Orientation Alignment Research Articles

Study on Properties of Additive Manufacturing Ta10W Alloy Laser-Welded Joints

This investigation focuses on Selective Laser Melting (SLM)-fabricated thin-walled Ta10W alloy components. Given the inherent limitations of SLM in producing large-scale, complex components in a single operation, laser welding was investigated as a viable secondary processing method for component integration. The study addresses the critical issue of weldability in additively manufactured tantalum-tungsten alloys, which frequently exhibit internal defects due to process imperfections. Comprehensive analyses were conducted on weldability, microstructural evolution, texture intensity, and mechanical properties for welds oriented along both traveling and building directions. Results demonstrate that welds oriented along the traveling direction exhibit superior performance characteristics, including enhanced tensile strength, increased yield strength, improved elongation, and reduced texture intensity compared to building direction welds. Notably, grain orientation alignment between the weld zone and base material was observed consistently in both directional configurations.

Effect of steel fibers on the stress–strain behaviour of aligned steel fiber ultra-high performance concrete under uniaxial compression

The mechanical properties of ultra-high performance concrete (UHPC) can be significantly enhanced by aligning the fibers. Aligned steel fiber UHPC (ASF-UHPC) was fabricated using a uniform magnetic field, yet the corresponding stress-strain relationship has not been extensively studied, hindering accurate calculations. To address this gap, ASF-UHPC was prepared and subsequently subjected to CT scans and uniaxial compression tests to investigate its stress-strain behavior. The analysis of failure mode and stress-strain curves revealed distinct anisotropic characteristics in compressive stresses and fiber distributions. Various steel fiber parameters, including the alignment orientation, volume fraction, and length, were systematically analysed to assess their impact on the material properties. A unit-cell model was developed to elucidate the influence of the fiber alignment orientation on UHPC performance. The results demonstrate that a parallel fiber alignment significantly enhances the elastic modulus, albeit with a Poisson ratio similar to that of the matrix, owing to the limited lateral confinement. Conversely, perpendicular fiber alignment restrains lateral deformation, enhancing the material strength and toughness. Randomly distributed fibers offered a degree of horizontal confinement, whereas inclined fibers induced horizontal thrust, leading to excessive lateral deformation and consequent elevation of the Poisson ratio. Finally, predictive equations for UHPC elastic modulus and compressive strength, along with an analysis model for stress-strain characteristics, were refined taking into account the direction of fiber arrangement.

Osteogenic tailoring of oriented bone matrix organization using on/off micropatterning for osteoblast adhesion on titanium surfaces.

Titanium (Ti) implants are well known for their mechanical reliability and chemical stability, crucial for successful bone regeneration. Various shape control and surface modification techniques to enhance biological activity have been developed. Despite the crucial importance of the collagen/apatite bone microstructure for mechanical function, antimicrobial properties, and biocompatibility, precise and versatile pattern control for regenerating the microstructure remains challenging. Here, we developed a novel osteogenic tailoring stripe-micropatterned MPC-Ti substrate that induces genetic-level control of oriented bone matrix organization. This biomaterial was created by micropatterning 2-methacryloyloxyethyl phosphorylcholine (MPC) polymer onto a titanium (Ti) surface through a selective photoreaction. The stripe-micropatterned MPC-Ti substrate establishes a distinct interface for cell adhesion, robustly inducing osteoblast cytoskeleton alignment through actin cytoskeletal alignment, and facilitating the formation of a bone-mimicking-oriented collagen/apatite tissue. Moreover, our study revealed that this bone alignment process is promoted through the activation of the Wnt/β-catenin signaling pathway, which is triggered by nuclear deformation induced by strong cellular alignment guidance. This innovative material is essential for personalized next-generation medical devices, offering high customizability and active restoration of the bone microstructure. STATEMENT OF SIGNIFICANCE: This study demonstrates a novel osteogenic tailoring stripe-micropatterned MPC-Ti substrate that induces osteoblast alignment and bone matrix orientation based on genetic mechanism. By employing a light-reactive MPC polymer, we successfully micropatterned the titanium surface, creating a biomaterial that stimulates unidirectional osteoblast alignment and enhances the formation of natural bone-mimetic anisotropic microstructures. The innovative approach of regulating cell adhesion and cytoskeletal alignment activates the Wnt/β-catenin signaling pathway, crucial for both bone differentiation and orientation. This study presents the first biomaterial that artificially induces the construction of mechanically superior anisotropic bone tissue, and it is expected to promote functional bone regeneration by enhancing bone differentiation and orientation-targeting both the quantity and quality of bone tissue.

