Disk Shape Research Articles

Streptococcus-mutans and Porphyromonas-gingivalis adhesion to glazed/polished surfaces of CAD/CAM restorations

PurposeDental restorations fabricated using CAD/CAM require modification/adjustment before cementation. Streptococcus mutans (S.mutans) and Porphyromonas gingivalis (P.gingivalis) are prevalent bacterial species that may adhere to these materials and can cause caries, gingivitis/periodontitis. The purpose of this in vitro study was to evaluate the bacterial adherence of S.mutans and P.gingivalis to five different kinds of modern CAD/CAM restorative materials with different compositions following chairside finishing/polishing and glazing. Materials and methodsSpecimens (N = 75) from five test materials (n = 15 each) “Tetric-CAD®; IPS-e.max-CAD®; IPS-e.max-ZirCAD®; CELTRA-Duo® and Vita-Enamic®” were prepared in disc shape (10 × 3 mm) using CAD/CAM. The specimens underwent glazing and finishing/polishing using established procedures. The surface roughness was measured in micrometers (μm) using a profilometer. Bacterial adherence to test materials' glazed and finished/polished surfaces was tested using bacterial culture growth over the test materials. Data obtained was tabulated and statistical analysis performed using Kruskal Wallis test, post-hoc Conover test, Mann-Whitney U test and Tukey post hoc test. ResultsWith the exception of IPS-e.max-ZirCAD®, which showed the contrary, the adherence of S.mutans & P.gingivalis was less on glazed surfaces compared to finished/polished surfaces for four test materials: “Tetric-CAD®, IPS-e.max-CAD®, CELTRA-Duo®, and Vita-Enamic®”. On the glazed surfaces, the adhesiveness of S.mutans and P.gingivalis was not significant (p = 0.099; p = 0.660); however, on the finished/polished surfaces, it was significant (p = 0.002; p = 0.004). With the exception of ‘IPS-e.max-ZirCAD®’, which showed the reverse behavior, the adhesion of S.mutans & P.gingivalis to finished/polished surfaces was greater for each of the four ceramics under investigation “Tetric-CAD®, IPS-e.max-CAD®, CELTRA-Duo®, and Vita-Enamic®”. ConclusionGlazed surfaces for majority of test materials demonstrated decreased adhesion from S.mutans &P.gingivalis, hence prior to final placement of restoration, it is advised to adhere to the minimal glazing criteria. Regardless of the chemical composition of the materials, the surface texture of the tested materials significantly influenced bacterial adhesion.

Is It Possible for Single-shade Composites to Mimic the Color, Lightness, Chroma, and Hue of Other Single-shade Composites? An In Vitro Study.

This study aimed to assess color matching post-repair using the same or different single-shade composites of three distinct composite resin materials (Omnichroma-OM, ZenChroma-ZC, and Charisma Topaz One-CTO) following aging in coffee solution and distilled water. Evaluation focused on color change parameters (∆E00, ∆L00, ∆C00, and ∆H00). Specimens were prepared in disk shape with a diameter of 8 mm and a height of 2 mm (n=180). Half of each composite group was immersed in distilled water, while the other half was immersed in coffee solution for 12 days each (n=90). After aging, cylindrical cavities with a diameter of 4 mm and a depth of 1 mm were prepared at the center of the specimens. The cavities were repaired with both themselves and other composite resins (n=10). Color measurements of the specimens were performed using VITA Easyshade 5 (VITA Zahnfabrik, Bad Säckingen, Germany) at the following time points: baseline (T0), after aging (12 days) (T1), immediately after repair (T2), one day after repair (T3), one week after repair (T4), and one month after repair (T5). Statistically significant differences were found in the mean ΔE00 measurements among the study groups at all time points for each of the three composite resins (p<0.05). Similarly, statistically significant differences were found in the mean ΔE00 measurements over time for each of the three composite resins in each study group (p<0.05). The baseline measurements of materials repaired with themselves in the distilled water groups and the final measurements of materials repaired with themselves in the coffee groups were found to be within acceptable ∆E00limits. At the end of the study, only CTO repaired with OM showed acceptable color matching with different composites in both coffee and distilled water groups. Acceptable color matching was achieved when using the same material for repair in specimens aged in distilled water and coffee. However, variations in matching were observed when different materials were used for repair, indicating the need for ongoing monitoring. Contributions of ΔL00, ΔC00, and ΔH00 values to color differences vary depending on the resins and repair process and change over time.

