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205
result(s) for
"radiopacity"
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Physicochemical properties of gutta-percha cones before and after a rapid disinfection protocol and its clinical relevance
by
Brito, José
,
Proença, Luís
,
Barroso, Helena
in
Antimicrobial activity
,
Chemical composition
,
Radiopacity
2026
This study aimed to evaluate the chemical composition, radiopacity, and antimicrobial activity of five standardized (#25) commercially available gutta-percha points (ProTaper Gold, Zarc, Cerkamed, Autofit, and Reciproc R25), before and after a rapid disinfection protocol. The cones were divided into three groups: untreated (control), treated with sodium hypochlorite, and treated with sodium hypochlorite followed by ethanol rinsing. Significant compositional differences, as assessed by a solvent extraction method, were observed among brands, with gutta-percha content ranging from 11.6 to 17.5%, wax and/or resin from 1.2 to 4%, and inorganic fraction between 74.0 and 83.0%, with ZnO as the predominant component. Radiopacity determined via digital radiography varied among brands and showed a stronger correlation with ZnO content than with BaSO₄, challenging the common assumption that barium is the principal radiopacifying agent; Zarc exhibited the highest radiopacity, whereas Cerkamed showed the lowest. None of the gutta-percha points exhibited antimicrobial activity against Enterococcus faecalis and Staphylococcus aureus under standard clinical conditions, underscoring the necessity of proper disinfection procedures in clinical practice. The disinfection protocols produced minor changes in the wax/resin content of Cerkamed, Reciproc, Autofit, and ProTaper, with the effect being more pronounced in the latter two. In contrast, the metal oxide composition analyzis with wavelength dispersive X-ray fluorescence (WDXRF), showed that only Zark exhibits slight variations in ZnO, BaSO₄, SiO₂, and CuO. However, these changes remain insufficient to be considered clinically relevant. Importantly, no effect on the radiographic integrity of the gutta-percha cones was observed, confirming the safety and adequacy of the NaOCl-based disinfection protocols for clinical purposes.
Journal Article
A Systematic Review on 3D-Printed Imaging and Dosimetry Phantoms in Radiation Therapy
2019
Introduction:
Additive manufacturing or 3-dimensional printing has become a widespread technology with many applications in medicine. We have conducted a systematic review of its application in radiation oncology with a particular emphasis on the creation of phantoms for image quality assessment and radiation dosimetry. Traditionally used phantoms for quality assurance in radiotherapy are often constraint by simplified geometry and homogenous nature to perform imaging analysis or pretreatment dosimetric verification. Such phantoms are limited due to their ability in only representing the average human body, not only in proportion and radiation properties but also do not accommodate pathological features. These limiting factors restrict the patient-specific quality assurance process to verify image-guided positioning accuracy and/or dose accuracy in “water-like” condition.
Methods and Results:
English speaking manuscripts published since 2008 were searched in 5 databases (Google Scholar, Scopus, PubMed, IEEE Xplore, and Web of Science). A significant increase in publications over the 10 years was observed with imaging and dosimetry phantoms about the same total number (52 vs 50). Key features of additive manufacturing are the customization with creation of realistic pathology as well as the ability to vary density and as such contrast. Commonly used printing materials, such as polylactic acid, acrylonitrile butadiene styrene, high-impact polystyrene and many more, are utilized to achieve a wide range of achievable X-ray attenuation values from −1000 HU to 500 HU and higher. Not surprisingly, multimaterial printing using the polymer jetting technology is emerging as an important printing process with its ability to create heterogeneous phantoms for dosimetry in radiotherapy.
Conclusion:
Given the flexibility and increasing availability and low cost of additive manufacturing, it can be expected that its applications for radiation medicine will continue to increase.