Change in standing acetabular orientation 2 years postoperatively after surgical correction of adult spinal deformity.

Although sagittal alignment is known to influence pelvic position, few studies accurately identify the relationship between sagittal alignment and acetabular orientation. We hypothesized that postoperative PT should be correlated with acetabular change in native hips after surgical correction of adult spinal deformity. The objective of this study was therefore to describe the correlation between the change in pelvic tilt and the change in acetabular orientation two years after surgical correction of adult spinal deformity. Based on a retrospective study of a prospective mono center database, 127 acetabuli out of sixty-nine patients were analyzed preoperatively and at two years postoperatively of surgical management of sagittal imbalance by posterior arthrodesis extended to the pelvis. The analysis was based on bi-planar EOS radiographs with 3D reconstructions of the pelvis and spine using SterEOS 3D software. The following specific parameters were analyzed: sacral slope, pelvic tilt, lumbar lordosis, SVA, acetabulum tilt (AT), anteversion (AA) (orientation of the acetabulum in the axial plane), abduction (AAbd) (orientation of the acetabulum in the frontal plane), inclination (AI) (orientation of the acetabulum in the sagittal plane), and anterior acetabulum coverage (ACA). A Pearson correlation was performed between the pre-and postoperative change in acetabular parameters (right and left) and pelvic parameters. Linear regressions were performed to identify the most relevant pelvic and spinal parameters. A subgroup analysis was performed to identify a difference between distal sacral and distal ilium fixations. All measured acetabular parameters were significantly different two years after surgery. Changes in AT (p = 0.03), AI (p = 0.03) and ACA (p = 0.05) were significantly greater in the ilium fixation group. Postoperative PT reduction was strongly correlated with the decrease of AT and AA ( = 0.61 and = 0.57, p < 0.001), it was also correlated with the increase of AI and ACA and the decrease of AAbd. The entire cohort linear regression analysis revealed that a 1 ° decrease in PT resulted in a 0.4 ° decrease in AA and a 0.6 ° decrease in AT (R2 = 0.45 and = 0.38). Our study highlights the significant influence of the change in sagittal alignment on acetabular orientation in standing position. This correlation explains the increased risk of anterior hip impingement, the change in acetabular load distribution that might lead to early hip osteoarthritis, and the overall change in the subjects' gait pattern. IV.

Fully Automatic Geometric Registration Framework of UAV Imagery Based on Online Map Services and POS

Unmanned aerial vehicle (UAV) remote sensing has found extensive applications in various fields due to its ability to quickly provide remote sensing imagery, and the rapid, even automated, geometric registration of these images is an important component of their time efficiency. While current geometric registration methods based on image matching are well developed, there is still room for improvement in terms of time efficiency due to the presence of the following factors: (1) difficulty in accessing historical reference images and (2) inconsistencies in data sources, scales, and orientations between UAV imagery and reference images, which leads to unreliable matching. To further improve the time efficiency of UAV remote sensing, this study proposes a fully automatic geometric registration framework. The workflow features the following aspects: (1) automatic reference image acquisition by using online map services; (2) automatic ground range and resolution estimation using positional and orientation system (POS) data; (3) automatic orientation alignment using POS data. Experimental validation demonstrates that the proposed framework is able to carry out the fully automatic geometric registration of UAV imagery, thus improving the time efficiency of UAV remote sensing.

