Search Results (85)

Background/Objectives: Maxillofacial silicone prostheses’ long-term color stability remains a challenge. This study aimed to evaluate and compare the color stability of conventional and digital maxillofacial silicone elastomers mixed with nano-sized antimicrobial additives (ZnO nanoparticles and chlorhexidine salt-CHX) at various concentrations over a 10-week period. Methods: A total of nine groups (n = 10) of maxillofacial silicone elastomers were prepared. These included a control group (no additives), conventionally pigmented silicone, digitally pigmented silicone (Spectromatch system), and silicone mixed with ZnO or CHX at 1%, 3%, and 5% by weight. Specimens were fabricated in steel molds and cured at 100 °C for 1 h. Color measurements were performed at baseline and after 1, 4, 6, and 10 weeks using a Minolta Chroma Meter (CIELAB system, ΔE₀₀ formula). Data were analyzed using two-way ANOVA and Tukey HSD post hoc tests (α = 0.05). Results: Color changes (ΔE₀₀) ranged from 0.74 to 2.83 across all groups. The conventional pigmented silicone group showed the highest color difference (ΔE₀₀ = 2.83), while the lowest was observed in the ZnO 1% group (ΔE₀₀ = 0.74). Digital silicone and all antimicrobial-modified groups exhibited acceptable color stability (ΔE₀₀ < 3.1). Time significantly affected color difference, with the largest change occurring during the first four weeks (p < 0.05), followed by stabilization. Regression analysis confirmed high color stability over time for all groups except the conventional pigmented group. Conclusions: This is one of the first studies to directly compare digital and conventional pigmentation methods combined with nano-antimicrobials in maxillofacial silicones. Maxillofacial silicone elastomers mixed with up to 5% ZnO or CHX maintained acceptable color stability over 10 weeks. Digital pigmentation is similar to conventional methods. The incorporation of nano-antimicrobials offers significant microbial resistance and improved color retention. Full article

In this in vitro study, we compare the discoloration potential of three premixed calcium silicate cements, specifically EndoCem MTA Premixed, Bio-C Repair, and NeoPUTTY, when applied with or without two surface pretreatments (Nd-YAG laser irradiation or dentin-bonding agents). One hundred extracted human maxillary incisors were allocated into ten groups (n = 10), including the untreated control group. A standard access cavity was prepared in all teeth except the control group. Groups were formed according to the type of premixed calcium silicate cement used and the surface pretreatment applied to the internal surfaces of the cavities. Color measurements were taken with a VITA Easyshade Advance 5.0 spectrophotometer and converted to ΔE values using the CIEDE2000 formula at baseline (T0) and 7 (T1), 30 (T2), 90 (T3), and 180 (T4) days. Data were analyzed using the Shapiro–Wilk test to assess normality, followed by the Friedman and Kruskal–Wallis tests for within- and between-group comparisons, respectively (α = 0.05). No statistically or clinically significant differences in ${∆\mathrm{E}}_{00}$ were detected among materials, surface treatments, or timepoints (p > 0.05). All mean ${∆\mathrm{E}}_{00}$ values remained below the perceptibility threshold (3.5). Within the limitations of this 180-day in vitro model, the tested materials showed favorable short-term color stability, and neither the Nd-YAG laser nor the dentin-bonding agents altered the outcomes. Long-term in vivo studies are required to recommend their clinical use in aesthetically critical areas. Full article

This study evaluated the effects of conventional cigarette smoke compared to aerosol from a heat-non-burn tobacco product on the color stability of two UDMA-based dental composite resins, namely a monochromatic (Omnichroma) and a polychromatic (Vittra APS) resin. Twenty disc-shaped specimens were prepared, divided into two groups of ten, and exposed to 105 cigarettes or 105 aerosol tobacco sticks via a custom-made smoking chamber. Puff duration was 2 s, with a 60 s interval between puffs in which smoke saturated the chamber for 30 s; then, clean air was introduced into the chamber for 30 s. Six puffs and six intervals were simulated. Color parameters were measured before and after exposure and following brushing of each specimen with 15 strokes. Color differences were determined based on the CIEDE2000 formula. Significant color change was found in all specimens exposed to cigarette and tobacco aerosol. The highest color-change mean value was obtained from composite resin exposed to cigarette smoke. Although both cigarette and thermal heating systems cause discoloration, the aerosol causes reduced composite resin discoloration, which compromises aesthetics and increases patient dissatisfaction, impacting the overall dental care. Color stability is the hallmark of success, as it is the main reason for replacing dental restorations. Full article

