Flexural strength and degree of conversion of universal single shade resin-based composites.

Background/purpose: Recently, a group of universal single-shade resin-based composites (RBCs) has been developed to simplify the process of shade selection. Excellent mechanical and physical properties are crucial for the ultimate success and clinical longevity of restorations. Therefore, evaluating the properties of the single-shaded RBCs is imperative. This study aimed to determine the flexural strength (FS) and degree of conversion (DC) of universal single-shade RBCs. Materials and methods: In this study, four commercial RBCs were used; three universal single-shade RBCs; Omnichroma (OC), Charisma® Diamond ONE (CD), and Vittra APS Unique (VU), and a conventional nanohybrid composite Filtek™ Z250 XT (FT) which was used as a control. Sixty composite beams and 40 composite discs were used for FS and DC, respectively. A universal test machine with a three-point bending test was used to measure the FS, whereas the DC was measured using a Fourier-transform infrared spectrometer (FTIR). Three fractured specimens from each resin composite group were qualitatively analyzed using scanning electron microscopy. Results: ANOVA was used to compare the mean values of FS and DC among the four RBCs (OC, CD, VU, and FT). Highly significant differences were observed in the mean FS and DC values (F = 673.043, p < 0.001 and F (=782.4, p < 0.0001), respectively. The highest FS was observed in the CD group, followed by FT and VU groups; the lowest value was observed in the OC group. In addition, a statistically significant difference was identified in DC values. The highest DC value was observed in VU, followed by OC and CD, and the lowest DC value was observed in FT. Conclusion: Universal single-shade RBCs demonstrated a good FS, except for OC, which exhibited a significantly low FS. The DC of the universal single-shade RBCs was higher than that of the conventional nanohybrid composite restorative material.

Comparison of Fracture Behavior in Single-Edge Notched Beams Reinforced with Steel Bars or CFRP Bars.

To explore and compare the failure modes, deformation behaviors, and load-bearing capacities of single-edge notched (SEN) beams strengthened with carbon fiber-reinforced polymer (CFRP) and steel bars, static and dynamic three-point bending tests on both types of concrete beams have been carried out in this study. During the static tests, the electro-hydraulic servo machine served as a loading device to apply pressure to CFRP beams and reinforced concrete (RC) beams. During the impact experiments, different impact velocities were imparted by adjusting the drop hammer's height. Thus, information regarding crack propagation, energy absorption, and deformation was obtained. The results from the static tests showed that the RC beams predominantly experienced shear failure. In contrast, the CFRP beams primarily exhibited bending-shear failure, attributed to the relatively weaker bond strength between the bars and the concrete. Impact tests were conducted at three different velocities in this study. As the impact velocity increased, both types of concrete beams transitioned from bending failure to bending-shear failure. At the lowest velocity, the difference in energy absorption between beams reinforced with different materials was insignificant during the bending process. However, at the highest velocity, CFRP beams absorbed less energy than RC beams. The study of structures' impact failure modes and their mechanical characteristics offers valuable references for the anti-collision design and protection of structures.

The effect of moisture content over the fibre saturation points on the impact strength of wood.

The article's main aim is to assess the mechanical behaviour of linden under high-rate loadings (impact) and its change due to changes in moisture content (MC) over fibre saturation point. For assessing the mechanical properties of green wood, mainly the data of the dried wood is not applicable since the moisture content can drastically affect the mechanical properties of the wood. By testing both dried and high-moisture-content wood, we can understand a general viewpoint toward the effect of the moisture content on the impact behaviour of the wood. Several test samples were made of linden wood with different moisture content levels of 11%, 60% and 160%. A drop-weight impact machine tested the specimens to measure the reaction force of the hammer during a very short impact period. The results of the tests were parameters such as force-time chart, the maximum force required for crack initiation, the impact bending strength (IBS) and the work needed for crack initiation. The results indicated an increase in MC decreases the maximum force, work required for crack initiation and IBS drastically. However, when MC exceeded the fibre saturation point (FSP), there was no further influence on the force pattern and maximum required force.

Study on the Compressive and Flexural Properties of Coconut Fiber Magnesium Phosphate Cement Curing at Different Low Temperatures.