Observation of dynamic position and morphological changes of temporomandibular joint discs under Angle's classification

Objective: To observe the dynamic changes of the temporomandibular joint (TMJ) disc in joint movement under different Angle's classification, providing reference for understanding joint functional movement and providing a basis for more accurate clinical imaging diagnosis. Methods: A total of 30 patients (13 males and 17 females) with temporomandibular disorders who were admitted to Beijing Friendship Hospital, Capital Medical University and General Hospital of the People's Liberation Army from January 2022 to April 2024 were enrolled. Thirty adults (13 males and 17 females) with different Angle's classification, with an average age of (34.4±8.5) years, were subjected to dynamic imaging of their TMJ from the closed position to the maximum opening position, and then to the closed position using MRI. The position and morphological changes of the articular discs were observed. Results: The results showed that volunteers with no displacement of the articular disc in class Ⅰ, Ⅱ, and Ⅲ relationships had different shapes of the articular disc during open and closed mouth movements. However, in the maximum opening position, the articular disc were all located directly below the maxillary nodules, and their shape is double concave. In terms of irreversible anterior displacement of the articular disc, in class Ⅰ Angle, the posterior zone of the disc contacts the anterior inclined plane of condyle from the maximum opening position back to the front of the closing position. In class Ⅱ, the posterior zone of the disc contacts the anterior inclined plane of condyle from the beginning of opening position to maximum opening position. In class Ⅲ, the posterior zone of the disc is always in contact with the anterior inclined plane of condyle throughout the entire movement process. And among them, the articular disc presents a forward displacement state at the closing position, its morphology undergoes folding phenomenon. When the openness is 2.5 cm, the articular disc moves up to a certain extent, and is closer to the anterior inclined plane of condyle, and its shape is also partially changed. When the openness is 4.3 cm, the shape of the articular disc, located between the anterior inclined plane of the joint node and the posterior inclined plane of the condyle, is typical double concave, which is sufficient to show that the articular disc is reversible when maximum opening position is reached. In terms of reversible anterior disc displacement, in class Ⅰ Angle, the posterior zone of the disc contact with the anterior inclined plane of condyle at the beginning of the opening position and the end of the closing position. In classⅡ Angle, the posterior zone of the articular disc is not in contact with the anterior inclined plane of condyle. In class Ⅲ Angle, the posterior zone of the articular disc contact with the anterior inclined plane of condyle at the end of the closing position. Conclusions: Multi level dynamic MR imaging data of the temporomandibular joint can dynamically observe the movement of the temporomandibular joint, intuitively and accurately display the position and shape of the articular disc during movement, and can serve as a useful supplement to static conventional MR imaging of the TMJ. The patient's TMJ needs to reach the maximum opening position in order to determine whether the joint disc displacement can be reversible or not.