Tooth bleaching is a widely used esthetic treatment; however, bleaching agents can temporarily alter the surface morphology of enamel, increasing surface roughness and porosity, which may lead to increased susceptibility to discoloration. This in vitro study investigated the effectiveness of fluoride varnish in preventing immediate discoloration of bovine incisors after bleaching. Specimens were bleached with 35% hydrogen peroxide and treated with either Clinpro White Varnish (CW) or Enamelast Fluoride Varnish (EN), whereas control specimens received no treatment after bleaching. The samples were immersed in coffee for 24 h, and the color difference (ΔE₀₀) was calculated using the CIEDE2000 formula. The surface morphology of enamel was examined using SEM. The fluoride varnish groups showed significantly lower color difference values than the control group (p < 0.05), with ΔE₀₀ reduced by approximately two-thirds in both the CW and EN groups. SEM observations showed that the enamel surfaces in the varnish-treated groups exhibited reduced surface irregularities compared to the untreated group, suggesting remineralization. These results suggest that the immediate application of fluoride varnish after bleaching can effectively reduce short-term discoloration by providing physical protection and promoting remineralization. Fluoride varnish may serve as a simple and effective strategy to maintain whitening outcomes and minimize early discoloration. Full article

Background/Objectives: Tooth bleaching is a widely requested aesthetic procedure in modern dentistry. However, the structural effects of high-concentration peroxide-based bleaching agents on enamel remain insufficiently understood. This study aims to evaluate and compare the effects of three in-office bleaching agents—Opalescence Boost (40% hydrogen peroxide [HP]), Opalescence Quick (45% carbamide peroxide [CP]), and BlancOne Ultra + (35% hydrogen peroxide [HP])—on enamel surface characteristics and color change using confocal laser scanning microscopy (CLSM) and spectrophotometric analysis. Methods: Forty-two extracted human teeth were sectioned and divided into experimental and control halves. Each experimental specimen underwent bleaching according to the manufacturer’s protocol. Color measurements were conducted at baseline, immediately post-treatment, at 3 days, 7 days, and 6 months following treatment using the Vita Easyshade^® spectrophotometer. Color differences were calculated using the CIEDE2000 (ΔE₀₀) formula. Enamel surface morphology was assessed by CLSM. Data were analyzed using Wilcoxon and Kruskal–Wallis tests (p < 0.05), performed with SPSS v23. Results: All bleaching agents produced clinically perceptible color changes (ΔE₀₀ > 3.3). Opalescence Boost achieved the highest and most consistent whitening effect (mean ΔE₀₀ > 11), while Opalescence Quick showed moderate efficacy (ΔE₀₀ ~6–8), and BlancOne Ultra+ induced milder changes (ΔE₀₀ ~4–5). CLSM imaging revealed surface alterations in all bleached samples, with more pronounced changes observed in specimens treated with higher peroxide concentrations. Conclusions: All three bleaching systems were effective in improving enamel color, with Opalescence Boost delivering the most substantial and durable effect. CLSM analysis confirmed morphological changes in enamel without evidence of severe damage. These results underscore the importance of selecting bleaching protocols that balance efficacy with enamel safety. Further in vivo studies are recommended to validate long-term structural effects and support clinical decision-making. Full article