The incorporation of coconut fiber (CF) into magnesium phosphate cement (MPC) can effectively improve upon its high brittleness and ease of cracking. In practical engineering, coconut fiber-reinforced magnesium phosphate cement (CF-MPC) will likely work in cold environments. Therefore, it is essential to understand the effects of various types of low-temperature curing on CF-MPC performances, but there are very few studies in this area. In this study, the static compression and three-point bending test were utilized to examine the compressive and flexural characteristics of CF-MPC with various CF contents and different negative curing temperatures. Scanning electron microscopy (SEM) and X-ray diffraction (XRD) were conducted to observe the impact of low-temperature maintenance on the structure and hydration reaction of the specimens. The results indicate that CF-MPC curing at low temperatures was more prone to cracks during compression and bending, while the appropriate amount of CF could enhance its plastic deformation capability. The CF-MPC's compressive and flexural strength declined as the curing temperature dropped. Moreover, with the rise in CF content, the samples' compressive strength also tended to fall, and there was a critical point for the change in flexural strength. In addition, MPC's primary hydration product (MgKPO4·6H2O) decreased with a drop in curing temperature, and more holes and fractures appeared in CF-MPC.

Effect of Core Density on the Three-Point Bending Performance of Aluminum Foam Sandwich Panels.

Using the powder-metallurgy rolling method, aluminum foam sandwich (AFS) panels with a metallurgical bond between the foam core and the panel can be produced. In this study, by manipulating the foaming temperature and duration, AFS panels were fabricated with varying core densities and thicknesses, all maintaining a panel thickness close to 1 mm. Through the three-point bending test, this research deeply delved into how core density influences the mechanical behaviors of these AFS panels. It became evident that a rise in core density positively affects the bending strength and failure load of the panels but inversely impacts their total energy absorption efficiency. Differing core densities brought about distinct failure patterns: low-density samples primarily showed panel indentation and core shear failures, whereas those of high density demonstrated panel yield and fractures. Furthermore, the research offers predictions on the initial failure loads for different failure modes and introduces a comprehensively designed failure diagram, laying a foundational theory for the production of AFS panels.

Biomechanical Effects of Angiotensin 1-7 in Diabetes Rats Femur / Efectos Biomecánicos de la Angiotensina 1-7 en el Fémur de Ratas Diabéticas

SUMMARY: It is known that diabetes mellitus has late complications, including microvascular and macrovascular diseases. Diabetes can affect bones through biochemical markers of bone structure, density, and turnover. This study aimed to biomechanically investigate the bone-protective effects of angiotensin 1-7 (Ang 1-7), one of the active peptides in the renin-angiotensin system, in rats with diabetes. Thirty male Wistar albino rats, three months old and weighing 250-300 g, were divided into four groups: diabetes, Ang 1- 7, diabetes plus Ang 1-7, and control. One month later, diabetes developed in rats; the rats were sacrificed, and their right femur was removed. Three-point bending biomechanical tests were performed on the femurs. The diabetic group had significantly higher bone fragility than the other groups (Pr >.05). Bone fragility was lower, and bone flexibility was higher in the Ang 1-7 groups (Pr>F value 0.05). As a result of our study, the effect of Ang 1-7 on the bones of rats with diabetes was investigated biomechanically. Ang 1-7 has a protective impact on the bones of rats with diabetes.

Se sabe que la diabetes mellitus tiene complicaciones tardías, incluyendo enfermedades microvasculares y macrovasculares. La diabetes puede afectar los huesos a través de los marcadores bioquímicos de la estructura, la densidad y el recambio óseo. Este estudio tuvo como objetivo investigar biomecánicamente los efectos protectores en los huesos de la angiotensina 1-7 (Ang 1-7), uno de los péptidos activos en el sistema renina-angiotensina, en ratas con diabetes. Treinta ratas albinas Wistar macho, de tres meses de edad y con un peso de 250-300 g, se dividieron en cuatro grupos: diabetes, Ang 1-7, diabetes más Ang 1-7 y control. Un mes después, se desarrolló diabetes en ratas; se sacrificaron los animales y se extrajo su fémur derecho. Se realizaron pruebas biomecánicas de flexión de tres puntos en los fémures. El grupo diabéticos tenía una fragilidad ósea significativamente mayor que los otros grupos (Pr > 0,05). La fragilidad ósea fue menor y la flexibilidad ósea fue mayor en los grupos Ang 1-7 (valor Pr>F 0,05). Como resultado de nuestro estudio, se determinó biomecánicamente el efecto de Ang 1-7 en los huesos de ratas con diabetes. Se concluye que Ang 1-7 tiene un impacto protector en los huesos de ratas diabéticas.

