Search Results (97)

Polyetheretherketone (PEEK) is a high-performance, biocompatible polymer with remarkable mechanical properties, making it a promising candidate for medical implants. However, its intrinsic radiolucency poses a challenge for post-operative imaging. This study investigates the photon shielding capabilities and X-ray imaging qualities of pure PEEK and its composites with barium sulfate (BaSO₄), tantalum (Ta), bismuth oxide (Bi₂O₃), and hydroxyapatite (HA). The Monte Carlo-based Geant4 toolkit and the EpiXS application were used to evaluate key photon interaction parameters, including mass attenuation coefficients, effective atomic number (Z_eff), and effective electron density (N_eff), as well as the imaging performance metrics such as energy deposition and signal-to-noise ratio (SNR). Results indicate that high atomic number composites significantly enhance PEEK’s photon attenuation and imaging contrast. PEEK-Bi₂O₃ exhibited the highest attenuation coefficients and energy deposition, making it the most effective X-ray shielding material. PEEK-Ta provided a balanced performance with enhanced shielding and lower secondary radiation effects, making it suitable for applications requiring both radiopacity and imaging stability. PEEK-BaSO₄ moderately improved attenuation while maintaining a lower density, offering a trade-off between radiopacity and mechanical properties. Conversely, PEEK-HA demonstrated minimal enhancement in photon attenuation, limiting its effectiveness for radiographic applications. The findings suggest that incorporating high atomic number elements into PEEK significantly enhances its suitability for radiopaque medical implants, allowing for improved post-operative monitoring. Full article

The calcium silicate-based sealers currently available on the market have different compositions and formulations, which is why their physical and chemical properties may vary. (1) The aim of the study was to measure the physico-chemical properties of calcium silicate-based sealers and their push-out bond strength to root dentine, comparing two push-out testing protocols. (2) Standardized specimens of EndoSequence BC, BioRoot RCS, MTA Fillapex, and AH Plus (control) were subjected to pH measurements over 28 days. Radiopacity was measured using a CCD sensor, and flexural strength was assessed using a three-point bending setup. Push-out bond strength was measured in coronal, middle, and apical sections of 40 single-root teeth (conventional method), and cylindrical cavities were prepared for all sealers on the same root dentine disks in 11 third molars (disk method). (3) EndoSequence BC exhibited a higher pH than MTA Fillapex and the highest radiopacity (p < 0.05). The highest flexural and push-out bond strengths were found for AH Plus. The push-out bond strength of EndoSequence BC and BioRoot RCS was higher than MTA Fillapex (p < 0.05). The conventional and disk methods exhibited similar push-out bond strength results, but the data were more homogeneously distributed in the disk method. (4) All calcium silicate-based sealers exhibited a higher pH than AH Plus. MTA Fillapex did not meet the ISO standard. Calcium silicate-based sealers showed weaker performance in terms of physical properties compared to AH Plus. Full article

Resorbable medical devices provide temporary functionality before degrading into safe byproducts. One application is absorbable inferior vena cava filters (IVCFs), which prevent pulmonary embolism in high-risk patients with contraindications to anticoagulants. However, current absorbable IVCFs are limited by radiolucency and local clot formation risks. This study aimed to develop radiopaque, drug-loaded resorbable IVCFs with enhanced imaging and therapeutic capabilities. Poly-p-dioxanone (PPDO) sutures were infused with gadolinium nanoparticles (GdNPs) and dipyridamole (DPA), an anti-thrombotic agent. GdNPs were synthesized with an average diameter of 35.76 ± 3.71 nm. Gd content was 371 ± 1.6 mg/g (PPDO-Gd) and 280 ± 0.3 mg/g (PPDO-Gd + DPA), while the DPA content was 18.20 ± 5.38 mg/g (PPDO-DPA) and 12.91 ± 0.83 mg/g (PPDO-Gd + DPA). Suture thickness (0.39–0.49 cm, p = 0.0143) and melting temperature (103.61–105.90, p = 0.0002) statistically differed among the different groups, while load-at-break did not (4.39–5.38, p = 0.2367). Although suture thickness and melting temperatures differed significantly, load-at-break was preserved and did not alter the mechanical and degradation properties of the various IVCFs. Micro-computed tomography revealed enhanced radiopacity for Gd-containing IVCFs (2713 ± 105 HU for PPDO-Gd, 1516 ± 281 HU for PPDO-Gd + DPA). Radiopacity decreased gradually over 10–12 weeks. Clot-trapping efficacy was maintained, and no hemolysis or cellular toxicity was observed. In conclusion, the GdNP- and DPA-infused PPDO IVCFs demonstrated improved radiopacity, anti-thrombotic potential, and compatibility with routine imaging, without compromising mechanical strength or safety. Full article