The aim was to assess the blending effect of universal-shade resin-based composites (RBCs) (Omnichroma—OC; Clearfil Majesty Universal–CM; Venus Pearl—V; Transcend—T) used for repair for lithium disilicate blocks. Fifteen parallelepiped-shaped (10.5 × 10.5 × 3 mm) specimens with four cavities (3 mm in diameter and 2 mm in depth) were designed from lithium disilicate CAD/CAM blocks (CEREC Tessera HT A3) and milled. Specimens were then randomly divided into five groups based on the five resin composite materials for cavity restoration (n = 12): Group 1, control group (F); Group 2 (T); Group 3 (OC); Group 4 (V); and Group 5 (CM). After surface conditioning, composite resins were applied to the ceramic surface. Color measurements were taken with a colorimeter in the center of the resin restoration and on the CAD/CAM block. Tristimulus values were converted to CIELab color coordinates and color differences were expressed in ΔE₀₀ units using the CIEDE-2000 formula. F showed significantly better color matching (ΔE₀₀ = 2.51 ± 0.64) in comparison to single-shade RBCs except T (ΔE₀₀ = 2.55 ± 0.64). All groups exceeded perceptibility and acceptability thresholds. The control group presented higher color matching than the single shade universal composites except for Transcend. Full article

This study investigates the impact of dynamically adjusting the potassium-to-calcium ratio (molar ratio) in nutrient solutions used on cherry tomatoes at different growth stages (seedling, flowering and fruit setting, and maturity) to enhance fruit appearance, nutritional quality, and mineral content. By focusing on the ‘Saopolo’ variety, 17 treatments were implemented, each involving a specific potassium-to-calcium ratio in the nutrient solutions applied during the seedling, flowering and fruit setting, and fruiting stages. The aim was to optimize the nutrient solution formula and enhance fruit quality. Fruit quality parameters were assessed at the initial maturity stage across various treatments, encompassing commodity quality (fruit stalk length, fruit shape index, and fruit hardness), taste quality (total soluble sugar, titratable acid content, and sugar-acid ratio), nutritional quality (vitamin C (Vc), soluble protein, and lycopene content), antioxidant quality (total phenol and flavonoid content), as well as comprehensive quality (soluble solids content). Principal component analysis was conducted on these parameters. Additionally, mineral element levels in fruits were analyzed at different developmental stages (white ripe, color transition, and mature stages). When tomato plants were treated with nutrient solutions containing varying potassium-to-calcium ratios at different growth stages, observations revealed distinct outcomes in the first fruit cluster. T15 (seedling stage (A): 0.5 times standard nutrient solution; flowering and fruit-setting stage (B): potassium-to-calcium = 1.6:1; fruiting stage (C): potassium-to-calcium = 2.1:1) exhibited the highest fruit firmness (1.54 kg·cm⁻²), while T14 (A; B (K:Ca = 1.6:1); C (K:Ca = 2.0:1)) elevated levels of total soluble sugars (6.59%), titratable acidity (0.74%), soluble proteins (2.79 mg·g⁻¹), and total phenolics (2.56 mg·g⁻¹). T13 (A; B (K:Ca = 1.6:1); C (K:Ca = 1.9:1)) demonstrated superior soluble solids (5.9%), lycopene (32.09 µg·g⁻¹), and flavonoid contents (0.77 mg·g⁻¹), whereas T12 (A; B (K:Ca = 1.6:1); C (K:Ca = 1.8:1)) showcased the highest sugar–acid ratio (12.63) and soluble solids content (5.9%). Notably, T8 (A; B (K:Ca = 1.5: 1); C (K:Ca = 1.9:1)) exhibited the highest Vc content (10.03 mg·100 g⁻¹). Mineral element analysis indicated that an increased potassium-to-calcium ratio in the nutrient solution during various growth stages enhanced phosphorus and potassium uptake by the fruits but hindered the absorption of nitrogen, calcium, magnesium, and iron. In summary, employing half the standard nutrient solution dosage during the seedling stage, utilizing a potassium-to-calcium ratio of 1.6:1 in the nutrient solution at the flowering and fruit setting stage, and applying nutrient solution T13 with a potassium-to-calcium ratio of 1.9:1 during the fruit-bearing phase, optimally coordinates fruit nutrient accrual and enhances flavor quality. These findings support the use of stage-specific nutrient modulation to improve cherry tomato quality in controlled-environment agriculture. Full article