Comparative in vitro study on biomechanical behavior of zirconia and polyetheretherketone biomaterials exposed to experimental loading conditions in a prototypal simulator.

Zirconia and polyetheretherketone (PEEK) are two biomaterials widely investigated as substitute for metals in oral prosthetic rehabilitation. To achieve a proper biomechanical behavior, the prosthetic biomaterials must ensure a good resistance to loads, as this is a crucial characteristic enabling their use in dental applications. The aim of this study was to investigate differences in the fracture resistance of different biomaterials in an experimental environment: fixed partial dentures (FPDs) screwed in a prototype of biomimetic mandible. 10 Samples of FPDs were allocated in 2 groups (A and B): Group A (n=5) involved FPDs in zirconia-ceramic, and Group B (n=5) involved FPDs in PEEK-composite. The samples were loaded by means of a three-point bending mechanical test, and the load to fracture has been evaluated generating a point-by-point graphics (speed/load and time/deformation). The samples were further analyzed by micro-computed tomography (micro-CT) and described under experimental loading conditions. Zirconia-ceramic FDPs were the samples reporting the worst results, showing a lower value of vertical displacement with respect to PEEK-based samples. The micro-CT results have further confirmed the preliminary results previously described. This in vitro study aims to give analytic data on the reliability of PEEK as a reliable and strong biomaterial for prosthetic treatments.

Effect of Particle Sizes and Contents of Surface Pre-Reacted Glass Ionomer Filler on Mechanical Properties of Auto-Polymerizing Resin.

Herein, the mechanical properties of an auto-polymerizing resin incorporated with a surface pre-reacted glass ionomer (S-PRG) filler were evaluated. For this, S-PRG fillers with particle sizes of 1 µm (S-PRG-1) and 3 µm (S-PRG-3) were mixed at 10, 20, 30, and 40 wt% to prepare experimental resin powders. The powders and a liquid (powder/liquid ratio = 1.0 g/0.5 mL) were kneaded and filled into a silicone mold to obtain rectangular specimens. The flexural strength and modulus (n = 12) were recorded via a three-point bending test. The flexural strengths of S-PRG-1 at 10 wt% (62.14 MPa) and S-PRG-3 at 10 and 20 wt% (68.68 and 62.70 MPa, respectively) were adequate (>60 MPa). The flexural modulus of the S-PRG-3-containing specimen was significantly higher than that of the S-PRG-1-containing specimen. Scanning electron microscopy observations of the specimen fracture surfaces after bending revealed that the S-PRG fillers were tightly embedded and scattered in the resin matrix. The Vickers hardness increased with an increasing filler content and size. The Vickers hardness of S-PRG-3 (14.86-15.48 HV) was higher than that of S-PRG-1 (13.48-14.97 HV). Thus, the particle size and content of the S-PRG filler affect the mechanical properties of the experimental auto-polymerizing resin.

Experimental and Hybrid FEM/Peridynamic Study on the Fracture of Ultra-High-Performance Concretes Reinforced by Different Volume Fractions of Polyvinyl Alcohol Fibers.

In this study, a series of three-point bending tests were carried out with notched beam structures made of polyvinyl alcohol (PVA) fiber-reinforced ultra-high-performance concrete (UHPC) to study the effect of volume fractions of PVA fibers on the fracture characteristics of the UHPC-PVAs. Furthermore, in order to meet the increasing demand for time- and cost-saving design methods related to research and design experimentation for the UHPC structures, a relevant hybrid finite element and extended bond-based peridynamic numerical modeling approach is proposed to numerically analyze the fracture behaviors of the UHPC-PVA structures in 3D. In the proposed method, the random distribution of the fibers is considered according to their corresponding volume fractions. The predicted peak values of the applied force agree well with the experimental results, which validates the effectiveness and accuracy of the present method. Both the experimental and numerical results indicate that, increasing the PVA fiber volume fraction, the strength of the produced UHPC-PVAs will increase approximately linearly.

In Silico Finite Element Analysis of Implant-Supported CAD-CAM Resin Composite Crowns.

