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

Abstract

Background and aimsTo evaluate the staining effects of two brands of coffee and the bleaching efficiency of two in-office bleaching methods, upon different opacities of a commercial nanocomposite.MethodsTwenty four specimens of each opacity, A3 Dentin, A3 Body and A3 Enamel, were fabricated from Filtek Supreme (3MEspe). The specimens were further divided into two groups (n=12) and were immersed in two coffee solutions (Bio Organic Coffee Bellarom, 100% Arabica, and Iulius Meinl Coffee), for 24 hours. Between the staining sessions, the specimens were stored in sterile water, at 37°C. Each group was further divided into three (n=4), in order to be bleached, as follows: Group 1 - Beyond 35% in office, for 4 applications of 15 minutes each, Group 2 – Zoom Day White 6% in office, for 4 applications of 15 minutes each, Group 3 – Control Group, stored in sterile water. Color values were measured with a dental spectrophotometer Vita EasyShade 4.0 and five measurements were recorded for each sample at a time. Lightness L*, color coordinates a* and b* were recorded, at baseline, after staining in coffee and after bleaching. Whiteness index (WID) of the three composite resins (A3D, A3B, A3E) in the three moments were calculated, as well as the color difference Delta E* correspondent to the staining and bleaching process. Data were analyzed using one-way repeated measures ANOVA and the WID index was calculated WID (p<0.05). Univariate analysis of variance was performed for assessing the influence of staining solution upon composite resins, as well as for testing the effect of bleaching agents. The significance level was set at α=0.05 and pairwise comparisons were adjusted by the Least Significant Difference method.ResultsThe pairwise comparisons showed no significant difference between the effects of the two bleaching agents upon the WID, meaning that they induce almost similar color changes. The results of the univariate ANOVA test indicated a significant effect of the composite resin and the staining solution upon the WID (p<0.05). However, no significant interaction effect was found between the composite resin and the staining solution (p=0.095). There was a significant difference in the staining effect of the two coffee solutions only for A3B and A3E composite resins (p<0.05).ConclusionsThe chromatic changes of the nanocomposite resin could be evaluated by the variation of the whiteness index. The staining effect induced by the two types of coffee was similar. The most effective protocol was the in-office bleaching method based on Beyond 35%.

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

“…Moreover, color stability of resin composites is essential to achieve and maintain acceptable aesthetic goals in direct restorative dentistry. Indeed, by using a spectrophotometer, it may be possible to “translate” the color in coordinates and calculate the staining effects induced by different staining solutions, (e.g., coffee, red wine, tea) [13–15].…”

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

“…These materials are composed of a polymeric matrix based on dimethacrylate monomers and inorganic fillers and are coated with methyl methacrylate-functional silanes to bond the particles to the matrix, as well as a photo-initiator system that permits photoactivation using a light source. 32,[35][36][37][38][39][40][41][42] Most resin-based composites utilize camphorquinone (CQ) as the initiator system. CQ is a stable yellow compound with an unbleachable chromophore group.…”

Effect of an experimental green tea extract bleaching gel on the color changes of a composite resin

“…Since the introduction of the bleaching therapeutic procedures by Haywood and Heyman in 1989 [1], teeth whitening has gained significant acceptance among dental practitioners and patients, both through the simplicity of the procedure and its effectiveness [2].…”

“…The most well-known method of treating tooth discolorations is dental bleaching, performed either by the patient at home under the guidance of the dentist, using prefabricated or customized trays, or in the dental office. The most used substances for tooth bleaching are based on hydrogen peroxide (HP) or carbamide peroxide (PC) [6].…”