Novel single-cell measurements suggest irreversibly sickled cells are neither dense nor dehydrated

In sickle cell anemia, deoxygenation causes erythrocytes to distort, while reoxygenation permits them to recover a normal biconcave disk shape. Irreversibly sickled cells (ISCs) remain distorted when reoxygenated and have been thought to have among the highest intracellular hemoglobin concentrations of the sickle red cell population and therefore the greatest vulnerability to vasoocclusion. Using a new optical method, which we describe, we have made precise measurements of the intracellular hemoglobin concentration, and intracellular O2 saturation, of ISCs, as well as oxygenated sickle cells with a normal biconcave disc shape, and cells with shapes distorted by the sickle fibers they contain. This method also provides good estimates of cell volumes, and hemoglobin per red cell. The concentration distribution of the ISCs is found to be similar to normal, discoid cells. Average ISC volumes exceed their discoid counterparts, with a much broader distribution, arguing against dehydration as their origin. The concentration distribution of the polymer-laden sickled cells is significantly higher in mean value, and their volume distributions indicate some dehydration. Previous assumptions about ISCs may have thus been colored by the presence of sickle cells that did contain polymer, and true ISCs may be much more benign than once thought, which underscores the importance of accurate measurement on individual cells. This method could be used to follow changes in individual cell properties under various specific perturbations, and where characterization by flow cytometry is infeasible.

Amorphophallus samarensis (Araceae), a new species endemic to Samar Island, Eastern Visayas, Philippines

Amorphophallus samarensis is described as a new species from Paranas, Samar Island Natural Park, Samar Eastern Visayas, Philippines. A. samarensis resembles A. calcicola by having a solitary leaf, long peduncled solitary flower, cylindric female zone, ovary depressed, disk shape, slightly distant ovaries, and absence of staminode. It differs from A. calcicola by having the rachis winged at the distal part of the leaf, pale to dark maroon slightly depressed globose capitate stigma, style color, length of spadix, and truncate anther. The new species is considered Critically Endangered (CR) based on IUCN guidelines due to persistent anthropogenic activities. There are 30 individual plants encountered in the locality with less than 100 sq. km area of occupancy with an observed threat.

Terahertz quasi-optics imaging systems with easy zoom based on beam-shaping devices and a freeform lens.

Terahertz (THz) waves show outstanding application value in the nondestructive detection of hidden targets that are impenetrable to visible light. However, the uncertain location of hidden targets puts a higher demand on the zoom function of the THz quasi-optical systems, especially when the object is immovable. This paper proposes a continuous zoom system working in the THz band consisting of a negative axicon disk, a segmented axicon, and a freeform lens. The negative axicon disk and segmented axicon shape THz waves into annular beams with adjustable diameters, which are respectively focused at different positions by the zone-designed freeform lens. Both simulation and experimental results indicate that the zoom range of the system can reach 82 mm while maintaining an imaging resolution of 6 mm. Notably, continuous zooming is achieved by merely rotating the negative axicon disk, instead of the lens moving. Moreover, all devices in the system can be fabricated by 3D printing or machining. This approach offers the advantages of simple adjustment and low cost, providing, to our knowledge, a novel perspective for the design and application of THz quasi-optical imaging systems.

Disk Shape Design of Liquid Hydrogen Needle Valve with Various Inherent Flow Characteristics

Disk Shape Design of Liquid Hydrogen Needle Valve with Various Inherent Flow Characteristics

Disk Shape Design of Liquid Hydrogen Needle Valve with Various Inherent Flow Characteristics

Disk Shape Design of Liquid Hydrogen Needle Valve with Various Inherent Flow Characteristics

Neuronal Membrane-Derived Nanodiscs for Broad-Spectrum Neurotoxin Detoxification.

Neurotoxins pose significant challenges in defense and healthcare due to their disruptive effects on nervous tissues. Their extreme potency and enormous structural diversity have hindered the development of effective antidotes. Motivated by the properties of cell membrane-derived nanodiscs, such as their ultrasmall size, disc shape, and inherent cell membrane functions, here, we develop neuronal membrane-derived nanodiscs (denoted "Neuron-NDs") as a countermeasure nanomedicine for broad-spectrum neurotoxin detoxification. We fabricate Neuron-NDs using the plasma membrane of human SH-SY5Y neurons and demonstrate their effectiveness in detoxifying tetrodotoxin (TTX) and botulinum toxin (BoNT), two model toxins with distinct mechanisms of action. Cell-based assays confirm the ability of Neuron-NDs to inhibit TTX-induced ion channel blockage and BoNT-mediated inhibition of synaptic vesicle recycling. In mouse models of TTX and BoNT intoxication, treatment with Neuron-NDs effectively improves survival rates in both therapeutic and preventative settings. Importantly, high-dose administration of Neuron-NDs shows no observable acute toxicity in mice, indicating its safety profile. Overall, our study highlights the facile fabrication of Neuron-NDs and their broad-spectrum detoxification capabilities, offering promising solutions for neurotoxin-related challenges in biodefense and therapeutic applications.