PURPOSE: The aim of this study was to evaluate the mechanical behavior of an implant-supported crown made using computer-aided design and computer-aided manufacturing (CAD-CAM) resin composite (RC) blocks in the posterior region. MATERIAL AND METHODS: Four commercially available CAD-CAM RC blocks were used in this study: Cerasmart 300 (CS300; GC, Tokyo, Japan), Katana Avencia P Block (KAP; Kuraray Noritake Dental, Niigata, Japan); KZR HR3 Gamma Theta (HR3; Yamakin, Osaka, Japan), and Estelite P block (ESP; Tokuyama Dental, Tokyo, Japan). Katana Zirconia STML (ST; Kuraray Noritake Dental) was used as the control group. The elastic moduli of each material were determined by a three-point bending test. After the CAD models were designed, two different loading scenarios (oblique, vertical) were created. 3D finite element analysis was conducted with the prepared models. RESULTS: The elastic modulus of the material utilized for the implant restorations did not cause any change in the stresses transmitted to the implant or peripheral bone. An important difference was detected in the abutment-crown junction area. The minimum von Mises value at the abutment-crown interface was obtained in ST, which has the closest elastic modulus to the titanium abutment. CONCLUSIONS: The 3D finite element model designed in this study was used to demonstrate that implant-supported crowns fabricated with four different CAD-CAM RCs showed no critical stress concentrations in the bone or implant under all loading conditions. These results suggest that CAD-CAM RC blocks could be used as an alternative material for implant-supported restorations in the posterior region in terms of stress distribution.

Mechanical and numerical investigations of biodegradable magnesium alloy screws for fracture treatment.

Small fracture treatment includes the use of so-called "Herbert screws". In the past years, novel resorbable materials were introduced as an alternative to the classical titanium implants. The purpose of this study was to evaluate the influence of ongoing resorption/corrosion processes on the mechanical stability screws made from the magnesium alloy MgYREZr®. Our samples consisted of two partly resorbed screws, explanted due to medical reasons after 6 and 12 weeks, respectively, and five unused reference screws. We performed three-point bending tests to determine the stability of all screws. Additionally, with FE-models of the screws based on µCT-scans, we investigated whether any differences in the bending behavior of the screws can be attributed to the reduction of the material volume due to resorption alone. Both partly resorbed screws failed at a lower force than the reference screws (178.6 ± 5.5 N for the reference screws, 72.5 N and 74.5 N for the screw explanted after 6 and 12 weeks, respectively). FE simulations performed with the three different geometries and original material parameters (Young's modulus Enew  = 45 GPa, yield limit σnew  = 235 MPa) showed that the early fracture could not be attributed to the changed geometry alone. Material parameters for the partly resorbed screws were determined by fitting the numerical to the experimental force-displacement curves (E6week  = 15 GPa, σ6week  = 135 MPa and E12week  = 8 GPa, σ12week  = 135 MPa, respectively). Our results showed that both geometry of the screws and different material properties contribute to the overall stability. Understanding and controlling these two factors throughout the resorption process could enhance treatment options.

Bending Study of Six Biological Models for Design of High Strength and Tough Structures.

High strength and tough structures are beneficial to increasing engineering components service span. Nonetheless, improving structure strength and, simultaneously, toughness is difficult, since these two properties are generally mutually exclusive. Biological organisms exhibit both excellent strength and toughness. Using bionic structures from these biological organisms can be solutions for improving these properties of engineering components. To effectively apply biological models to design biomimetic structures, this paper analyses strengthening and toughening mechanisms of six fundamentally biological models obtained from biological organisms. Numerical models of three-point bending test are established to predict crack propagation behaviors of the six biological models. Furthermore, the strength and toughness of six biomimetic composites are experimentally evaluated. It is identified that the helical model possesses the highest toughness and satisfying strength. This work provides more detailed evidence for engineers to designate bionic models to the design of biomimetic composites with high strength and toughness.

Fracture Behavior and Digital Image Analysis of GFRP Reinforced Concrete Notched Beams.

This study presents three-point bending fracture tests on glass fiber-reinforced polymer (GFRP) reinforced concrete notched beams. Few studies have been conducted to date to understand the fracture behavior of this type of specimens. The specimens have nominal depth, width, and length equal to 150 mm, 150 mm, and 550 mm. Plain concrete notched beams with the same dimensions are cast from the same batch of concrete to compare the responses with GFRP reinforced concrete notched beams. The notch of the plain concrete specimens is either saw cut or cast. These two notch fabrication methods are compared based on the load responses. The peak load, crack mouth opening displacement (CMOD), GFRP bar slip at two ends, and load point displacement are used to discuss the results of the fracture tests. In addition, digital image analysis is performed to identify the fracture process zone (FPZ) and the location of the neutral axis, which are used to determine the force in the GFRP bar via cross-sectional analysis. Finally, the GFRP bar force versus slip responses are compared with those from the pull-out tests performed on the same bar to show that the bond of the bar in the pull-out tests represents an upper bound limit compared to the behavior in bending.