3D Crystal Construction by Single-Crystal 2D Material Supercell Multiplying.

2D stacking presents a promising avenue for creating periodic superstructures that unveil novel physical phenomena. While extensive research has focused on lateral 2D material superstructures formed through composition modulation and twisted moiré structures, the exploration of vertical periodicity in 2D material superstructures remains limited. Although weak van der Waals interfaces enable layer-by-layer vertical stacking, traditional methods struggle to control in-plane crystal orientation over large areas, and the vertical dimension is constrained by unscalable, low-throughput processes, preventing the achievement of global order structures. In this study, a supercell multiplying approach is introduced that enables high-throughput construction of 3D superstructures on a macroscopic scale, utilizing artificially stacked single-crystalline 2D multilayers as foundational repeating units. By employing wafer-scale single-crystalline 2D materials and referencing the crystal orientation of substrates, the method ensures precise alignment of crystal orientation within and across each supercell, thereby achieving controllable periodicity along all three axes. A centimeter-scale 3R-MoS₂ crystal is successfully constructed, comprising over 200 monolayers of single-crystalline MoS₂, through a bottom-up stacking process. Additionally, the approach accommodates the integration of amorphous oxide, enabling the assembly of 3D non-linear optical crystals with quasi-phase matching. This method paves the way for the bottom-up construction of macroscopic artificial 3D crystals with atomic plane precision, enabling tailored optical, electrical, and thermal properties and advancing the development of novel artificial materials and high-performance applications.

Improving thermal conductivity of butylpyridine latex‐based composites by modified single‐layer graphene

AbstractChelated titanate (CT) modified single‐layer graphene (CTMSG), exhibiting much better static and dynamic stability due to the synergy of physical and chemical bonds, was mixed with butadiene‐vinylpyridine latex (BL) to prepare composite (CTMSG‐BL) film to enhance its thermal conductivity. Furthermore, CTMSG‐BL was complexed with polyethylene terephthalate (PET) fabric to promote the thermal conductivity of the composite (CTMSG‐BL/PET). Compared with the samples without CTMSG, the thermal conductivity of CTMSG‐BL (CTMSG content: 0.2 wt%) and CTMSG‐BL/PET increased from 3.52 to 4.35 W/(m·K) and from 1.91 to 2.56 W/(m·K), improved by 19.1% and 34.0%. This benefits from the excellent orientation alignment of single‐layer graphene (SG) in BL film and the highly efficient construction of the thermal conductivity pathway. The CTMSG‐BL emulsion is suitable for preparing heat‐resistant thermal conductive film with a thickness of micro‐nano meter (~0.6 μm) by impregnation process because of the low viscosity of the CTMSG‐BL emulsion (3.61 mPa·s) and the good heat resistance of the pyridine groups of BL with average pyrolysis temperature about 444 °C. The CTMSG‐BL film and CTMSG‐BL/PET composites have excellent heat conduction and dissipation properties, exhibiting broad application prospects in thermal interface materials, aerospace, and transport.Highlights The static and dynamic stability of the CTMSG was significantly improved. Low viscosity CTMSG‐BL is suitable for preparing thermally conductive films. With the addition of CTMSG, the thermal conductivity of BL improved by 19.0%. With addition of CTMSG, the thermal conductivity of BL/PET improved by 34%.

Distributed formation tracking with connectivity preservation and orientation alignment

This paper investigates the formation tracking problem incorporating connectivity preservation and orientation alignment for multi-agent systems. Consider the body-fixed frame of each agent in the multi-agent system is initialized with different orientations. To achieve formation controller design by relative position in the body-fixed frame, the orientation of the frames should be aligned first. A distributed passive-based orientation controller is proposed to ensure convergence of all body-fixed frames toward a unified desired orientation. Once the frames are aligned, a barrier Lyapunov function (BLF)-based formation tracking controller is proposed utilizing the displacement of the agent to ensure the distances between agents always satisfy predefined distance constraints. This strategy guarantees inter-agent collision avoidance and connectivity preservation throughout the formation. Numerical simulations are conducted to validate the efficacy of the proposed approach.

