Search Results (93)

Hydrogels are versatile biomaterials for controlled drug delivery and tissue regeneration due to their biocompatibility and tunable degradation. Hydrogel was synthesized with a gelatin type A/polyvinyl alcohol functionalized with aqueous extract of roasted green tea (10% w/v) and evaluated its physiobiological performance in vitro. Degradation was assessed under enzymatic (collagenase II, trypsin) and hydrolytic conditions; swelling was performed with distilled water, cytocompatibility was tested on human periodontal ligament stem cells by MTT; antibacterial activity was measured against Streptococcus mutans, Staphylococcus aureus, and Escherichia coli. The hydrogel showed complete hydrolytic degradation within 60 min and enzymatic degradation within 70 min, the hydrogel increased its mass by approximately 6.3 times relative weight, reached its maximum swelling in the range of 478–537%, (19% for the experimental group), while maintaining PDLSC viability (>80%). It exhibited significant antibacterial activity (inhibition: S. aureus 78.6%, S. mutans 67.4%, E. coli 73.2%). Importantly, in osteogenic medium, the hydrogel enhanced osteogenic differentiation of PDLSCs, evidenced by increased calcium deposition and positive Alizarin Red staining versus controls. These data position the gelatin/PVA/roasted green tea hydrogel as a bioactive, resorbable candidate for dental applications—particularly as an antimicrobial dressing and adjunct for periodontal bone regeneration material. Full article

Light-curing gingiva-colored composite resins (GCCs) are widely used for their esthetics and versatility, although they remain susceptible to discoloration. This in vitro study evaluated the effect of GCC thickness on color stability under different staining solutions and immersion times. Four hundred specimens were fabricated with a 3D-printed resin (P Pro; Institut Straumann AG), incorporating circular intaglio areas of varying thicknesses (0.2, 0.4, 0.6, 0.8, and 1.0 mm), into which paste (Nexco; Ivoclar AG) or flowable (Gradia Gum; GC Corp) GCCs were applied. After artificial aging in water at 55 °C for 5 days, specimens were immersed in coffee, black tea, red wine, or distilled water (control). Color differences (ΔE₀₀) were assessed using digital photocolorimetry (eLAB protocol) and the CIEDE2000 formula at 2.5, 5, and 7 days. Data for each consistency were analyzed with 3-way repeated measures ANOVA and Tukey HSD (α = 0.05). Thicker GCCs (0.6–1.0 mm) showed significantly greater discoloration (p < 0.05). Flowable GCCs were more prone to color changes induced by coffee (p < 0.05), whereas paste GCCs exhibited more discoloration with black tea (p < 0.05). Extended immersion time increased color change, particularly in flowable GCCs. Overall, GCC thickness, immersion duration, and material consistency influenced long-term color stability. Full article

Follicular development is recognized as a highly complex biological process regulated by multiple factors. Thyroid hormone (TH) is considered one of the key regulators of female reproduction, and its dysregulation can significantly impair follicular development. Epigallocatechin gallate (EGCG), the main active component of green tea, possesses strong antioxidant properties. Numerous studies have demonstrated that EGCG positively influences reproductive function in both humans and animals. However, whether EGCG directly affects follicular development under conditions of TH dysregulation remains poorly understood. The primary objective of this study was to investigate the impact of hyperthyroidism on ovarian development, examine whether EGCG could mitigate the adverse effects of TH dysregulation, and elucidate the underlying molecular mechanisms. In the T₄-induced hyperthyroidism rat model, ovarian tissues were serially sectioned for Hematoxylin-Eosin (HE) and Masson’s trichrome staining to assess morphological changes, and follicle numbers were quantified at each developmental stage. Granulosa cell (GC) viability, proliferation, and apoptosis induced by T₃ were evaluated using CCK8, EdU, and TUNEL assays, respectively. Antioxidant enzyme activity was measured, and the expression levels of related proteins were analyzed via Western blotting. Results showed that hyperthyroidism altered ovarian structure, significantly increasing the number of atretic follicles. Levels of antioxidant enzymes, including Superoxide Dismutase (SOD), Glutathione Peroxidase (GSH-PX), and Catalase (CAT), were markedly decreased, whereas the lipid peroxidation product malondialdehyde (MDA) was significantly elevated. Furthermore, all ERS-related proteins, phosphorylated Eukaryotic Initiation Factor 2 Alpha (p-eIF2α), Activating Transcription Factor 4 (ATF4), C/EBP homologous protein (CHOP), and Caspase-3, were upregulated, accompanied by decreased glucose-regulated protein 78 (GRP78) expression. Treatment with EGCG alleviated these detrimental effects of hyperthyroidism. At the cellular level, high concentrations of T₃ reduced GC viability and proliferation while increasing apoptosis. Reactive oxygen species levels were elevated, and GRP78 expression was decreased. Notably, all T₃-induced effects were reversed by EGCG treatment. In summary, this study demonstrates that hyperthyroidism induces oxidative stress in GCs, which triggers endoplasmic reticulum stress via the eIF2α/ATF4 pathway and leads to apoptosis. EGCG mitigates apoptosis by enhancing antioxidant capacity, thereby preserving ovarian function. These findings establish EGCG as a protective agent for maintaining ovarian health and fertility. Full article