Journal Article
Distrontium Cerate as a Radiopaque Component of Hydraulic Endodontic Cement
by
Wada, Takahiro
,
Adel, Sherif
,
Kurabayashi, Tohru
in
Aluminum
,
Cement hydration
,
Cerium oxides
2021
This study aimed to synthesize distrontium cerate (2SrO·CeO2: S2Ce) and evaluate its properties as an alternative component of the endodontic cement. S2Ce cement was prepared through calcination of strontium hydroxide and cerium carbonate. Subsequently, the crystal phase was confirmed using X-ray diffraction. S2Ce cement exhibited a rapid setting time (121 min) and achieved a high compressive strength (72.1 MPa) at 1 d after mixing, comparable to the compressive strength of a commercial mineral trioxide aggregate (MTA) cement (ProRoot MTA) after 28 d post mixing. However, the compressive strength decreased after 28 d of storage when the W/P ratio was 0.30–0.40 (p < 0.05). Ion dissolution test of the S2Ce cement showed that strontium ions were released after immersion in water (5.27 mg/mL after 1 d), whereas cerium dissolution was not detected. S2Ce exhibited approximately three times higher radiopacity (9.0 mm aluminum thickness equivalent) compared to the commercial MTA (p < 0.05). These findings suggest that S2Ce is a possible component for hydraulic endodontic cement that demonstrates a rapid setting and high radiopacity.
Journal Article
Physicochemical characteristics and discolouration potentials of Pulpine mineral® and Pulpine NE
by
Abu-Seida, Ashraf
,
Fakhr Eldeen, Mai
,
Hashem, Ahmed
in
Crown discoloration
,
Pulpine mineral
,
Pulpine NE
2024
ABSTRACT Aim: To compare the physicochemical properties (solubility, pH, radiopacity and crown discoloration) of Pulpine mineral (PMIN) and Pulpine NE (PNE) with the conventional material, mineral trioxide aggregate (MTA). Methodology: Specimens of the tested materials were prepared according to the manufacturer’s instructions using split Teflon ring molds. Solubility was evaluated by the percentage of material mass loss over 24 h and one week. The alkalinity was measured after each evaluation period using a pH meter. Other specimens were digitally radiographed on a size 2 sensor plate along with an aluminum step wedge to analyze the radiopacity by the Image J software. Finally, crown discoloration was assessed after applying the tested materials in the pulp chamber of sound human premolars using spectrophotometer. All data were statistically analyzed. Results: Compared to MTA, both materials had significantly higher solubility and lower radiopacity (P<0.05). The alkalinity of PMIN was higher than that of MTA and PNE. Unlike PMIN, PNE and MTA caused crown discoloration. Conclusions: PMIN exhibits promising results related to high alkalinity and adequate color stability but it needs modifications for radiopacity and solubility.
Journal Article
3D printed composite materials for craniofacial implants: current concepts, challenges and future directions
by
Manzoor, Faisal
,
Jindal, Swati
,
Mancuso, Elena
in
3-D printers
,
Additive manufacturing
,
Biomedical materials
2021
Millions of craniofacial surgeries are performed annually worldwide for craniofacial bones’ replacement and augmentation. This represents a significant economic burden as well as aesthetic expectations. Autografts and allografts are the first choice for treatment of craniofacial defects; however, their limited availability and difficulty to shape have led to investigation for alternative strategies. Biomaterial-based approaches have been used for implantation as they have ample supply but their processing through conventional technologies present several drawbacks; the major one relates to the poor versatility towards the production of patient-specific implants. Additive manufacturing has gained considerable attention during the last decade, as it allows the manufacturing of implants according to patient need. Biomaterial implants can be additively manufactured but have one or more limitations of stress shielding, radiopacity, high strength to weight ratio and limited bone integration. Over the last few decades, composites are investigated to surmount the limitations with traditional implants and also improve their bone integration. This review provides an overview of the most recent polymeric composite-based biomaterials that have been used in combination with 3D printing technology for the development of patient-specific craniofacial implants. Starting with the conventional treatments, biomaterials available for the craniofacial implants, the additive manufacturing rationale are discussed. Also, the main challenges still associated with 3D printing of polymer-based composites are critically reviewed and the future perspective presented.