Microstructure, Shrinkage, and Mechanical Properties of Concrete with Fibers and Experiments of Reinforced Concrete Beams without Shear Reinforcement.

The current findings on concrete with fibers show that research has focused primarily on individual aspects, especially in terms of mechanical properties and structural uses. However, no broader view of the problems solved has been provided. In this study, we present a conceptual overview of a new, comprehensive experimental program for the assessment of fiber-reinforced concrete, which includes the analysis of microstructural and structural elements, as well as specific features such as shrinkage and resistance to pressurized water. The proposed experimental program included several variants of schemes for the dosing of fibers into concrete, using steel fibers that were short and straight. Fiber dosing was performed up to 110 kg/m3. The basic tests performed included tests of the compressive strength of concrete, and of the split and flexural tensile strength for different dosing amounts. Within the structural tests of reinforced concrete beams without shear reinforcement, two variants of spans with different degrees of reinforcement were implemented. Herein, the test results are evaluated graphically with a detailed analysis of the positive effect of fibers, and we also provide general recommendations for the structural uses of the fibers used and the design of fiber-reinforced concrete structures. Among the important results of this experimental program was the observation of a significant increase (of the order of tens) of the percentage of the split tensile strength and an increase of the overall load-bearing capacity of the reinforced concrete beams without shear reinforcement. Among the important aspects of our findings is the fact that a fine-grained concrete mixture was used, which increased resistance to pressure water seepage, and therefore, the effect of shrinkage can be influenced by the method of production and the treatment of the concrete used. We also provide detailed figures of the microstructure.

Mechanical Strength of Triply Periodic Minimal Surface Lattices Subjected to Three-Point Bending.

Sandwich panel structures (SPSs) with lattice cores can considerably lower material consumption while simultaneously maintaining adequate mechanical properties. Compared with extruded lattice types, triply periodic minimal surface (TPMS) lattices have light weight but better controllable mechanical properties. In this study, the different types of TPMS lattices inside an SPS were analysed comprehensively. Each SPS comprised two face sheets and a core filled with 20×5×1 TPMS lattices. The types of TPMS lattices considered included the Schwarz primitive (SP), Scherk's surface type 2 (S2), Schoen I-graph-wrapped package (I-WP), and Schoen face-centred cubic rhombic dodecahedron (F-RD). The finite element method was applied to determine the mechanical performance of different TPMS lattices at different relative densities inside the SPS under a three-point bending test, and the results were compared with the values calculated from analytical equations. The results showed a difference of less than 21% between the analytical and numerical results for the deformation. SP had the smallest deformation among the TPMS lattices, and F-RD can withstand the highest allowable load. Different failure modes were proposed to predict potential failure mechanisms. The results indicated that the mechanical performances of the TPMS lattices were mainly influenced by the lattice geometry and relative density.

Fracture Toughness of Moldable Low-Temperature Carbonized Elastomer-Based Composites Filled with Shungite and Short Carbon Fibers.

This work evaluated the fracture toughness of the low-temperature carbonized elastomer-based composites filled with shungite and short carbon fibers. The effects of the carbonization temperature and filler content on the critical stress intensity factor (K1c) were examined. The K1c parameter was obtained using three-point bending tests for specimens with different l/b ratio (notch depth to sample thickness) ranging from 0.2 to 0.4. Reliable detection of the initiation and propagation of cracks was achieved using an acoustic sensor was attached to the samples during the bending test. The critical stress intensity factor was found to decrease linearly with increasing carbonization temperature. As the temperature increased from 280 to 380 °C, the K1c parameter was drastically reduced from about 5 to 1 MPa·m1/2 and was associated with intense outgassing during the carbonization step that resulted in sample porosity. The carbon fiber addition led to some incremental toughening; however, it reduced the statistical dispersion of the K1c values.

Optimization of Embedded Sensor Packaging Used in Rollpave Pavement Based on Test and Simulation.

