Multifactorial analysis of optical properties, sorption, and solubility of sculptable universal composites for enamel layering upon staining in colored beverages

Assessment of Micro-Hardness, Degree of Conversion, and Flexural Strength for Single-Shade Universal Resin Composites

Single-shade universal resin composites (SsURC) are preferred in clinical practice to reduce time for shade selection and obtain good esthetic results. In this study, the static mechanical properties of seven new SsURCs were investigated, their spectral analyzes were performed and scanning electron microscopy (SEM) evaluations were presented. Charisma Diamond One/DO, Admira Fusion x-tra/AFX, Omnichroma/OC, OptiShade/OS, Essentia Universal/EU, Zenchroma/ZC, Vittra APS Unique/VU were used in a three-point bending test to determine flexural strength (FS) and elastic modulus (EM); Vickers micro-hardness (VHN) and hardness-ratio (HR) were performed with a micro-hardness tester from top/bottom after 24-h/15-days of storage in distilled water at 37 °C (±1 °C). The degree of conversion (DC) was assessed by using Fourier transform infrared spectroscopy (FTIR). The structure of the resin matrix and filler content were assessed by SEM. Data were analyzed using IBM SPSS V23 and the R program and the significance level was taken as p < 0.05. The main effect of the tested SsURCs was found to be statistically significant on FS, EM, VHN, and DC values (p < 0.001). Bis-GMA free SsURCs (AFX, DO, VU) showed better DC and HR except for OC. All seven tested SsURCs conform to the requirements of ISO standards for dental resin composites for all tested categories.

Effects of staining and artificial aging on optical properties of gingiva-colored resin-based restorative materials

Objectives

To evaluate CIEDE2000/CIELAB differences in color (ΔE₀₀/ΔE_ab), and translucency parameter (ΔTP₀₀/ΔTP_ab), and gloss of gingiva-colored resin-based restorative materials upon staining/aging.

Materials and methods

Disc-shaped, 10 mm in diameter, and 2-mm-thick samples (n = 5/group) were made from giomer (Beautifil II gingiva), oligomer-based (crea.lign GUM gel), CAD/CAM polymethyl-methacrylate-based (IvoBase CAD), PMMA-based (ProBase Hot), and dimethacrylate-based (SR Nexco Paste Gingiva). Color and gloss were recording using a benchtop spectrophotometer and gloss meter, respectively, at baseline (T0), and upon staining in coffee or red wine for 60 (T1) and 120 h (T2), or artificial aging of 150 kJ/m² (T1) and 300 kJ/m² (T2). Three-way analysis of variance (materials x staining conditions x time intervals), Tukey’s test (α = 0.05), and Pearson’s correlation test were used in analytical statistics.

Results

CIEDE2000 color differences ranged from 1.0 to 4.4 (coffee), 1.5 to 5.3 (wine), and 0.9 to 2.0 after artificial aging, with ΔE₀₀ values being significantly higher for Beautifil than other materials (p < 0.05). ΔTP₀₀ values ranged from 0.2 to 0.7 and were statistically higher upon staining in wine compared to artificial aging (p < 0.05). Gloss values at T0 were 76.7–87.0. Beautifil exhibited the lowest gloss retention (50.8–60.2%) after staining, compared to > 90% of other materials (p < 0.05). ΔE₀₀/ΔE_ab and ΔTP₀₀/ΔTP_ab were positively correlated (p < 0.0001).

Conclusions

Color, translucency, and gloss changes of gingiva-colored restorative materials were material- and staining/aging-dependent. Generally, wine caused greatest changes in color (with IvoBase CAD being the most color stable) and translucency parameter. All materials except Beautifil gingiva II exhibited staining- and aging-dependent gloss retention greater than 90% for all compared time intervals.

Clinical relevance

Optical properties of resin-based gingiva-colored restorative materials depend on material, staining/aging conditions, and exposure time. Certain materials should be avoided in individuals with high consumption of red wine and coffee.

Effects of bioflavonoid-containing mouth rinses on optical properties of tooth-coloured dental restorative materials

This study investigated differences in colour (ΔE₀₀) and translucency parameter (ΔTP₀₀) of nanofilled/microhybrid composites and a glass-ionomer cement following immersion in bioflavonoid (Citrox)- or chlorhexidine-based mouth rinses. Sixty disc-shaped specimens (N = 5/group) of Filtek Supreme (3M), Gradia Anterior (GC) and Fuji IX (GC) were exposed to Citrox/0.2%CHX (Perio+0.2, Curaprox), Citrox/0.09%CHX (Perio+0.09, Curaprox), 0.2%CHX (Savacol, Colgate-Palmolive) or distilled water by 2-min agitation daily for 28 days in an orbital shaker at 200 rpm at 37 °C. Colour recordings were performed using a clinical spectrophometer to obtain CIELab coordinates. General linear model, ANOVA, Tukey test (α = 0.05) and Pearson correlation test were used to analyse data. ΔE₀₀ ranged between 0.33 (Gradia_Savacol_T28) and 6.35 (Fuji_Savacol_T28) (p < 0.001). ΔTP₀₀ ranged between 0.36 (Fuji_ Perio+0.2) and 1.73 (Fuji_Savacol) (p < 0.05). Savacol resulted in higher ΔE₀₀ of Filtek and Fuji and ΔTP₀₀ of Filtek than Perio+0.09 and Perio+0.2 (p = 0.005). Perio+0.09 and Perio+0.2 resulted in higher ΔE₀₀ at T7 than T28 (p < 0.05). There was no correlation between ΔTP₀₀ and ΔE₀₀ (r = 0.445, p = 0.147). Generally, Perio+0.2 and Perio+0.09 mouth rinses produced similar or lower ΔE₀₀ and ΔTP₀₀ than Savacol. GIC Fuji showed higher ΔE₀₀ and similar or higher ΔTP₀₀ than composites Filtek and Gradia. ΔE₀₀ in all materials decreased in Perio+0.2 and Perio+0.09 over time.