The Effect of 3D Printing Layer Thickness and Post-Polymerization Time on the Flexural Strength and Hardness of Denture Base Resins

Purpose: This study evaluates and compares the effect of printing layer thickness (LT) and post-polymerization time (PPT) on the flexural strength and hardness of three 3D-printed resins after thermal aging. Methods: A bar shape (64 × 10 × 3.3 mm) and a disc shape (15 × 2 mm) were designed for flexural strength and hardness testing, respectively. ASIGA, NextDent, and FormLabs 3D-printed resins were used to print specimens with different LTs (25 µm, 50 µm, and 100 µm). Each thickness group was post-polymerized (PP) for different times (15, 30, 60, and 90 min). All printed specimens were thermally cycled (5000 cycles) and then tested, measuring the flexural strength and hardness using a universal testing machine and Vickers hardness tester, respectively. The data were analyzed using ANOVA and a post hoc Tukey’s test (α = 0.05). Results: A PPT of 90 min showed the highest flexural strength. In comparisons of the LTs, 25 µm and 50 µm significantly increased flexural strength compared with 100 µm, which showed the lowest value for each PPT. The hardness increased as the PPT increased for all materials. In our LT comparison, 25 µm and 50 µm significantly increased the hardness for NextDent and FormLabs resins, while only 25 µm showed high hardness compared with 50 µm and 100 µm for ASIGA. Conclusion: Both parameters (LT and PPT) impact flexural strength and hardness. Increased PPT with the minimum LT is recommended.

The Additive to Mass Manufacturing Process of Mixed Potential Electrochemical Sensors

Additive manufacturing allows for quick turn around and low cost of production of small numbers of parts. These attributes lend the technology to prototype development, where design changes are many and production numbers are low [1]. Once design parameters have been nailed down, additive manufacturing’s low throughput and poor reproducibility limit application to high volume production.Here, we discuss the implementation of direct-write extrusion of ceramic pastes and metal inks for prototype manufacturing of mixed potential electrochemical sensors and the transition to tape casting and screen printing for high volume production. Throughout the prototyping phase, direct write extrusion enabled quick and easy production of low numbers of parts, enabling various changes in sensor design and material to improve sensor performance. Sensor design evolved from a disk shape (Fig. 1 a) to a stick with integrated heater (Fig. 1 b, c). Direct write extrusion of substrate enabled quick testing of various stabilized zirconia ceramics to improve the sensitivity of the device [2]. Limitations of additive manufacturing became apparent when attempting to integrate the heater into the device, the inconsistent linewidths led to areas of high resistance and hot spots (Fig. 1 c). Tape-casting and screen printing of the devices was adopted for three reasons, first, to improve line fidelity, which is vitally important when printing small electrodes as well as heater traces (Fig. 1 d), second, to further decrease conductivity of substrate by laminating multiple layers of different ceramic materials, and finally to increase manufacturing throughput (Fig. 1 d, e).This work was supported by US Department of Energy Award DE-FE0031864References[1] T. D. Ngo, A. Kashani, G. Imbalzano, K. T. Q. Nguyen, and D. Hui, “Additive manufacturing (3D printing): A review of materials, methods, applications and challenges,” Compos. Part B Eng., vol. 143, pp. 172–196, Jun. 2018, doi: 10.1016/j.compositesb.2018.02.012.[2] S. Halley, K. Ramaiyan, F. Garzon, and L. Tsui, “Massive enhancement in sensitivity of mixed potential sensors towards methane and natural gas through magnesia stabilized zirconia low ionic conductivity substrate,” Sens. Actuators B Chem., vol. 392, p. 134031, Oct. 2023, doi: 10.1016/j.snb.2023.134031. Figure 1