Two 3D-printed crown materials (Crown and Ceramic Crown) were examined to determine the best surface treatment and primers for bonding. Discs of the two materials were printed and mounted with their “intaglio” surfaces untouched. Half the specimens from each group were sandblasted with 50 µm alumina. Then, specimens were divided into four groups (n = 10): Gr1—no further treatment; Gr2—one coat of silane; Gr3—one coat of universal adhesive; Gr4—one coat of silane, then one coat of universal adhesive. Bond strength specimens were prepared with an Ultradent shear bond strength apparatus using Filtek Supreme composite. Specimens were stored for 8 weeks in 37 °C water. The specimens were debonded with a circular notched-edge blade applied at 1 mm/min, and the shear bond strength was calculated. The data were compared with a two-way ANOVA (factors: surface treatment and primer) and a Tukey post hoc analysis for both materials independently, with p < 0.01 considered meaningful. The filler content (burned ash) and resin content (FTIR) of the materials were determined. For both materials, factors surface treatment and primer were significant (p < 0.01), but their interaction was not (p = 0.43 for Crown and p = 0.34 for Ceramic Crown). Alumina air particle abrasion improved the bond strength for both materials. The Tukey post hoc analysis grouped primer treatments into the same statistically different groups for both materials: Gr1 and Gr2 < Gr3 and Gr4. The filler percentage of Crown was 32.7% and Ceramic Crown was 48.2%. Resin content was similar for both materials. The most effective method to bond to 3D-printed crowns (regardless of filler percentage) was to sandblast with 50 µm alumina and apply a layer of adhesive (with or without previous application of silane). Full article

A novel water-soluble root canal filling material based on sodium iodide (NaI) has been developed to overcome the limitations of existing iodine-based formulations. However, the biological stability of this approach in animal studies remains unverified. This study evaluated the biocompatibility of NaI compared to commercial root canal filling materials (Calcipex II and Vitapex^®) in pulpectomized canine teeth to assess its clinical applicability. Following a four-week observation period, none of the experimental groups exhibited tooth mobility or fistula formation. Radiographic and micro-CT analyses revealed no radiolucency in periapical lesions. Histopathologic evaluation demonstrated the absence of inflammatory responses in periapical regions across all material groups, with histological inflammation scoring 0. High-magnification histological examination of periapical areas showed well-preserved periodontal ligament tissue in all groups. Despite certain limitations of NaI-based fillings in the pulp cavity, including loss of radiopacity and tooth discoloration, NaI demonstrates potential as a safe and effective alternative for pulp filling material, particularly due to its minimal risk of root resorption and inflammatory response. Full article