Journal Article
Overviews on the Progress of Flowable Dental Polymeric Composites: Their Composition, Polymerization Process, Flowability and Radiopacity Aspects
2022
A review article has been conducted including the main research results and comments referring to flowable dental polymeric materials. To begin with, the synthesis and composition of this category of composites is discussed, revealing the major components of the commercial products in terms of chemistry and proportion. Later, the polymerization characteristics are unfolded regarding the reaction time and rate, volumetric shrinkage and depth of cure for both photocurable and self-curable composites. To continue, some perspectives of the pre-treatment or accompanying processes that a clinician may follow to enhance the materials’ performance are described. Fluidity is certainly associated with the progress of polymerization and the in-depth conversion of monomers to a polymeric network. Last, the aspects of radiopacity and translucency are commented on, showing that all flowable polymeric composites satisfy the radiography rule, while the masking ability depends on the fillers’ properties and specimen thickness. The reviewing article is addressed to all field scientists and practitioners dealing with flowable dental composites studies or applications.
Journal Article
A Short Review on Biomedical Applications of Nanostructured Bismuth Oxide and Related Nanomaterials
by
Tagliaferro, Alberto
,
Bartoli, Mattia
,
Jagdale, Pravin
in
Antimicrobial agents
,
Apoptosis
,
Atoms & subatomic particles
2020
In this review, we reported the main achievements reached by using bismuth oxides and related materials for biological applications. We overviewed the complex chemical behavior of bismuth during the transformation of its compounds to oxide and bismuth oxide phase transitions. Afterward, we summarized the more relevant studies regrouped into three categories based on the use of bismuth species: (i) active drugs, (ii) diagnostic and (iii) theragnostic. We hope to provide a complete overview of the great potential of bismuth oxides in biological environments.
Journal Article
Correlation between Dental Composite Filler Percentage and Strength, Modulus, Shrinkage Stress, Translucency, Depth of Cure and Radiopacity
by
Nizami, Bushra
,
Lawson, Nathaniel C.
,
Gummadi, Snigdha
in
Bend strength
,
Bulk modulus
,
Composite materials
2024
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.
Journal Article
Doped Calcium Silicate Ceramics: A New Class of Candidates for Synthetic Bone Substitutes
2017
Doped calcium silicate ceramics (DCSCs) have recently gained immense interest as a new class of candidates for the treatment of bone defects. Although calcium phosphates and bioactive glasses have remained the mainstream of ceramic bone substitutes, their clinical use is limited by suboptimal mechanical properties. DCSCs are a class of calcium silicate ceramics which are developed through the ionic substitution of calcium ions, the incorporation of metal oxides into the base binary xCaO–ySiO2 system, or a combination of both. Due to their unique compositions and ability to release bioactive ions, DCSCs exhibit enhanced mechanical and biological properties. Such characteristics offer significant advantages over existing ceramic bone substitutes, and underline the future potential of adopting DCSCs for clinical use in bone reconstruction to produce improved outcomes. This review will discuss the effects of different dopant elements and oxides on the characteristics of DCSCs for applications in bone repair, including mechanical properties, degradation and ion release characteristics, radiopacity, and biological activity (in vitro and in vivo). Recent advances in the development of DCSCs for broader clinical applications will also be discussed, including DCSC composites, coated DCSC scaffolds and DCSC-coated metal implants.
Journal Article
Physicochemical characterization of a recently developed resin-based calcium silicate cement compared to established pulp capping materials
2026
This study aimed to compare the physical and chemical properties of TheraBase, a newly introduced resin-based calcium silicate cement, with TheraCal LC, Biodentine, and Bio MTA+ under in vitro conditions. Disc-shaped specimens were prepared from each material. Compressive strength was tested using a universal testing machine, radiopacity was assessed through digital radiographic analysis, and water sorption and solubility were determined based on weight changes after immersion. pH and calcium ion release were measured at multiple time points. Data were analyzed using ANOVA and post hoc tests (
p
< 0.05). TheraBase exhibited the highest compressive strength, whereas Bio MTA+ showed the lowest values. Biodentine showed the highest solubility, whereas TheraCal LC had the lowest. TheraBase presented the lowest values for water sorption, pH, and calcium ion release (
p
< 0.05). TheraBase demonstrated favorable properties, including high compressive strength, low solubility, and adequate radiopacity, suggesting its potential for clinical use in pulp capping. However, its low calcium ion release may limit its regenerative potential.
Journal Article