Palmitic acid-mediated modulation of crystallization dynamics in amylose microparticle formation: From spherical to macaron and disc shapes

Here, we investigated the complexation of short chain amylose (SCAs) and palmitic acid (PA), serving as polymeric building blocks that alter the selectivity and directionality of particle growth. This alteration affects the shape anisotropy of the particles, broadening their applications due to the increased surface area. By modifying the concentration of PA, we were able to make spherical, macaron, and disc-shaped particles, demonstrating that PA acts as a structure-directing agent. We further illustrated the lateral and longitudinal stacking kinetics between PA-SCA inclusion complexes during self-assembly, leading to anisotropy. Transmission electron microscope (TEM) and scanning electron microscope (SEM) revealed the structural difference between the initial and final morphologies of palmitic acid-short chain amylose particles (PA-SCAPs) compared to those of short-chain amylose particle (SCAPs). The presence of PA-SCA inclusion complex in the anisotropic particles was confirmed using nuclear magnetic resonance (NMR) and powder x-ray diffraction (XRD) analysis.

Sibling Species Amblyraja hyperborea and A. jenseni in Slope Waters of Eastern Canada: An Ecomorphological Description

Deepwater survey data and specimens collected from the Grand Banks to Baffin Bay in the Northwest Atlantic were used to examine the distribution, morphometrics, meristics and maturity of two siblings, Amblyraja hyperborea and A. jenseni. Our study confirmed that the two species occupy different locations, their distributions separated by Davis Strait, a biogeographic break separating Atlantic from Arctic waters. A. hyperborea with a smaller maximum size and size at maturity inhabited colder Arctic slope waters in Baffin Bay while larger A. jenseni were located in warmer Atlantic slope waters. Despite their distributional separation and thus reproductive isolation, spine counts and body morphology were almost indistinguishable between species. Only upper jaw teeth row count and difference in the size of spines on the mid-rear wings differentiated the two species. Also, for both species, the proportion of dorsal fins joined, disc shape and relative tail length changed with total length. Secondary reproductive anatomy, clasper length and vas deferens weight, shell gland and uterus weight underwent initial acceleration in growth when the gonads transitioned to stage 2 (adolescent, maturing). Also, YOY A. hyperborea were found to distribute at shallower depths than larger stages, constituting a nursery, which was not observed for A. jenseni.

Multipole couplings in dielectric nanodisk arrays and their polarization effects.

In this paper, we study the optical properties of a planar array consisting of nanodisks using the coupled multipole model (CMM). As we demonstrate, this model shows its advantages in uncovering the complex inter-particle mutual interaction mechanisms, which are usually obscured by direct numerical simulations. We first propose a method to compute the polarizabilities of the individual non-spherical particles up to the magnetic quadrupole. Then, the multipole moments of the arrayed nanodisks can be readily calculated. Using the results, we were able to trace the dominant contributions from the various couplings between these multipole sources. From such analysis, we reveal the mechanisms of multipole resonance shifts and possible manipulation strategies. These insights rendered by the CMM make it possible to design the array as a polarizer by tuning the lattice periods. We further evaluated the polarizer performance under different working wavelengths and incident angles. As the disk shape is relatively less challenging for fabrication, our model shows great promise in optimizing and designing functional structures for nano-optics applications.