Objective: Image-guided diagnosis and treatment of lung lesions is an active area of research. With the growing number of solutions proposed, there is also a growing need to establish a standard for the evaluation of these solutions. Thus, realistic phantom and preclinical environments must be established. Realistic study environments must include implanted lung nodules that are morphologically similar to real lung lesions under X-ray imaging. Methods: Various materials were injected into a phantom swine lung to evaluate the similarity to real lung lesions in size, location, density, and grayscale intensities in X-ray imaging. A combination of $n$-butyl cyanoacrylate (n-BCA) and ethiodized oil displayed radiopacity that was most similar to real lung lesions, and various injection techniques were evaluated to ensure easy implantation and to generate features mimicking malignant lesions. Results: The techniques used generated implanted nodules with properties mimicking solid nodules with features including pleural extensions and spiculations, which are typically present in malignant lesions. Using only n-BCA, implanted nodules mimicking ground glass opacity were also generated. These results are condensed into a set of recommendations that prescribe the materials and techniques that should be used to reproduce these nodules. Conclusions: Generated recommendations on the use of n-BCA and ethiodized oil can help establish a standard for the evaluation of new image-guided solutions and refinement of algorithms in phantom and animal studies with realistic nodules. Full article

Medical tubing, particularly cardiovascular tubing, is a critical area of research where continuous improvements are necessary to advance medical devices and improve patient care. While polymers are fundamental for these applications, on their own they present several limitations such as insufficient X-ray contrasting capabilities. As such, polymer composites utilizing radiopaque fillers are a necessity for this application. For medical tubing in vivo, radiopacity is a crucial parameter that virgin polymers alone fall short in achieving due to limited X-ray absorption. To address this shortcoming, inorganic radiopaque fillers such as barium sulphate (BaSO₄) and bismuth oxychloride (BiOCl) are incorporated into polymer matrices to increase the X-ray contrast of the manufactured tubing. It is also known, however, that the incorporation of these fillers can affect the mechanical, physical, and thermal properties of the finished product. This research evaluated the impact of incorporating the two aforementioned fillers into Pebax^® 6333 SA01 MED at three different loading levels (10, 20, and 30 wt.%) on the physical, thermal, and mechanical properties of the composite. Composites were prepared by twin screw extrusion and injection molding followed by characterization of the mechanical (tensile, impact, and flexural), thermal (DSC), rheological (MFI), and physical (density and ash content) properties. The performed analysis shows that BiOCl enhanced the aesthetic properties, increased stiffness, and maintained flexibility while having minimal impact on the tensile and impact properties. When comparing BiOCl to BaSO₄-filled composites, it was clear that depending on the application of the polymer composite, BiOCl may provide more desirable properties. The study highlights the importance of optimizing filler concentration and processing conditions to achieve desired composite properties for specific medical applications. Full article

Radiopaque polyurethanes are extensively used in biomedical fields owing to their favorable balance of properties. This research aims to investigate the influence of particle concentration on various properties, including rheological, radiopacity, structural, thermal, and mechanical attributes, with a thorough analysis. The findings are benchmarked against a commercial product (PL 8500 A) that contains 10% weight barium sulfate. Two more thermoplastic polyurethanes (TPU) were formulated with two different concentrations of barium sulfate (10 wt.% and 20 wt.%) and compared to the commercially available product. FTIR demonstrated similar absorption bands among all samples, indicating that the fabrication method did not impact the TPU matrix. DSC indicated a predominantly amorphous structure for PL 8500 A compared to the other samples, while the kinetic degradation was more influenced by the higher barium sulfate content. The rheological analysis showed a decrease in the complex viscosity and storage modulus with the radiopacifier and an increase in the radiopacity, as demonstrated by the X-radiography. X-ray microtomography showed a more spherical particle format with a heterogeneous particle structure for PL 8500 A compared to the other polyurethanes. These findings enhance the comprehension of the structure–property relationships inherent in these materials and facilitate the development of customized materials for targeted applications. Full article