Analysis of Thermoelectric Properties of Hot-deformed Bismuth Telluride Sintered Materials

Bismuth telluride (Bi2Te3)-based alloys are widely used for thermoelectric cooling and power generation at low temperatures, and they are the only commercially available materials for thermoelectric applications below 500 K. The rhombohedral unit cell with a large c/a lattice constant ratio consisting of - Te-Bi-Te-Bi-Te- stacked layers inevitably brings about a large anisotropy in transport properties, which is why texturing is very important in polycrystalline Bi2Te3&lt;/sub alloys for maximum performance. In this report, p and n-type polycrystalline Bi2Te3&lt;/sub alloys were synthesized and hot-deformed to investigate the effects of texturing on thermoelectric properties. Hot deformation (HD) induces the strong alignment of (001) orientations along the compression direction, and a remarkable increase in the orientation factor F of (001) orientations is observed after HD in both p and n-type materials. All of the hot-deformed polycrystalline samples showed increased electrical conductivity (σ), power factor (PF), and thermal conductivity (k) in the in-plane (IP) direction, and vice versa in the out-of-plane (OOP) direction, which makes the IP direction of the hot-deformed bodies more favorable for module fabrication in terms of power factor, for both p and n-type Bi2Te3&lt;/sub-based alloys. However, due to the different degree of anisotropy of k and σ, the figures of merit (zT) were maximized in the OOP direction in the p-type materials after HD, whereas the zTs of the n-type materials were higher in the IP direction. This occurs because the anisotropy factor of electron conduction is higher than that of hole conduction, which more than offsets the advantage of the smaller k in the c-direction of n-type Bi2Te3&lt;/sub. The maximum zT of 1.33 (OOP) and 0.90 (IP) were obtained after HD from the p and n-type Bi2Te3 alloys, respectively, which were 9.3% and 18.4% higher than those of as-sintered materials.

A Spin‐Polarized Electron‐Induced MXene‐KBi0.9Co0.1Fe2O5 Photocatalyst for Enhanced Dye Degradation

In photocatalysts aimed to degrade environmental pollutants, photons are generally used as primary stimuli to generate electron–hole pairs to target the chemical bonds to disintegrate. Recently, electron spin has been reported as an essential degree of freedom to improve the performance of photocatalysts. In this work, spin‐polarized electrons and holes are introduced into a brownmillerite KBi0.9Co0.1Fe2O5 semiconductor and a two‐dimensional (2D) MXene composite system by application of an external magnetic field. The spin polarization properties are monitored by measuring the magnetoresistance effect of the MXene‐KBCFO device, which is related to the carrier transfer efficiency. Remarkably, the photocatalytic performance of MXene‐KBCFO is significantly enhanced by the simultaneous application of an external magnetic field and illumination due to the increased number of spin‐polarized photoexcited carriers caused by the synergy effect of the 2D MXene heterostructure together with the ferromagnetic spin ordering. This results in increased reaction hotspots, effective built‐in electric field, extended carrier lifetime, and reduced charge recombination owing to parallel alignment of electron spin orientation. The results show that the efficiency and stability of photocatalytic dye degradation can be effectively enhanced by manipulating the spin‐polarized electrons in the MXene‐based oxide‐perovskite heterostructure photocatalyst.

