Search Results (10)

In this study, we present novel, vitrimeric and biobased scaffolds that are designed for hard tissue applications, composed of acrylated, epoxidized soybean oil (AESO) and reinforced with bioactive glass that is Tellurium doped (BG-Te) and BG-Te silanized, to tune the mechanical and antibacterial properties. The manufacture’s method consisted of a DLP 3D-printing method, enabling precise resolution and the possibility to manufacture a hollow and complex structure. The resin formulation was optimized with a biobased, reactive diluent to adjust the viscosity for an optimal 3D-printing process. The in vitro biological evaluation of the 3D-printed scaffolds, combined with BG-Te and BG-Te-Sil, showed that the sample’s surfaces remained safe for hBMSCs’ attachment and proliferation. The number of S. aureus that adhered to the BG-Te was 87% and 54% lower than on the pristine (control) and BG-Te-Sil, respectively, with the eradication of microbiofilm aggregates. This work highlights the effect of the vitrimeric polymer matrix and doped, bioactive glass in manufacturing biocompatible, biobased, and antibacterial scaffold used in hard tissue application. Full article

Candida albicans (C. albicans) adhering to denture-based resins (DBRs) is a known cause of denture stomatitis. A new approach to prevent denture stomatitis is to include antimicrobial substances within DBRs. Here, we examined the mechanical performance and antifungal properties of DBRs containing benzyldimethyldodecyl ammonium chloride (C₁₂BDMA-Cl) as an antimicrobial compound. C₁₂BDMA-Cl is a quaternary ammonium compound, and its antifungal properties have never been investigated when combined with dental acrylic resin. Therefore, we modified a commercially available heat-polymerized acrylic DBR to contain 3 and 5 wt.% of C₁₂BDMA-Cl. Unmodified DBR was used as a control group. Specimens were prepared using the conventional heat processing method. The specimen’s flexural strength, elastic modulus, microhardness, and surface roughness were evaluated. C. albicans biofilm was grown on the specimens and assessed via colony-forming units (CFUs) and scanning electron microscopy (SEM). In silico molecular docking was applied to predict the potential C₁₂BDMA-Cl inhibition activity as an antifungal drug. The 3% C₁₂BDMA-Cl DBR demonstrated antifungal activities without a deterioration effect on the mechanical performance. SEM images indicated fewer colonies in DBR containing C₁₂BDMA-Cl, which can be a potential approach to managing denture stomatitis. In conclusion, C₁₂BDMA-Cl is a promising antifungal agent for preventing and treating denture stomatitis. Full article

The colonisation of the surface of removable acrylic dentures by various types of microorganisms can lead to the development of various diseases. Therefore, the creation of a bioactive material is highly desirable. This study aimed to develop a denture base material designed to release bioactive ions into the oral environment during use. Four types of bioactive glasses (BAG)—S53P4, Biomin F, 45S5, and Biomin C—were incorporated into the PMMA acrylic resin, with each type constituting 20 wt.% (10 wt.% non-silanised and 10% silanised) of the mixture, while PMMA acrylic resin served as the control group. The specimens were subsequently immersed in distilled water, and pH measurements of the aqueous solutions were taken every seven days for a total of 38 days. Additionally, surface roughness and translucency measurements were recorded both after preparation and following seven days of immersion in distilled water. The cytotoxicity of these materials on human fibroblast cells was evaluated after 24 and 48 h using Direct Contact and MTT assays. Ultimately, the elemental composition of the specimens was determined through energy-dispersive X-ray (EDX) spectroscopy. In general, the pH levels of water solutions containing BAG-containing acrylics gradually increased over the storage period, reaching peak values after 10 days. Notably, S53P4 glass exhibited the most significant increase, with pH levels rising from 5.5 to 7.54. Surface roughness exhibited minimal changes upon immersion in distilled water, while a slight decrease in material translucency was observed, except for Biomin C. However, significant differences in surface roughness and translucency were observed among some of the BAG-embedded specimens under both dry and wet conditions. The composition of elements declared by the glass manufacturer was confirmed by EDX analysis. Importantly, cytotoxicity analysis revealed that specimens containing BAGs, when released into the environment, did not adversely affect the growth of human gingival fibroblast cells after 48 h of exposure. This suggests that PMMA acrylics fabricated with BAGs have the potential to release ions into the environment and can be considered biocompatible materials. Further clinical trials are warranted to explore the practical applications of these materials as denture base materials. Full article