In general, the acceptance of edible insects by consumers is low. Therefore, the aim of this research was to develop protein supplements from desiccated crickets. The objectives of this research were to study the effects of four different drying methods on the chemical properties of crickets and the effects of cricket powder fortification in vegetable chips on the chemical and physical qualities and consumer acceptance. Through an analysis of the chemical composition of cricket powder dried using hot air, vacuum, microwave, and freeze-drying methods, it was found that freeze-drying resulted in the highest protein content in the cricket powder, followed by vacuum drying, hot air drying, and microwave drying. However, the antioxidant activity, which was analyzed using DPPH, showed no significant differences across the four drying methods (p > 0.05). The sensory testing of chips by 30 consumers revealed that the chips with a 10:10 ratio of vegetable powder to cricket powder received the highest satisfaction results in all of the test attributes, ranging from “like” to “like very much”. When studying the chemical composition, hardness, and color of the chips, it was found that increasing the amount of cricket powder resulted in a decrease in lightness and yellowness, while redness and hardness increased. The antioxidant activity and phenolic content of the chips increased with the addition of cricket powder, while the flavonoid and potassium contents decreased as vegetable powder was replaced with cricket powder. In the formula most preferred by consumers, the antioxidant activity, phenolic content, flavonoid content, and potassium content were 60.90%, 6.25 ± 0.46 mg GAE/mg sample, 11.16 ± 0.1 mg QE/mg sample, and 0.66 ± 0.01%, respectively. Full article

Purpose: The aim of this study was to evaluate the color stability of 3D printed resin disks using spectral reflectance data obtained at different time periods after immersion in various staining solutions. The color stability of 3D-printed temporary crowns is clinically important, as it directly affects the esthetic outcome and patient satisfaction during the provisional phase of treatment. Materials and methods: Forty identical round disk specimens measuring 10 mm in diameter and 2 mm in thickness were fabricated using CAD/CAM 3D printing resin (shade B1). Half of the specimens (n = 20) were polished using an acrylic bur and medium pumice. The remaining specimens were unpolished (n = 20). Each group of disks was then immersed in one of the following immersion solutions: artificial saliva, black tea, carrot juice, and red wine. Color difference ΔE was evaluated using the spectrophotometer, a spectral reflectance instrument, at baseline, day 1, week 1, week 2 and week 3, against a white background. Comparisons between polished and unpolished disks at each time point were conducted using Mann–Whitney tests. Differences among the staining solutions at each time point for both polished and unpolished disks were analyzed using a one-way ANOVA with Tukey’s post hoc test. Results: Color difference ΔE was measured using the CIELAB formula. The mean ΔE values of each group were calculated. The greatest difference in color was observed in the unpolished and polished disks immersed in red wine. Polished disks showed less color difference when compared to unpolished disks. Significant differences in ΔE were detected between polished and unpolished disks immersed in red wine at week 1 (p = 0.0159), week 2 (p = 0.0079) and week 3 (p = 0.0079) and in carrot juice at week 3 (p = 0.0317). Conclusions: Immersion of 3D printed disks in different staining solutions caused detectable color difference in the tested materials, which was relative to the immersion duration and the staining solution used. The color of the 3D printed resins is influenced by the surface finishing, which may result in visually perceptible color differences. The color stability of 3D printied materials should be improved to provide long-term esthetics. Full article

Most dyeing occurs when a fabric is in a wet state, while color matching is performed when the fabric is in a dry state. As water is a colorless liquid, it has been difficult to analytically map these two states using existing color theories. Machine learning models provide a heuristic approach to this class of problems. Linear regression, random forest, eXtreme Gradient Boosting (XGBoost), and multiple neural network models were constructed and compared to predict the color of dry cotton fabric from its wet state. Different models were developed based on squeeze pressure (water pickup), with inputs to the models consisting of the L*a*b* (L*: lightness; a*: red–green axis; b*: blue–yellow axis) coordinates in the wet state and the outputs of the models consisting of the predicted L*a*b* coordinates in the dry state. The neural network model performed the best by correctly predicting the final shade to under a 1.0 color difference unit using the International Commission on Illumination (CIE) 2000 color difference formula (CIEDE2000) color difference equation about 63.9% of the time. While slightly less accurate, XGBoost and other tree-based models could be trained in a fraction of the time. Full article