This study aimed to evaluate how acidic and alkaline staining solutions affect the optical properties (mean color change, ΔE*), geometric characteristics (surface roughness, Ra), and bacterial adhesion of zirconia Ceramill Zolid PS computer-aided design/computer-aided manufacture (CAD/CAM) material after 21 days of immersion. Ninety-six zirconia CAD/CAM Ceramill Zolid multilayer PS specimens were prepared and allocated to eight groups based on the pH values of the immersion solutions; the acidic solutions included Mirinda Citrus, CodeRed, yerba mate tea, Saudi coffee, and Nescafe (A–E), and the alkaline solutions included artificial saliva, DZRT (tobacco-free nicotine pouches), and smokeless tobacco (F–H). The specimens were immersed for 21 days at 37 °C, with the solutions replaced every 12 h to ensure consistency. Color changes were measured using a VITA Easyshade V spectrophotometer, and Ra was evaluated via white-light interferometric microscopy. The bacterial adhesion of Streptococcus mutans was quantified by counting colony-forming units (CFUs, CFU/mm²). Statistical analyses included the Shapiro–Wilk test for normality, one-way ANOVA with Tukey’s HSD post hoc test for group comparisons, and paired t-tests, with significance set at <0.05. The recorded pH values of the staining materials ranged from acidic (Mirinda Citrus: 3.23) to alkaline (smokeless tobacco: 8.54). Smokeless tobacco caused the most unacceptable mean color change (ΔE* = 6.84), followed by DZRT (ΔE* = 6.46), whereas artificial saliva produced the least discoloration (ΔE* = 2.15), with statistically significant differences among the solutions (p < 0.001). The Ra measurements varied significantly (p < 0.001), with Nescafe demonstrating the lowest value (0.486 µm) and DZRT the highest (0.748 µm). S. mutans adhesion was the highest for CodeRed (546.75 CFU) and the lowest for smokeless tobacco (283.92 CFU), demonstrating significant variation across groups (ANOVA, p < 0.001). The acidic and alkaline solutions significantly altered the optical properties, Ra, and bacterial adhesion of zirconia Ceramill Zolid PS CAD/CAM, with acidic solutions leading to higher bacterial adhesion. Full article

Gingivitis is a common and reversible inflammatory condition caused by dental plaque accumulation, which, if left untreated, can progress to periodontitis. Conventional oral care products like chlorhexidine (CHX) and fluoride are effective in plaque control but are often associated with adverse effects such as dental staining and mucosal irritation. This systematic review aimed to compare the efficacy and safety of natural versus conventional toothpastes and mouthwashes in managing plaque-induced gingivitis. The review followed PRISMA guidelines and was registered in PROSPERO (No. 1008296). A systematic search was conducted across PubMed, Web of Science, and Scopus for English-language clinical studies published between 2015 and 2025. Eligible studies included randomized controlled trials and clinical trials on human subjects with plaque-induced gingivitis. Exclusion criteria were studies on animals, in vitro experiments, review articles, and studies lacking control groups. Data extracted included intervention type, sample characteristics, clinical indices (PI, GI, SBI), inflammatory biomarkers, adverse events, and patient adherence. A narrative synthesis was conducted due to study heterogeneity. Fifteen studies were included. Natural products such as neem, green tea, aloe vera, and propolis demonstrated comparable effectiveness to CHX and fluoride in reducing gingival inflammation and plaque indices, with a lower incidence of side effects. In particular, natural formulations showed superior tolerability and better patient compliance, especially in long-term use. However, variability in concentration and the formulation of natural products limits their clinical standardization. In conclusion, natural oral care products appear to be effective and better-tolerated alternatives to conventional agents in managing gingivitis. Nonetheless, further long-term, standardized clinical trials are needed to confirm their efficacy and define optimal formulations. Full article