On the Doublet Flux Ratio of Mg ii Resonance Lines in and Around Galaxies

Observations of metallic doublet emission lines, particularly Mg ii λ λ2796, 2803, provide crucial information for understanding galaxies and their circumgalactic medium. This study explores the effects of resonant scattering on the Mg ii doublet lines and the stellar continuum in spherical and cylindrical geometries. Our findings show that under certain circumstances, resonance scattering can cause an increase in the doublet flux ratio and the escaping flux of the lines beyond what is expected in optically thin spherical media. As expected, the doublet ratio is consistently lower than the intrinsic ratio when the scattering medium is spherically symmetric and dusty. However, if the scattering medium has a disk shape, such as face-on disk galaxies, and is viewed face-on, the doublet ratio is predicted to be higher than 2. It is also shown that doublet ratios as low as those observed in compact star-forming galaxies cannot be explained solely by pure dust attenuation of intrinsic Mg ii emission lines in spherical models unless dust opacity deviates markedly from that expected based on the dust-to-Mg+ gas ratio of our Galaxy. The importance of the continuum-pumped emission lines and expanding media is discussed to understand observational aspects, including doublet flux ratios, which can be lower than 1.5 or higher than 2, as well as symmetric or asymmetric line profiles. It is also discussed that the diffuse warm neutral medium may be an important source of Mg ii emission. These results provide insight into the complexity of the shape and orientation of distant, spatially unresolved galaxies.

Sexual dimorphism in the dwarf round ray Urotrygon nana.

This paper presents information on the morphological, morphometric, and dental sex differences in the dwarf round ray Urotrygon nana. We recorded 12 morphological traits, sex, the distribution pattern of dermal denticles, the number of tooth rows, and the tooth shape of 466 individuals. The disc width of females ranged from 50 to 172 mm and that of males ranged from 53 to 135 mm. A neuronal classification model and a correspondence analysis showed that female disc width was 21.5% broader, and the distance from the rostrum to the anus was 17.7% longer than that of males, whereas males presented 19.5% greater distance between the nostrils, 9.7% greater preorbital snout length, 6.8% greater cloaca to caudal-fin length, 2.7% greater interorbital distance, and 1.1% greater total length than females. The disc of adult males, including the abdominal cavity area, was densely covered with dermal denticles, which were slightly larger than those observed in females. Females presented homodont dentition with molariform teeth and a smooth lozenge-shaped crown with rounded margins. Males exhibited homodonty but with tooth morphology variations in individuals of different sizes (from molariforms to sharper cusp teeth). There were changes in disc shape (from subcircular to oval), distribution and size of dermal denticles (more abundant and larger), and tooth shape (from molariform to monocuspid teeth) during male development, from neonates to adults. U. nana exhibited sexual dimorphism in size, disc shape, number and shape of teeth, and distribution and size of dermal denticles.

Analytical justifications of constructive parameters of bionic colters for vertical soil treatment

Bionic coulters imitate natural forms and functions, which help reduce energy costs for soil tillage. The aim of the research was to justify the design and structural parameters of turbo discs (coulters) for vertical tillage based on the principles of bionic reverse engineering. Using this method, an equation for the shape of the turbo discs (coulters) was derived, which was obtained by approximating the shell of the argonaut (Argonauta argo). The equation takes into account the main structural parameters of the turbo discs: diameter Dd, cutout height Hm, wave height Hw, number of cutouts n, and spiral coefficient k. As a result of analytical studies on the interaction process between a solid disc and plant residues, the optimal diameter value was determined to be Dd=460 mm under the condition of submerging stems with a thickness of 10-20 mm to a depth of 80 mm. The analytical studies confirmed that the presence of cutouts on the disc prevents stem deflection and ensures better stem capture. In analysing the obtained dependencies using the Wolfram Cloud software package, the optimal values for the cutouts were determined: cutout height Hm=40 mm, number of cutouts n=8. The presence of waves on the disc surface ensures that the interaction with plant residues is independent of their position on the field surface and creates conditions for vertical soil tillage. It was found that, to minimize specific cutting resistance and maximize the degree of soil fragmentation, the optimal wave parameters for the coulter are a wave height of Hw=24.4 mm. The justified parameters of the coulters provide the best balance between soil fragmentation efficiency and reduction in energy consumption for soil tillage. The obtained results can be used to adapt existing agricultural machinery to the new structural parameters of coulters to improve its efficiency.