This article examines the effects of thermal aging and chemical disinfection on the microhardness and flexural strength of flexible resins. The influence of the resin type on the mechanical properties was also investigated. Two flexible resins, Deflex Classic SR and Deflex Supra SF, produced by the injection method, and a thermopolymerizable acrylic resin—ProBase Hot, produced by the flasking method, were subjected to 1000 cycles of thermal aging and three chemical disinfection protocols (n = 8), with daily immersion and during a recommended time, in Corega Whitening, Corega Oxygen Bio-Active, 2.5% sodium hypochlorite, and distilled water (control). Knoop microhardness and three-point flexural strength were evaluated. Data were analyzed using Wilcoxon, Mann–Whitney and Kruskal Wallis tests (α = 0.05). The results varied between 14.5 KHN and 80.1 MPa for ProBase Hot and 7.3 KHN for Deflex Classic SR and 52.5 MPa for Deflex Supra SF. Thermal aging reduced the microhardness of the flexible resins, but not their flexural strength. The microhardness of Deflex Classic SR was influenced by chemical disinfection with Corega Bio-active (p < 0.001). The flexural strength of Deflex Supra SF was influenced by chemical disinfection with Corega Whitening (p < 0.05). It can be concluded that chemical disinfection led to changes in the flexible resins and should be used with caution to maintain the mechanical properties of the resins. Flexible resins showed reduced resistance to physical and chemical environmental influences, which can affect their longevity. Full article

In this study, a bio-based acrylate resin derived from soybean oil was used in combination with a reactive diluent, isobornyl acrylate, to synthetize a composite scaffold reinforced with bioactive glass particles. The formulation contained acrylated epoxidized soybean oil (AESO), isobornyl acrylate (IBOA), a photo-initiator (Irgacure 819) and a bioactive glass particle. The resin showed high reactivity towards radical photopolymerisation, and the presence of the bioactive glass did not significantly affect the photocuring process. The 3D-printed samples showed different properties from the mould-polymerised samples. The glass transition temperature T_g showed an increase of 3D samples with increasing bioactive glass content, attributed to the layer-by-layer curing process that resulted in improved interaction between the bioactive glass and the polymer matrix. Scanning electron microscope analysis revealed an optimal distribution on bioactive glass within the samples. Compression tests indicated that the 3D-printed sample exhibited higher modulus compared to mould-synthetized samples, proving the enhanced mechanical behaviour of 3D-printed scaffolds. The cytocompatibility and biocompatibility of the samples were evaluated using human bone marrow mesenchymal stem cells (bMSCs). The metabolic activity and attachment of cells on the samples’ surfaces were analysed, and the results demonstrated higher metabolic activity and increased cell attachment on the surfaces containing higher bioactive glass content. The viability of the cells was further confirmed through live/dead staining and reseeding experiments. Overall, this study presents a novel approach for fabricating bioactive glass reinforced scaffolds using 3D printing technology, offering potential applications in tissue engineering. Full article

Background: The creation of the denture base material with bioactive properties that releases ions and produces hydroxyapatite. Methods: Acrylic resins were modified by the addition of 20% of four types of bioactive glasses by mixing with powders. Samples were subjected to flexural strength (1, 60 days), sorption and solubility (7 days), and ion release at pH 4 and pH 7 for 42 days. Hydroxyapatite layer formation was measured using infrared. Results: Biomin F glass-containing samples release fluoride ions for a period of 42 days (pH = 4; Ca = 0.62 ± 0.09; P = 30.47 ± 4.35; Si = 22.9 ± 3.44; F = 3.1 ± 0.47 [mg/L]). The Biomin C (contained in the acrylic resin releases (pH = 4; Ca = 41.23 ± 6.19; P = 26.43 ± 3.96; Si = 33.63 ± 5.04 [mg/L]) ions for the same period of time. All samples have a flexural strength greater than 65 MPa after 60 days. Conclusion: The addition of partially silanized bioactive glasses allows for obtaining a material that releases ions over a longer period of time. Clinical significance: This type of material could be used as a denture base material, helping to preserve oral health by preventing the demineralization of the residual dentition through the release of appropriate ions that serve as substrates for hydroxyapatite formation. Full article

Chokeberry (Aronia melanocarpa) pomace is a by-product from the juice industry very rich in anthocyanins and other bioactive components. Recovery and purification of anthocyanins from the pomace is a viable valorization strategy that can be implemented to produce high-value natural food colorants with antioxidant properties. In this study, chokeberry pomace was subjected to enzyme-assisted extraction using commercial pectinases. The extracts were further purified by adsorption–desorption using an acrylic resin and stabilized by co-pigmentation with ferulic acid. The anthocyanin concentration and antioxidant activity of the extracts were unaffected by the enzymatic treatment at the conditions tested. The total phenolic content of the extracts suffered minor variations depending on the enzyme formulation used, whereas the dissolved solid content increased in all cases. The adsorption–desorption strategy allowed a 96% recovery of the anthocyanins initially present in the extract, whereas the co-pigmentation treatment magnified the intensity of the color in terms of absorbance, and improved the stability during storage up to one month. Full article