Biomimetic restorative dentistry aims to preserve tooth structure and achieve optimal aesthetic harmony with surrounding dentition. The principles and protocols associated with biomimetic restorative dentistry are designed to enhance the longevity of the restoration. The use of flowable CRs is increasingly common; however, the effect of viscosity on the discoloration has not been clearly established. This in vitro study aimed to assess the color stability of flowable CRs with varying viscosities following immersion in common staining solutions and subsequent repolishing. A total of 250 disc-shaped specimens (8 mm × 2 mm) were prepared from five CRs with different viscosity profiles: high-viscosity (Spectra STHV, Dentsply, Milford, DE, USA), medium-viscosity (Estelite Universal Flow Medium, Tokuyama Dental Co., Tokyo, Japan), bulk-fill (Estelite Bulk-Fill Flow, Tokuyama Dental Co., Tokyo, Japan; SDR Plus, Dentsply, Milford, DE, USA), and packable (Estelite Posterior, Tokuyama Dental Co., Tokyo, Japan). After polymerization and baseline color measurements, specimens were immersed in coffee, tea, cola, red wine, or distilled water for 144 h. Color values were recorded before and after staining, and again following repolishing. Color changes (ΔE₁, ΔE₂, ΔE₃) were calculated using the CIE Lab system and statistically analyzed via two-way ANOVA and Tukey HSD (α = 0.05). Both the CR type and the staining solution substantially affected the color change. SDR Plus exhibited the highest ΔE values. Red wine caused the most discoloration. Repolishing enhanced color in selected groups. Full article

Dancong tea is a representative type of oolong tea typically stored for over six months before sale to reduce gastrointestinal irritation. The effects and mechanisms of this storage on gastrointestinal damage remain unclear. Therefore, this study investigated hydrochloric acid and ethanol (HCl/EtOH)-induced gastric injury in mice. The results indicate that six-month-stored Dancong tea (OldT) alleviated gastric injury at low doses but showed no protective effect at high doses; in fact, high-dose OldT exacerbated injury. In contrast, fresh tea (NewT) aggravated gastric injury at both low and high doses. Hematoxylin and eosin (H&E) staining revealed that low-dose OldT significantly attenuated gastric histopathological injury. Mechanistically, low-dose OldT reduced injury via antioxidant and anti-inflammatory pathways (Nrf-2/HO-1 activation and NF-κB inhibition), and inhibiting lipid peroxidation, reactive oxygen species (ROS), nitric oxide (NO), and inflammatory mediators (iNOS, COX-2, IL-6, TNF-α). These findings suggest that storage reduces the gastrointestinal irritant properties of fresh Dancong tea, providing a scientific basis for industrial practice and guiding consumption. Full article

Background: Early caries management is essential to enable reversal of white spot lesions without the further need for operative interventions, especially in primary dentition. Silver-based compounds can be quite effective in arresting caries lesions; however, a major drawback is teeth staining. This study aimed to evaluate the remineralization potential and aesthetic effects of novel, green-synthesized nano-silver fluoride (NSF) on artificial white spot lesions in primary teeth in comparison to 38% silver diamine fluoride (SDF) and silver diamine fluoride/potassium iodide (SDF/KI). Materials and Methods: NSF was synthesized using green tea extract. Sixty primary teeth specimens with artificial enamel lesions were randomly divided into five groups depending on the applied material: 38% SDF, 38% SDF/KI, single and double application of NSF, and control group. Treatments were followed by pH cycling. Surface microhardness and photographic analysis were conducted to assess remineralization and staining. Statistical analysis was conducted using non-parametric tests including Kruskal–Wallis and Mann–Whitney U tests with Bonferroni correction. Results: The greatest increase in microhardness was observed in the group receiving double NSF application. Its remineralizing potential was comparable to that of 38% SDF/KI, with no statistically significant difference (p = 1.000). Importantly, NSF-treated samples exhibited no teeth discoloration, unlike the black staining observed in SDF and SDF/KI groups. Conclusions: Green-synthesized NSF is a promising alternative to conventional SDF and SDF/KI, offering remineralization benefits without compromising aesthetics. The eco-friendly formulation and non-staining properties support its potential for clinical use in pediatric dentistry. Full article

