim of this study was to evaluate the effect of light-curing protocols on two modern resin composites using different air-inhibition coating strategies. This was accomplished by assessing the amount of monomer elution, surface microhardness, and composite discoloration in different storage conditions. A total of 120 specimens were prepared using Filtek Supreme XTE (3M ESPE, Seefeld, Germany) and CeramX Universal (Dentsply DeTrey, Konstanz, Germany). Specimens were light-cured in air as per manufacturer's instructions or in the absence of oxygen. This latter condition was achieved using three different approaches: (i) transparent polyester strip; (ii) glycerin; (iii) argon gas. Specimens were assessed for release of monomers, Vickers hardness, and discoloration after storage in different solutions. The results were analyzed with ANOVA one-way test followed by Student-Newman-Keuls test. Moreover, multiple comparisons of means were performed using the Student t-test (p<0.05). The amount of monomers released from the tested specimens was very low in all conditions. The presence of oxygen induced some decrease in microhardness. The highest discoloration values, for both materials, were obtained after ageing in red wine. In case finish and polish procedures are awkward to achieve in posteriors composite restoration, light-curing in the absence of oxygen should be considered, especially when performing composite restoration in esthetic areas.