Effect of solution temperature on the microstructure of 2:17 type SmCo magnets

The exceptional magnetic properties of 2:17 type SmCo magnet material is the results of its unique cellular structure. We conducted a systematic analysis of the evolution of the solid solution temperature on the microstructure of both the solid solution precursor and the final magnet, and revealed the distribution of elements affect by the magnet's properties. The findings show that a considerable number of short-range low-order microregions are observed with discontinuous alignment orientations, and overlapping zones are produced in the solid solution precursor by low-temperature solid solutions. The aging process makes these regions challenging to organize, and a lot of 2:17 R phases form close to 1:5 H cell boundary phase and grain boundary, which impedes the enhancement of magnetic characteristics. Increasing the solution temperature promotes the diffusion of Cu and Fe elements, accelerating the ordering of the 2:17 R phase and aiding in the creation of a cellular structure. The phase evolution of the 2:17 type SmCo magnet can be better understand by referring to the previously conducted research on the impact of solid solution temperature on the microstructure of the solid solution precursor and final magnet.

Ultrastable piezoelectric biomaterial nanofibers and fabrics as an implantable and conformal electromechanical sensor patch.

Poly(l-lactic acid) (PLLA) is a widely used U.S. Food and Drug Administration-approved implantable biomaterial that also possesses strong piezoelectricity. However, the intrinsically low stability of its high-energy piezoelectric β phase and random domain orientations associated with current synthesis approaches remain a critical roadblock to practical applications. Here, we report an interfacial anchoring strategy for fabricating core/shell PLLA/glycine (Gly) nanofibers (NFs) by electrospinning, which show a high ratio of piezoelectric β phase and excellent orientation alignment. The self-assembled core/shell structure offers strong intermolecular interactions between the -OH groups on Gly and C=O groups on PLLA, which promotes the crystallization of oriented PLLA polymer chains and stabilizes the β phase structure. As-received core/shell NFs exhibit substantially enhanced piezoelectric performance and excellent stability. An all NF-based nonwoven fabric is fabricated and assembled as a flexible nanogenerator. The device offers excellent conformality to heavily wrinkled surfaces and thus can precisely detect complex physiological motions often found from biological organs.

Atomically self-healing of structural defects in monolayer WSe2

Abstract Minimizing disorder and defects is crucial for realizing the full potential of two-dimensional transition metal dichalcogenides (TMDs) materials and improving device performance to desired properties. However, the methods in defect control currently face challenges with overly large operational areas and a lack of precision in targeting specific defects. Therefore, we propose a new method for the precise and universal defect healing of TMD materials, integrating real-time imaging with scanning transmission electron microscopy (STEM). This method employs electron beam irradiation to stimulate the diffusion migration of surface-adsorbed adatoms on TMD materials grown by low-temperature molecular beam epitaxy (MBE), and heal defects within the diffusion range. This approach covers defect repairs ranging from zero-dimensional vacancy defects to two-dimensional grain orientation alignment, demonstrating its universality in terms of the types of samples and defects. These findings offer insights into the use of atomic-level focused electron beams at appropriate voltages in STEM for defect healing, providing valuable experience for achieving atomic-level precise fabrication of TMD materials.

Self-assembly of metal-organic framework (UIO-66-NO2) and MXene for wearable and high-performance flexible pressure sensor

Wearable sensor technology has garnered increasing attention among researchers. In this study, the porous metal-organic framework containing nitroxide (UIO-66-NO2) is pasted onto MXene by hydrogen bonding and then incorporated into PVDF-HFP for electrospinning to fabricate piezoelectric membranes. The porous structure of the metal-organic frameworks significantly contributes to the alignment of electric domain orientation within the piezoelectric membranes post-polarization, and the nitro of UIO-66-NO2 helps to enhance the inductive power effect of the sensor, the piezoelectric constant of the composite piezoelectric membrane reaches 26.1 pC/N, 5.8 times that of the pure PVDF-HFP membrane (4.5 pC/N). The sensitivity reaches 20.99 V/N, which is 5.75 times that of the pure PVDF-HFP sensor (3.65 V/N). We conduct an exploration into the potential mechanisms behind the enhanced piezoelectric properties resulting from the incorporation of MXene and the metal-organic framework. The fabricated flexible pressure sensor exhibits commendable cyclic stability, boasting rapid response and recovery time (20/10.8 ms). The sensor demonstrates the capability to monitor human respiration and pulse, discern various parts of the human body and their respective amplitudes, differentiate between different materials, the pressure sensor has potential applications in human-computer interaction and health monitoring.