The complex chemical composition of certain color stains on textiles requires an optimal proportion of thermal and chemical action in the Sinner cycle of the washing process. In this study, both factors were analyzed by varying the composition of the liquid detergent, bleach, and ozone at temperatures of 30 °C, 40 °C, 60 °C, 75 °C, and 90 °C. Standard cotton fabrics stained with tea, red wine, and blood/milk/ink were selected as monitors, which were evaluated before and after the washing process by spectral parameters. The data sets and their interrelationships were evaluated by a cluster analysis (CA) and ANOVA. An unstained standard cotton fabric was selected as a reference for qualification of the sanitation effect. The stain removal effects showed a selective influence of ozone in the washing processes under the investigated conditions, including the synergy of standard materials—stain monitors and different Sinner cycle factors. The most effective sanitation was achieved in processes using formulations with higher concentrations of liquid detergent (D) and bleaching agents (BA) across all tested temperatures. A lower ozone concentration in combination with lower concentrations of detergents and bleaching agents in washing processes at 30 °C and 40 °C also contributed positively to the effect on sanitation. Full article

Caffeic acid (CA) is a naturally occurring polyphenol antioxidant found in coffee, tea, fruits, and vegetables, known for its strong antioxidant, anti-inflammatory, and anti-aging properties. However, its cosmetic application is limited because of poor dermal absorption due to its high polarity. This study aimed to evaluate the antioxidant and skin-brightening effects of a novel lipophilic CA derivative, CAD (caffeic acid-3,4-dihydroxyphenylpropanolester). CAD was synthesized by conjugating CA with 3,4-DHPEA, a lipophilic antioxidant derived from olive oil. In both DPPH and ABTS assays, CAD exhibited more potent antioxidant activity than CA. In B16F10 melanoma cells, CAD significantly inhibited melanin production without cytotoxicity at concentrations lower than those required for CA. Cellular assays using DCF-DA staining demonstrated that CAD effectively reduced intracellular ROS levels. Mechanistic studies revealed that CAD inhibited tyrosinase activity and downregulated the expression of TYR, TRP-1, and TRP-2. Additionally, CAD suppressed MITF phosphorylation, along with reduced phosphorylation of ERK and JNK, elucidating its anti-melanogenic mechanism. Importantly, CAD showed dose-dependent skin-brightening effects in the 3D human skin model Melanoderm™, as evidenced by increased lightness and histological evaluation. In conclusion, CAD demonstrates strong potential as a safe and effective antioxidant and skin-brightening agent for cosmetic applications. Full article

To explore the taste characteristics and flavor characteristics of Baiyun 0492 white tea, Fuyun 6 was used as a comparison to describe and analyze the taste of the tea by the standard tea sensory evaluation method and quantitative descriptive analysis. A total of 1083 nonvolatile metabolites were identified by ultrahigh-performance liquid chromatography and mass spectrometry (UPLC–MS–MS). N-Feruloyl tyramine, with strong biological activity, may be the specific metabolite of Baiyun 0492 white tea, and 3,4,5-tricaffeoylquinic acid, with a bitter taste, may be the specific metabolite of Fuyun 6 white tea. Most of the different metabolite contents were negatively correlated with the Baiyun 0492 and Fuyun 6 white tea grades. KEGG metabolic pathway analysis showed that Baiyun 0492 and Fuyun 6 white teas had higher enrichment levels of flavonoids, caffeine, amino acids and carbohydrate-related metabolic pathways. Correlation analysis using widely targeted metabolomics and quantitative taste description showed that most flavonoid differences and some amino acid and phenolic acid differences were significantly positively correlated with bitterness and astringency, including quercetin-3-o-rhamnoside (quercetin), L-arginine, 3,4,5-tricaffioylquinic acid, and neochlorogenic acid. Some soluble sugars were positively correlated with sweetness, including D-maltose and D-sucrose, which were the key taste components of Baiyun 0492 and Fuyun 6. These metabolites may be responsible for the taste characteristics of Baiyun 0492, which is characterized as sweet and mellow, while the taste of Fuyun 6 is mainly mellow. In this study, a wide range of targeted metabolomics techniques were used to screen out different metabolites related to the quality of Baiyun 0492 and Fuyun 6 white teas, providing a reference for clarifying the quality characteristics of Baiyun 0492. Full article