Background: A brief resolved unexplained event (BRUE) is a brief, sudden episode occurring in infants younger than 1 year of age, characterized by some combination of absent, decreased, or irregular breathing, an altered level of responsiveness, color change, and change in muscle tone. Although inappropriate feeding has been suggested as playing a role in the occurrence of BRUEs, only anecdotal reports have been described. The main objective of our study was to objectively evaluate whether overfeeding may represent a risk factor for the occurrence of BRUEs. Methods: We enrolled 42 infants aged 0–6 months and admitted for BRUE episodes and the same number of age- and sex-matched healthy infants who served as controls. Data about feeding practices and auxological parameters of each enrolled infant were collected and analyzed, along with clinical data about the pre- and post-natal period. The primary outcome measures were mean daily body weight gain, daily number of feedings, mean volume of feedings, and average daily volume only for bottle-fed infants. Results: The mean (±SD) daily body weight gain, the only available and reliable parameter to assess feeding adequacy in both breast- and formula-fed infants, was 41 ± 15 g in infants with BRUEs vs. 35 ± 11 g in healthy infants (95% CI [0.21; 11.8], p = 0.042). Moreover, infants with BRUEs were more likely to receive mixed breastfeeding than controls, although this difference did not reach statistical significance (33% vs. 17%, 95 CI [−0.04; 0.37], p = 0.131). Conclusions: Overfeeding seems to be a risk factor for BRUEs, either through milk inhalation, choking, or GER worsening. Detecting inappropriate feeding practices and providing appropriate education may help prevent the BRUE produced by either scenario. Full article

History aside, traditional mayonnaise faces a rising animal welfare concern dietary approach and remains dependent on cold environments throughout the supply chain due to food safety. Nowadays, consumers are able to find alternative formulas from vegetable sources with relevant emulsifying capacity. However, sensory characteristics may differ from the traditional expected product. A mixed system composed of the innovative ingredient heterotrophic white Chlorella vulgaris and a disruptive emulsifier, yeast protein extract (YPE), was assessed to transform traditional coriander mayonnaise into an analog product. The effect of pH and salt (NaCl) content was also evaluated. The mixed system depicts a promising stability since the average Sauter diameter of both is similar (7.94 μm and 7.49 μm), also observed in the unimodal droplet size distribution. Viscoelastic behavior has slightly different responses for the plateau model (278.951 Pa and 252.053 Pa), while increasing the salt content reflects an approximation regarding firmness (0.059 N and 0.057 N) and adhesiveness (0.372 N.s and 0.361 N.s). Introduction of microalgae increases bioactivity, mainly TPC (+118.84 ugGAeq/g) and antioxidant activity—RSA (+31.29 ugTEAC/g) and FRAP (+35.26 ugTEAC/g). Despite the color deviation, the sensorial analysis of both products enlightened the absence of major perception. Full article

Inorganic/organic composite passivation film can significantly improve the corrosion resistance performance of hot-dip Al-Zn-coated steel. However, yellowing of the passivation film always leads to obvious performance degradation in corrosion resistance. Investigating the yellowing mechanism of the passivation film and its impact on corrosion resistance would provide a foundation for enhancing its yellowing resistance property. This study primarily focuses on the yellowing mechanism of the passivation film based on the copolymer of N-vinylpyrrolidone and N-vinylcaprolactam. It is found that the oxidation and semi-carbonization of butyramide and valeroamide generated by C–N bond cleavage in the copolymer at high temperatures are responsible for the yellowing of the passivation film. The cracking of the passivation film caused by yellowing degree exposes more of the bare Al-Zn coating, further accelerating the degradation in the corrosion resistance. Additionally, it is observed that the impact of yellowing on the corrosion resistance is negligible when the color difference (ΔE*) caused by yellowing is less than 3.0, whereas ΔE* values above 3.0 result in rapid degradation in the corrosion resistance of the passivation film. The formula y = 0.77 − 0.07x + 0.023x² + 0.0039x³ effectively expresses the relationship between corrosion area (y) and ΔE* (x) (R² = 0.995). Full article