Chemically tailored block copolymers for highly reliable sub-10-nm patterns by directed self-assembly

While block copolymer (BCP) lithography is theoretically capable of printing features smaller than 10 nm, developing practical BCPs for this purpose remains challenging. Herein, we report the creation of a chemically tailored, highly reliable, and practically applicable block copolymer and sub-10-nm line patterns by directed self-assembly. Polystyrene-block-[poly(glycidyl methacrylate)-random-poly(methyl methacrylate)] (PS-b-(PGMA-r-PMMA) or PS-b-PGM), which is based on PS-b-PMMA with an appropriate amount of introduced PGMA (10–33 mol%) is quantitatively post-functionalized with thiols. The use of 2,2,2-trifluoroethanethiol leads to polymers (PS-b-PGFMs) with Flory–Huggins interaction parameters (χ) that are 3.5–4.6-times higher than that of PS-b-PMMA and well-defined higher-order structures with domain spacings of less than 20 nm. This study leads to the smallest perpendicular lamellar domain size of 12.3 nm. Furthermore, thin-film lamellar domain alignment and vertical orientation are highly reliably and reproducibly obtained by directed self-assembly to yield line patterns that correspond to a 7.6 nm half-pitch size.

Highly Regular Layered Structure via Dual-Spatially-Confined Alignment of Nanosheets Enables High-Performance Nanocomposites.

Assembling ultrathin nanosheets into layered structure represents one promising way to fabricate high-performance nanocomposites. However, how to minimize the internal defects of the layered assemblies to fully exploit the intrinsic mechanical superiority of nanosheets remains challenging. Here, a dual-scale spatially confined strategy for the co-assembly of ultrathin nanosheets with different aspect ratios into a near-perfect layered structure is developed. Large-aspect-ratio (LAR) nanosheets are aligned due to the microscale confined space of a flat microfluidic channel, small-aspect-ratio (SAR) nanosheets are aligned due to the nanoscale confined space between adjacent LAR nanosheets. During this co-assembly process, SAR nanosheets can flatten LAR nanosheets, thus reducing wrinkles and pores of the assemblies. Benefiting from the precise alignment (orientation degree of 90.74%) of different-sized nanosheets, efficient stress transfer between nanosheets and interlayer matrix is achieved, resulting in layered nanocomposites with multiscale mechanical enhancement and superior fatigue durability (100000 bending cycles). The proposed co-assembly strategy can be used to orderly integrate high-quality nanosheets with different sizes or diverse functions toward high-performance or multifunctional nanocomposites.

AlN: An Engineered Thermal Material for 3D Integrated Circuits

AbstractAluminum nitride (AlN) is a promising material for thermal management in 3D integrated circuits (ICs) due to its high thermal conductivity. However, achieving high thermal conductivity in AlN thin films grown at low temperatures on amorphous substrates poses significant challenges for back‐end‐of‐line (BEOL) compatibility. This study reports high cross‐plane thermal conductivities approaching 90 Wm−1K−1 for sub‐300 nm‐thick AlN films sputter‐deposited at low temperatures (&lt;200 °C) on ordinary SiO2 substrates. The correlations between cross‐plane and in‐plane thermal conductivity, texture, grain size, oxygen content, Al:N atomic ratio, and thermal boundary conductance of these films are explored. These findings reveal the crucial role of grain orientation alignment in achieving high thermal conductivity and high thermal boundary conductance. A method is introduced to effectively monitor the thermal conductivity of the AlN thin films using X‐ray diffraction. This study offers valuable insights that can aid in the implementation of an effective thermal management material in the semiconductor production line.

