Evaluating the effects of different beverages with daily consumption habits on the wear of restorative materials

Investigating the Mechanisms of Discoloration in Modern Dental Materials: A Comprehensive Characterization Approach

In general, patients' opinions on reaching ideal esthetics while restoring dental tissues is one of the most important part of the oral treatment. Unfortunately, discoloration of dental materials may occur due to intrinsic and extrinsic factors. The aim of the study was to evaluate the color stability of frequently used dental resin materials and determine the mechanism of their discoloration. The study used various characterization techniques (optical microscopy, Fourier-transform infrared spectroscopy, low-temperature N2 adsorption, diffuse reflectance spectroscopy, and luminescence) to understand the effect of surface defects on discoloration. The adsorption of model liquids on the surface was confirmed to be related to the increase in BET surface area. The study found that the adsorption of discolorants, such as coffee, tea, and wine, on the surface of the dental material follows the multilayer BET model. When the surface is smooth, the discoloration is usually within acceptable limits, with a maximum of ∆E = 3.3. The discoloration made by tea and demineralized water was within acceptable limits even after 7 days of exposure.

Effect of aging and fiber-reinforcement on color stability, translucency, and microhardness of single-shade resin composites versus multi-shade resin composite

OBJECTIVE

The purpose of this study was to evaluate the effect of aging and fiber-reinforcement on the color stability, translucency, and microhardness of single-shade resin composites versus multi-shade resin composite.

MATERIALS AND METHODS

Four resin composites (Filtek Z250, Omnichroma, Vittra APS Unique, Zenchroma) were tested. Three subgroups of specimens were prepared for each of the composites: control, polyethylene fiber-reinforcement, and glass fiber-reinforcement- groups (n = 10/per group). The samples were subjected to aging for 10,000 thermal cycles. Color differences (ΔE00 ) were calculated after aging. Relative translucency parameter (RTP00 ) and microhardness values were calculated before and after aging. A two-way analysis of variance and the generalized linear model was used (p < 0.05).

RESULTS

The lowest and highest ΔE00 values were found for Filtek Z250 (0.6 ± 0.2) and Omnichroma resin composites (1.6 ± 0.4), respectively. The ΔE00 value of the polyethylene fiber-reinforcement group (1.2 ± 0.6) was significantly higher than the ΔE00 value of the glass fiber-reinforcement group (1.0 ± 0.4, p < 0.001). The RTP00 value of the glass fiber-reinforcement group (1.92 ± 0.78) was significantly higher than the RTP00 value of the polyethylene fiber-reinforcement group (1.72 ± 0.77, p < 0.001). The highest microhardness values were found in glass fiber-reinforcement group (76.48 ± 17.07, p < 0.001).

CONCLUSION

Single-shade resin composites were more translucent, had higher color change, and lower hardness than multi-shade resin composite. For relative translucency and microhardness, statistical significance was found in the material and fiber type interaction. The glass fiber-reinforcement provided higher translucency, lower color change and higher microhardness values than polyethylene fiber-reinforcement group after aging. Thermocycling had a significant impact on the color stability, translucency parameter, and microhardness of the tested resin composite materials.

CLINICAL SIGNIFICANCE

Single-shade resin composite materials have greater color-changing potential. The glass fiber-reinforcement optimize resin material mechanical properties and color stability more than polyethylene fiber-reinforcement.

Do universal adhesive systems affect color coordinates and color change of single-shade resin composites compared with a multi-shade composite?

The objective of the study was the impact of universal adhesives on color coordinates and color change of single-shade resin composites compared with a multi-shade composite after thermocycling. Five resin composites (Filtek Z250, Omnichroma, Vittra APS Unique, Zenchroma, and Charisma Diamond One) were used. The composites were randomly divided into three subgroups: two universal adhesive groups (Single Bond and Gluma Bond) and one control group (n=10). Color measurements were performed initially and after 10,000 thermocycling. Color change (ΔE00) values were calculated using the CIEDE2000 formula. The two-way variance analysis was used (p<0.05). The lowest and highest ΔE00 were exhibited in the Filtek Z250 and Charisma Diamond One (p<0.001, p<0.001, respectively). The highest ΔE00 was exhibited in the Gluma Bond (p<0.001). An adhesive system may adversely affect the color change of resin composite materials. L and a values of resin composites decreased, and the b values increased after thermocycling.

Color stability of hybrid ceramics exposed to beverages in different combinations

Background

The aim of this study is to evaluate the color stability of hybrid ceramics stored in different combinations of beverages that are routinely consumed.

Methods

The specimens were prepared with resin nano-ceramic (Lava Ultimate, 3M Espe, USA) and hybrid ceramic (Vita Enamic, Vita Zahnfabrik, Germany). The specimens were aged in a thermocycler machine for 10,000 cycles. They were stored in different combinations of beverages (water, tea, coke, coffee, red wine, pomegranate juice, and turnip juice) for 12 + 12 h. Surface roughness measurements were performed using a profilometer. The specimen colors were measured using a spectrophotometer. The color values (L-a-b) of the specimens and mean surface roughness values (Ra) were recorded at the end of the 1st (D1), 7th (D7), 14th (D14) and 28th (D28) d.

Results

When the solution groups were examined, significant color changes were observed in the Lava coffee-tea, Enamic coffee-tea, Lava coffee-wine, and Enamic coffee-wine groups compared with the other groups (p < 0.01). Except for the samples in the Lava coffee-wine 28th day (D28) and Enamic coffee-wine 28th day (D28) groups, more color changes were observed in the Lava samples than in the Enamic samples across all groups and periods.

Conclusion

Greater color changes (except for the samples stored in coffee-wine) were observed in the Lava samples than in the Enamic samples across all groups and periods. It was observed that the coffee-tea and coffee-wine beverage combinations produced the greatest color change in hybrid ceramics within the limitations of this study.

In Vitro Weight Loss of Dental Composite Resins and Glass-Ionomer Cements Exposed to a Challenge Simulating the Oral Intake of Acidic Drinks and Foods

Specific conditions of the oral cavity, such as intake of acidic drinks, foods, and drugs, represent a damage both for teeth as well as restorative materials. The aim of this in vitro study is to assess the influence of an acidic challenge on the weight loss of biomimetic restorative dental materials (composite resins and glass-ionomer cements, respectively). Seven products recently available in the marked have been tested in this study for the two kinds of materials, respectively. Resin composites were divided into Groups 1A–7A, whereas glass-ionomer cements into Groups 1B–7B. A total of six samples was considered for each group, among which two were stored into distilled water (control samples) whereas the other four were immersed into soft drink (Coca-Cola, Coca-Cola Company, Milano, Italy) for 7 days. Respectively, after 1, 3 and 7 days, weight was assessed for each sample and the percentage weight loss was calculated. For all the composite resins (Groups 1A–7A), no significant intergroup or intragroup differences occurred for the weight loss values (p > 0.05). Conversely, all glass-ionomers (Groups 1B–7B) showed a significant and progressive weight loss after 1, 3, and 7 days of acid challenge (p < 0.05) (intragroup differences). This reduction was significantly lower in case of GC Equia Forte + Coat and ChemFil Rock, with respect to the other cements (p < 0.05) (intergroup differences). In conclusions, all the biomimetic composite resins showed a reliable behavior when exposed to acidic erosion, whereas glass-ionomers cements generally tended to solubilize. However, the additional use of a protective layer above these latter materials could reduce this event. Despite these results appear to be interesting from a clinical point of view, future morphological evaluations should be conducted to evaluate the superficial changes of the materials after acidic explosion.