In Thailand, wild yam, or Dioscorea hispida Dennst., is a starchy crop that is usually underutilized in industry. The purpose of this study was to isolate the starch and extract the phytochemical from D. hispida and use them in cosmetics. Starch was used instead of talcum, which can cause pulmonary talcosis in dusting powder formulas (DP 1-5). GC-MS was used to identify the bioactive components present in the ethanolic extract of D. hispida. The main compounds were identified as 9,12-octadecadienoic acid (Z,Z)- (6.51%), stigmasta-5,22-dien-3-ol, (3.beta.,22E)- (6.41%), linoleic acid ethyl ester (5.72%), (Z,Z)-9,12-octadeca-dienoic acid, 2,3-dihydroxy-propyl (3.89%), and campesterol (3.40%). Then, the extract was used as an ingredient in facial sleeping mask gel formulas (SM 1–SM 5). Stability tests, physical characteristics, enzyme inhibitions, and sensitization dermal toxicity tests were used to evaluate the DP and SM formulations. The results showed that the fresh tubers of D. hispida showed a 12.5% w/w starch content. The findings demonstrated that starch powder had a restricted size distribution, ranging from 2 to 4 μm, and a smooth surface that was polygonal. Following stability testing, the color, odor, size, and flowability of all DP formulations did not significantly differ. The SEM investigation revealed that DP particles were homogenous. For the sensitization dermal toxicity test, DP denoted no erythema or skin irritation in the guinea pigs. After stability testing, the colors of the SM formulas were deeper, and their viscosity slightly increased. The pH did not significantly change. After the stability test, SM formulas that contained Glycyrrhiza glabra and D. hispida extracts exhibited stable tyrosinase and elastase inhibitory activities, respectively. In the sensitization dermal toxicity test, guinea pigs showed skin irritation at level 2 (not severe) from SM, indicating that redness developed. All of these findings indicate that D. hispida is a plant that has potential for use in the cosmetics industry. Furthermore, D. hispida starch can be made into a beauty dusting powder, and more research should be conducted to develop an effective remedy for patients or those with skin problems. Full article

The excavation of the Lieshan Kiln site represents a significant advance in the field of ceramic archaeology. Previous scholars fixated on the white porcelain unearthed from this kiln, yet this study zeroed in on celadon from the Northern Song and Jin Dynasties. Celadon samples were analyzed using colorimetry, energy-dispersive X-ray fluorescence spectroscopy (ED-XRF), scanning electron microscopy (SEM), polarizing microscopy, X-ray photoelectron spectroscopy (XPS), and thermal expansion analysis. Results revealed that material and technological advancements in the production of the Lieshan Kiln and reveal the special phase-separated structure in the glaze of the transparent celadon, with a weakly reduced firing atmosphere. Celadon bodies from both periods were crafted from local sedimentary clays in a single-ingredient formula, with the Jin Dynasty refining the preparation, leading to enhanced density and higher firing temperatures compared to the Northern Song Dynasty. The celadon glaze, a high-calcium type made up of glaze ash and specific clays, differed from the body materials. The high SiO₂/Al₂O₃ molar ratio, along with Fe₂O₃ and trace P₂O₅, promoted phase separation. Glaze coloration was modulated by the interaction of Fe³⁺ and Fe²⁺ ions, and chemical coloration by Fe ions prevailed when phase-separated particles were minute enough to avoid Rayleigh or Mie scattering. In conclusion, the study deepens the understanding of ancient ceramic production by exploring the phase separation structure and coloring mechanism of the celadon. Full article