Orientational alignment of semiconducting carbon nanotubes by the parallel steps of high-index copper foils

Numerous research efforts have focused on the deposition and morphology control of semiconducting single-walled carbon nanotubes (s-SWCNTs) to exploit their extraordinary properties to fulfill in building next-generation electronics. However, it is difficult to realize s-SWCNT arrays at the controlled densities and alignments desired for high-performance devices. Here, we developed a novel approach to control the morphology and alignment of s-SWCNTs. Random s-SWCNT networks came into being well-aligned s-SWCNT arrays (within the alignment of 16.9°) along with the recrystallization of copper foils from polycrystalline to single-crystalline. Grain boundary migration induced motion and alignment of s-SWCNTs. In this way, high-quality s-SWCNTs were assembled into well-aligned CNT arrays on single-crystal high-index copper foils. Furthermore, theoretical calculations confirm that the strong binding energy between the s-SWCNTs and the copper edge steps leads to the orientational alignment of the s-SWCNTs on the copper surface.

Flexible, biodegradable ultrasonic wireless electrotherapy device based on highly self-aligned piezoelectric biofilms.

Biodegradable piezoelectric devices hold great promise in on-demand transient bioelectronics. Existing piezoelectric biomaterials, however, remain obstacles to the development of such devices due to difficulties in large-scale crystal orientation alignment and weak piezoelectricity. Here, we present a strategy for the synthesis of optimally orientated, self-aligned piezoelectric γ-glycine/polyvinyl alcohol (γ-glycine/PVA) films via an ultrasound-assisted process, guided by density functional theory. The first-principles calculations reveal that the negative piezoelectric effect of γ-glycine originates from the stretching and compression of glycine molecules induced by hydrogen bonding interactions. The synthetic γ-glycine/PVA films exhibit a piezoelectricity of 10.4 picocoulombs per newton and an ultrahigh piezoelectric voltage coefficient of 324 × 10-3 volt meters per newton. The biofilms are further developed into flexible, bioresorbable, wireless piezo-ultrasound electrotherapy devices, which are demonstrated to shorten wound healing by ~40% and self-degrade in preclinical wound models. These encouraging results offer reliable approaches for engineering piezoelectric biofilms and developing transient bioelectronics.

The influence of immediate occlusal loading on micro/nano-structure of peri-implant jaw bone in rats

PurposeThe objective of the present study was to ascertain the effect of immediate occlusal loading after implant placement on osseointegration and the micro/nanostructure of the surrounding bone.MethodsAfter extraction of a rat maxillary right second molar, an implant was placed immediately with initial fixation (2 N< ). The implants were placed to avoid occlusal loading due to mastication, and in the loaded group, a superstructure was fabricated and subjected to occlusal loading. Bone morphometry, collagen fiber anisotropy, and biological apatite (BAp) crystallite alignment were quantitatively evaluated in both groups after extraction and fixation of the jaw bone at Days 7 and 21 after surgery.ResultsOsseointegration was observed in both groups. Bone morphometry showed significant differences in bone volume, trabecular number, trabecular thickness and bone mineral density (BMD) at Days 21 postoperatively (P < 0.05). A significant difference was also found in the trabecular separation at Days 7 postoperatively (P < 0.05). In the evaluation of collagen fiber anisotropy, collagen fiber bundles running differently from the existing bone were observed in both groups. In terms of BAp crystallite alignment, a specific structure was observed in the reconstructed new bone after implantation, and preferential orientation of BAp crystallite alignment was observed in the longitudinal direction of the implants in the Day 21 postoperative loaded group.ConclusionWhen sufficient initial fixation is achieved at the time of dental implant placement, then the applied masticatory load may contribute to rapidly achieving not only bone volume, but also adequate bone quality after implant placement.