Background: Rapid on-site evaluation (ROSE) is crucial for improving the diagnostic yield of fine-needle aspiration (FNA) biopsies. Despite recent advances in ROSE, such as telecytology, the rapid stains used in this process have not seen significant innovation. Diff-Quik (DQ) and Toluidine Blue (TB), the most common ROSE stains, have significant limitations. This study evaluates the optimized Toluidine Blue stain, a mixture of Toluidine Blue, Eosin, and Alcohol (TEA), as a potential alternative to TB or DQ for ROSE. Methods: A comparative study was conducted using fifty remnant body fluid specimens with adequate cellularity, collected at the University of California Davis Medical Center over six months. Two smears were prepared from each specimen. One was stained with TB, and the other with optimized Toluidine Blue (TEA). Digital images of each slide were evaluated by three cytologists and two cytopathologists, blinded to the stain, using five criteria: background staining, cytoplasmic detail, nuclear membrane clarity, chromatin texture, and nucleoli staining. Each criterion was scored on a scale of 1 to 3. Results: Optimized Toluidine Blue (TEA) stain demonstrated superior overall image quality compared to TB. Specifically, optimized Toluidine Blue (TEA) showed significantly less background staining (p < 0.05) and improved nuclear membrane clarity (p < 0.05), chromatin texture (p < 0.05), and nucleoli detail (p < 0.05). There was no significant difference between the two stains in the assessment of cellularity or cytoplasmic detail. Conclusions: The optimized Toluidine Blue (TEA) stain shows promise as a rapid stain for ROSE, offering rapid processing and improved digital image quality. Further evaluation of optimized Toluidine Blue (TEA) stain on FNA specimens is warranted to validate these findings and explore its potential to enhance telecytology in ROSE. Full article

Staining removal is an issue of interest in dentistry. Current treatments deal with staining removal on enamel, while few studies concentrate on resin composites. The aim of the current study is to evaluate the efficacy in staining removal of an ozonated gel on dental composites. The study sample consisted of 40 specimens of restorative composites: 20 specimens were stained for 1 day in tea solution (tea group) and 20 specimens were stained for 1 day in physiological solution (NaCl group). Both the tea and NaCl groups underwent the experimental treatment as follows: five specimens underwent ozonized gel application, five specimens underwent an ozonized spray, five specimens underwent an application of olive oil, and five specimens were not treated. A colorimetric evaluation was performed with a spectrophotometer, using CIEDE2000 data elaboration at the baseline (T0), after staining (T1), and after staining removal (T2). In the T0–T1 time frame, significantly different color changes (ΔE₀₀) were found between tea groups and NaCl groups (p < 0.05), except for control groups (p > 0.05). After staining removal in the T1–T2 period, no significant differences in ΔE₀₀ were found (p > 0.05). Higher values were found for groups treated with ozonized gel, denoting a stain removal effect. The groups treated with olive oil, instead, exhibited higher ΔE₀₀ values, showing a greater staining effect. In conclusion, the ozonized gel tested showed staining removal activity on restorative resin composites. Future clinical applications are required to validate the in vitro results obtained. 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

The aesthetics of clear aligners is a critical factor that can influence patient satisfaction and psychological and social well-being. However, their transparency can be compromised by exposure to staining agents. This study aimed to evaluate the color stability of PET-G aligners following prolonged exposure to common daily substances, including food, tobacco products, and cleaning agents. Flat samples of PET-G (n = 220) were immersed in various solutions, including coffee, tea, Coca-Cola, red wine, a colloidal silver-based disinfectant, nicotine, artificial saliva, cigarette smoke, and mixtures of saliva with smooth, coffee, and nicotine. Immersion times of 10 (n = 110) and 15 days (n = 110) were randomly assigned. Colorimetric assessments were conducted by measuring L*a*b* parameters before and after immersion, and total color change (ΔE) was calculated. Non-parametric statistical tests revealed significant color changes in PET-G samples after both immersion durations, with pairwise comparisons indicating notable differences in ΔE values among groups exposed to different substances, particularly coffee, tea, and Coca-Cola. The findings highlight the psychological and social impact of aligner staining on patient confidence and compliance. Understanding these effects highlights the need for enhanced patient education to improve aligner aesthetics and satisfaction. Full article