Background/Objectives: The therapeutic approach to bone mass loss and bone’s limited self-regeneration is a major focus of research, emphasizing new biomaterials and cell therapy. Tissue bioengineering emerges as a potential alternative to conventional treatments. In this study, an experimental model of a critical bone lesion in rats was used to investigate bone regeneration by treating the defect with biomaterials Evolution^® and Gen-Os^® (OsteoBiol^®, Turín, Italy), with or without mesenchymal stromal cells from dental pulp (DP-MSCs). Methods: Forty-six adult male Wistar rats were subjected to a 5-mm critical bone defect in the right mandible, which does not regenerate without intervention. The rats were randomly assigned to a Simulated Group, Control Group, or two Study Groups (using Evolution^®, Gen-Os^®, and DP-MSCs). The specimens were euthanized at three or six months, and radiological, histological, and ELISA tests were conducted to assess bone regeneration. Results: The radiological results showed that the DP-MSC group achieved uniform radiopacity and continuity in the bone edge, with near-complete structural defect restitution. Histologically, full bone regeneration was observed, with well-organized, vascularized lamellar bone and no lesion edges. These findings were supported by increases in endoglin, transforming growth factor-beta 1 (TGF-β1), protocollagen, parathormone, and calcitonin, indicating a conducive environment for bone regeneration. Conclusions: The use of DP-MSCs combined with biomaterials with appropriate three-dimensional matrices is a promising therapeutic option for further exploration. Full article

Polyurethanes are used in a wide range of biomedical applications due to their variety of physical–chemical, mechanical, and structural properties, and biotic and abiotic degradation. They are widely used in bio-imaging procedures when metallic-based filler particles are incorporated, making the final product radiopaque. It would be advantageous, however, if polyurethanes with intrinsic radiopacity could be produced in their synthesis, avoiding a series of disadvantages in the processing and final product and also presenting potential antimicrobial activities. This review’s objective was to study the radiopacifying characteristics of nanoparticles, the physical principles of radiopacity, and the variety of medical applications of polyurethanes with nanoparticles. It was found in this study that the synthetization of radiopaque polyurethanes is not only possible but the efficiency of synthetization was improved when using atoms with high electron density as part of the backbone or when grafted, making them great multipurpose materials. Full article

Mandibular reconstruction for large bone defects is performed with consideration of patients’ specific morphology and sufficient strength. Metal additive manufacturing techniques have been used to develop biomaterials for mandibular reconstruction. Titanium artificial mandibles with a lattice structure have been proposed, and the optimal conditions for their strength to withstand mechanical stress around the mandible have been reported. This study investigated the biocompatibility of a titanium artificial bone with a lattice structure fabricated under optimal conditions. The samples were fabricated using metal additive manufacturing. Body diagonals with nodes (BDN) were selected as suitable lattice structures. Dode medium (DM) was selected for comparison. The samples were implanted into rabbit tibial defects and resected with the surrounding bone at two and four weeks. Specimens were evaluated radiographically, histologically, and histomorphometrically. Radiopacity in each lattice structure was observed at two and four weeks. Histological evaluation showed trabecular bone-like tissue inside the BDN compared to the DM at four weeks. No significant differences were noted in the bone volume inside the structures. This study demonstrated the in vivo compatibility of artificial metallic bones with a BDN structure under mechanical stress conditions. Full article