Denture stomatitis is a multifactorial pathological condition of the oral mucosa that affects up to 72% of denture wearers. It is commonly seen on the palatal mucosa and characterized by erythema on the oral mucosa that are in contact with the denture surface. The aim of this study was to incorporate 2-methacryloyloxyethyl phosphorylcholine (MPC) and dimethylaminohexadecyl methacrylate (DMAHDM) into a high impact polymethylmethacrylate heat-cured denture base acrylic resin as a potential treatment for denture stomatitis. We used a comparative study design to examine the effect of incorporating MPC as a protein repellent agent and DMAHDM as an antifungal agent to prevent the adherence of Candida albicans to the denture base material. The dual incorporation of MPC and DMAHDM reduced C. albicans biofilm colony-forming unit by two orders of magnitude when compared to the control group devoid of the bioactive agents. Although the addition of MPC and DMAHDM alone or in combination significantly reduced the flexural strength of the material, they showed reduced roughness values when compared to control groups. This new denture acrylic resin provides the benefit of enhancing C. albicans biofilm elimination through dual mechanisms of action, which could potentially reduce the prevalence of denture stomatitis. Full article

Background: Oral hygiene is essential for maintaining residual dentition of partial denture wearers. The dental material should positively affect the oral environment. Fluoride-releasing dental materials help to inhibit microbial colonization and formation of plaque as well as to initiate the remineralization process in the early cavity area. Aim: To evaluate fluoride ion release and recharge capacity, sorption, and solubility of polymethyl methacrylate (PMMA) dental resin modified with bioactive glass addition. Materials and methods: Two bioactive glass materials (5 wt% Kavitan, 10 wt% Kavitan, and 10 wt% Fritex) and pure 10 wt% NaF were added to dental acrylic resin. After polymerization of the modified resins, the release levels of fluoride anions were measured based on color complex formation by using a spectrophotometer after 7, 14, 28, and 35 days of storage in distilled water at 37 °C. Subsequently, specimens were brushed with a fluoride-containing tooth paste on each side for 30 s, and the fluoride recharge and release potential was investigated after 1, 7, and 14 days. Sorption and solubility after 7 days of storage in distilled water was also investigated. Results: The acrylic resins with addition of 10% bioactive glass materials released fluoride ions for over 4 weeks (from 0.14 to 2.27 µg/cm²). The amount of fluoride ions released from the PMMA resin with addition of 10 wt% Fritex glass was higher than that from the resin with addition of 10 wt% Kavitan. The acrylic resin containing 10 wt% NaF released a high amount of ions over a period of 1 week (1.58 µg/cm²), but the amount of released ions decreased rapidly after 14 days of storage. For specimens containing 5 wt% Kavitan glass, the ion-releasing capacity also lasted only for 14 days. Fluoride ion rechargeable properties were observed for the PMMA resin modified with addition of 10 wt% Fritex glass. The ion release levels after recharge ranged from 0.32 to 0.48 µg/cm². Sorption values ranged from 10.23 μm/mm³ for unmodified PMMA resin to 12.11 μm/mm³ for specimens modified with 10 wt% Kavitan glass. No significant differences were found regarding solubility levels after 7 days. Conclusions: The addition of 10 wt% Fritex and 10 wt% Kavitan bioactive glass materials to heat-cured acrylic resin may improve its material properties, with bioactive fluoride ion release ability lasting for over 4 weeks. The resin modified with 10 wt% Fritex glass could absorb fluoride ions from the toothpaste solution and then effectively release them. Addition of fluoride releasing fillers have a small effect on sorption and solubility increase of the modified PMMA resin. Clinical significance: The addition of bioactive glass may be promising in the development of the novel bioactive heat-cured denture base resin. Full article

Biodentine^® is a bioactive dentin coating widely used for dental restoration; however, its adhesion to the substrate could limit its clinical success. The aim of this study was to evaluate the shear bond strength (SBS) between Biodentine^® and a composite resin, using different types of adhesive. In total, 120 acrylic blocks with a central hole were prepared. They were fully filled with Biodentine^®, and divided into two time groups: 12 min (n = 60) and 24 h (n = 60); each group was subdivided into four groups according to the adhesive: three-step etch and rinse (3-E&R) (n = 15), two-step etch and rinse (n = 15), and a universal adhesive subdivided into two groups, two-step etch and rinse (n = 15) and one-step self-etch adhesive system (n = 15). After adhesive application, the composite was applied and stored at 100% humidity, at 37 °C, for 24 h, before the SBS test. Data were analyzed with one-way ANOVA, Fisher post hoc test, and Kolmogorov–Smirnov test. The 12-min group showed statistically significant differences (p = 0.009), with the highest values of adhesion for 3-E&R. No statistically significant differences were observed for the 24-h group (p = 0.813) and between adhesive systems (p = 0.071) regardless of adhesion time. Higher adhesion values were found at 24 h. It is essential to consider the longest setting time for Biodentine^®. In terms of adhesive, 3-E&R had the highest adhesion values. Full article