Rollpave pavement, as a rollable prefabricated asphalt pavement technology, can effectively reduce the overall road closure time required for pavement construction and maintenance. Sensors can be integrated into Rollpave pavement, thereby avoiding sensor damage that may otherwise result from high temperatures and compactive forces during the rolling process, as well as pavement structural damage resulting from cutting and drilling. However, the embedment of sensors into Rollpave pavement still presents certain challenges, namely poor interfacial synergy between the embedded sensor and the asphalt mixture. To solve this problem, three-point bending tests and dynamic response FEM simulations were used to optimize the embedded sensor's packaging. The influence of sensor embedment on Rollpave pavement under different working conditions was analyzed. Results of these analyses show that low temperature and the epoxy resin negatively affect the bending performance of specimens, and that packaging with cylindrical shape, flat design, and consisting of a material with modulus similar to that of the asphalt mixture should be preferred. This study is conducive to improve the intellectual level and service life of road infrastructure.

Technological and Strength Aspects of Layers Made of Different Powders Laminated on a Polymer Matrix Composite Substrate.

This study presents a description of the new technology for producing external or internal layers made of different powders mixed with epoxy resin, which can perform various functions as a protection against impact, erosion, or elevated temperatures as well as provide interlayers during the manufacturing of a ceramic protective barrier by air plasma spraying (APS) on the PMC substrate made of carbon-epoxy. Six types of powders (copper, quartz sand, Al2O3, aluminum, crystalline silica, and microballoon) were used to manufacture (120 °C) different kinds of protective layers (PLs), perfectly joined with the PMCs, in one single autoclave process. The two-layered specimens (2 × 25 × 110 mm) were subjected to a three-point bending (3-PB) displacement-controlled deformation process to determine the critical values of deformations at which the PLs can work safely without being cracked or delaminated. The tests were performed up to the final failure, observing various damage and cracking phenomena. Finally, the numerical simulations were carried out using the representative volume element (RVE) model of the most efforted central parts of the samples to determine the effect of powder grain diameter and resin content on the elastic properties and damage growth of the newly proposed multifunctional PLs. The stress concentrations and damage processes, including cracking and delamination, were analyzed in the whole two-layered system. The best result, in terms of strength during 3-PB testing, was achieved with the PL made of aluminum powder.

Investigations on Flexural and Compressive Strengths of Mortar Dedicated to Clinker Units-Influence of Mixing Water Content and Curing Time.

The article presents laboratory tests on the impact of the mixing water content used in the preparation of fresh mortar on the flexural and compressive strength of one of the dry-mix mortars produced by a leading European producer and dedicated to bricklaying with clinker elements. The development of these parameters in relation to curing time was also analyzed. The mortar samples were prepared from a factory-made mortar mix using 4.0 L (the value recommended by the mortar manufacturer), 4.5 L, and 5 L of water per 25 kg bag of ready-made, pre-mixed dry mortar mix. All samples were tested in five series after 5, 9, 14, 21, and 28 days of sample curing. The results of these tests showed that the use of 6 and 18% more mixing water than recommended by the manufacturer (4.5 and 5 L per bag) adversely affected the basic mechanical parameters of the tested mortar. Moreover, it was found that the highest compressive strength values were obtained after 21 days of curing and not after 28 days as usual. It was also found that hardening time and higher than recommended water content adversely affected the bending strength of the mortar.

Bone Union Assessment with Computed Tomography (CT) and Statistical Associations with Mechanical or Histological Testing: A Systematic Review of Animal Studies.

Objective and accurate assessment of bone union after a fracture, arthrodesis, or osteotomy is relevant for scientific and clinical purposes. Bone union is most accurately imaged with computed tomography (CT), but no consensus exists about objective assessment of bone union from CT images. It is unclear which CT-generated parameters are most suitable for bone union assessment. The aim of this review of animal studies is to find which CT-generated parameters are associated most strongly with actual bone union. Scientific databases were systematically searched. Eligible studies were studies that (1) were animal studies, (2) created a fracture, (3) assessed bone union with CT, (4) performed mechanical or histological testing as measure of actual bone union, and (5) associated CT-generated outcomes to mechanical or histological testing results. Two authors selected eligible studies and performed risk of bias assessment with QUADAS-2 tool. From 2567 studies that were screened, thirteen studies were included. Most common CT parameters that were investigated were bone mineral density, bone volume, and total callus volume. Studies showed conflicting results concerning the associations of these parameters with actual bone union. CT-assessed torsional rigidity (assessed by three studies) and callus density (assessed by two studies) showed best results. The studies investigating these two parameters reported moderate to strong associations with actual bone union. CT-assessed torsional rigidity and callus density seem the most promising parameters to represent actual bone union after a fracture, arthrodesis, or osteotomy.Prospero trial registration number: CRD42020164733.