Filler content in dental composites is credited for affecting its physical and mechanical properties. This study evaluated the correlation between the filler percentage and strength, modulus, shrinkage stress, depth of cure, translucency and radiopacity of commercially available high- and low-viscosity dental composites. Filler weight percentage (wt%) was determined through the burned ash technique (800 °C for 15 min). Three-point bend flexural strength and modulus were measured according to ISO 4049 with 2 mm × 2 mm × 25 mm bars. Shrinkage stress was evaluated using a universal testing machine in which composite was polymerized through two transparent acrylic rods 2 mm apart. Shrinkage was measured from the maximum force following 500 s. The translucency parameter (TP) was measured as the difference in color (ΔE00) of 1 mm thick specimens against white and black tiles. The depth of cure was measured according to ISO 4049 in a cylindrical metal mold (4 mm diameter) with a 10 s cure. Radiopacity was measured by taking a digital X-ray (70 kVp for 0.32 s at 400 mm distance) of 1 mm thick specimens and comparing the radiopacity to an aluminum step wedge using image analysis software. The correlation between the filler wt% and properties was measured by Pearson’s correlation coefficient using SPSS. There was a positive linear correlation between the filler wt% and modulus (r = 0.78, p < 0.01), flexural strength (r = 0.46, p < 0.01) and radiopacity (r = 0.36, p < 0.01) and negative correlation with translucency (r = −0.29, p < 0.01). Filler wt% best predicts the modulus and strength and, to a lesser extent, the radiopacity and translucency. All but two of the high- and low-viscosity composites from the same manufacturer had statistically equivalent strengths as each other; however, the high-viscosity materials almost always had a statistically higher modulus. For two of the flowable composites measured from the same manufacturer (3M and Dentsply), there was a lower shrinkage stress in the bulk-fill version of the material but not for the other two manufacturers (Ivoclar and Tokuyama). All flowable bulk-fill composites achieved a deeper depth of cure than the flowable composite from the same manufacturer other than Omnichroma Flow Bulk. Full article

In the present work, iron–sillenite (Bi₂₅FeO₄₀) was synthesized using a simple solid-state reaction method and characterized. The effects of the synthesis conditions on the phase purity of Bi₂O₃/Fe₃O₄, morphological features, and possible application as an XRD/MRI dual-contrast agent were investigated. For the synthesis, the stoichiometric amounts of Bi₂O₃ and Fe₃O₄ were mixed and subsequently milled in a planetary ball mill for 10 min with a speed of 300 rpm. The milled mixture was calcined at various temperatures (550 $°$C, 700 $°$C, 750 $°$C, 800 $°$C, and 850 $°$C) for 1 h in air at a heating rate of 5 °C/min. For phase identification, powder X-ray diffraction (XRD) analysis was performed and infrared (FTIR) spectra were recorded. The surface morphology of synthesized samples was studied by field-emission scanning electron microscopy (FE-SEM). For the radiopacity measurements, iron–sillenite specimens were synthesized at different temperatures and mixed with different amounts of BaSO₄ and Laponite solution. It was demonstrated that iron–sillenite Bi₂₅FeO₄₀ possessed sufficient radiopacity and could be a potential candidate to meet the requirements of its application as an XRD/MRI dual-contrast agent. Full article

Premature loss of root canal-treated primary teeth has long been a concern in dentistry. To address this, researchers developed a sodium iodide-based root canal-filling material as an alternative to traditional iodoform-based materials. The goal of this study was to improve the physicochemical properties of the sodium iodide-based material to meet clinical use standards. To resolve high solubility issues in the initial formulation, researchers adjusted component ratios and added new ingredients, resulting in a new paste called L5. This study compared L5 with L0 (identical composition minus lanolin) and Vitapex as controls, conducting physicochemical and antibacterial tests. Results showed that L5 met all ISO 6876 standards, demonstrated easier injection and irrigation properties than Vitapex, and exhibited comparable antibacterial efficacy to Vitapex, which is currently used clinically. The researchers conclude that if biological stability is further verified, L5 could potentially be presented as a new option for root canal-filling materials in primary teeth. Full article

Divalent cations have captured the interest of researchers in biomedical and dental fields due to their beneficial effects on bone formation. These metallic elements are similar to trace elements found in human bone. Strontium is a divalent cation commonly found in various biomaterials. Since strontium has a radius similar to calcium, it has been used to replace calcium in many calcium-containing biomaterials. Strontium has the ability to inhibit bone resorption and increase bone deposition, making it useful in the treatment of osteoporosis. Strontium has also been used as a radiopacifier in dentistry and has been incorporated into a variety of dental materials to improve their radiopacity. Furthermore, strontium has been shown to improve the antimicrobial and mechanical properties of dental materials, promote enamel remineralization, alleviate dentin hypersensitivity, and enhance dentin regeneration. The objective of this review is to provide a comprehensive review of the applications of strontium in dentistry. Full article