Tricompartmental Microcarriers with Controlled Release for Efficient Management of Parkinson's Disease.

Parkinson's is a progressive neurodegenerative disease of the nervous system. It has no cure, but its symptoms can be managed by supplying dopamine artificially to the brain.This work aims to engineer tricompartmental polymeric microcarriers by electrohydrodynamic cojetting technique to encapsulate three PD (Parkinson's disease) drugs incorporated with high encapsulation efficiency (∼100%) in a single carrier at a fixed drug ratio of 4:1:8 (Levodopa (LD): Carbidopa(CD): Entacapone (ENT)). Upon oral administration, the drug ratio needs to be maintained during subsequent release from microparticles to enhance the bioavailability of primary drug LD. This presents a notable challenge, as the three drugs vary in their aqueous solubility (LD > CD > ENT). The equilibrium of therapeutic release was achieved using a combination of FDA-approved polymers (PLA, PLGA, PCL, and PEG) and the disc shape of particles. In vitro studies demonstrated the simultaneous release of all the three therapeutics in a sustained and controlled manner. Additionally, pharmacodynamics and pharmacokinetics studies in Parkinson's disease rats induced by rotenone showed a remarkable improvement in PD conditions for the microparticles-fed rats, thereby showing a great promise toward efficient management of PD.

A comprehensive study of carbon nanoparticle shape and orientation effects on composite elastic properties using FEA

In this study, three critical parameters that influence the effective composite properties of Carbon nanoparticles were tested and modeled using finite elements through Digimat Finite Element Analysis (FEA) software, employing representative volume elements (RVE). The primary parameters under consideration are the fiber shape, fiber orientation, and fiber volume fraction. Four of the many different shapes of Carbon nanoparticles, namely Tubes, Disk, Sphere, and Cylinder, were investigated, coupled with four distinct orientations for tubes: horizontal, aligned at 45°, random, and vertical each varying in the carbon fiber volume fraction. The material of choice was pure epoxy resin because of the nature of the bonding between its two phases and its wide range of usage. Forces were applied along the X-axis, coupled with shear in the XY plane. This study revealed that the orientation of CNTs primarily influences the Elastic Young’s modulus, whereas the size of the CNTs has the main effect on the shear modulus, followed by orientation. The horizontal CNTs demonstrated superior Young’s modulus, but the random orientation had a more pronounced impact on the shear modulus variation. Regarding the analysis of the nanoparticles shapes, the disk shape with fixed orientation revealed the highest elastic modulus, after which the cylinder shape and the sphere recorded the minimum elastic modulus among the three studied shapes.

Impact of surface treatment and addition of CuO NPs of surface roughness of acrylic denture base bonded to soft liner

Background: The import of the rough surface makes the application of several elements to enhance this feature vital for the adhesion of soft liners. Aim: The study's goal was to to ascertain the impact of copper oxide nanoparticles added in two ratios to heated-cured acrylic resin and fiber laser surface treatment on surface roughness. Materials and methods:60 acrylic specimens in the shape of discs were manufactured and divided into three groups: one received no addition; the other two received the addition of 0.3% CuO NPs; and a third group that received the addition of 0.5% CuO NPs. Each group was divided into two categories: those that were laser treatment and those who did not. The surface roughness test was then examined using a roughness tester called a profilometer. Results: The average roughness values were high for the control groups and low for the CuO NPs 0.5% groups. The mean values in the laser-treated groups had greater roughness than the control groups, according to the laser application.Conclusion:. As the fraction of CuO NPs increased, the surface roughness reduced. The laser treatment also reduced surface roughness.