Particulate Bone Research Articles

Heterogeneous alkaline catalyst synthesized from local bovine bone wastes for transesterification of palm oil into biodiesel

Abstract Local bovine bone wastes, which are abundant in Aceh Province, have been successfully used as biomineral sources to produce heterogeneous catalysts that result in alkaline oxide. This study aimed to produce alkaline oxides by employing a high heat breakdown approach on local bovine bone particles at atmospheric pressure. The physicochemical analysis of the obtained inorganic particles revealed that the predominant component of those obtained inorganic oxide particles was calcium oxides (CaO). Furthermore, the produced alkaline oxide was employed as an alkali oxide catalyst for the transesterification of palm oil (RPDPO) with methanol, yielding methyl ester compounds, which are well recognized as a sustainable and green diesel energy source.

A comparative analysis of particulate bovine bone substitutes for oral regeneration: a narrative review.

Particulate bovine bone substitutes (BS) are commonly used in oral regeneration. However, more literature is needed focusing on comparative analyses among various particulate bovine BS. This study evaluates pre-clinical and clinical data of different particulate bovine BS in oral regeneration. A narrative review was conducted by screening the PubMed database Included in the review were pre-clinical and clinical studies until 2024 comparing a minimum of two distinct particulate bovine BS. In addition to examining general data concerning manufacturing and treatment processes, biological safety, physical and chemical characteristics, and graft resorption, particular emphasis was placed on assessing pre-clinical and clinical data related to ridge preservation, sinus floor elevation, peri-implant defects, and various forms of alveolar ridge augmentation utilizing particulate bovine BS. Various treatment temperatures ranging from 300 to 1,250°C and the employment of chemical cleaning steps were identified for the manufacturing process of particulate bovine BS deemed to possess biosecurity. A notable heterogeneity was observed in the physical and chemical characteristics of particulate bovine BS, with minimal or negligible graft resorption. Variations were evident in particle and pore sizes and the porosity of particulate bovine BS. Pre-clinical assessments noted a marginal inclination towards favorable outcomes for particulate bovine BS subjected to higher treatment temperatures. However, clinical data are insufficient. No distinctions were observed regarding ridge preservation, while slight advantages were noted for high-temperature treated particulate bovine BS in sinus floor elevation. Subtle variances in both pre-clinical and clinical outcomes were observed in across various particulate bovine BS. Due to inadequate data, numerous considerations related to diverse particulate bovine BS, including peri-implant defects, must be more conclusive. Additional clinical studies are imperative to address these knowledge gaps effectively.

Histomorphometric Evaluation of New Bone Formation, Dimensional Changes, and Residual Particles in Alveolar Ridge Preservation Techniques Using InterOss® Anorganic Cancellous Bone Graft: A Longitudinal Study

Background and Objective. Following tooth extraction, socket healing leads to bone remodeling, which generally results in significant local anatomical changes in the height and width of the residual alveolar ridge. This study aimed to compare dimensional changes through histological and histomorphometric evaluation of newly formed bone and residual graft particles. Materials and Methods. We worked on 14 single-root or premolar teeth with fused roots with an indication for the preservation of the alveolar ridge and the subsequent placement of a dental implant. The techniques performed in the study were the Bartee technique for the preservation of the alveolar crest in seven teeth that presented a good amount of the remaining bone tissue (minimum 4 mm in the apical–coronal direction) or that had a buccal or lingual/palatine wall defect (group A) and the Bio-Col alveolar preservation technique (group B), in seven teeth that presented an intact alveolus (four remaining walls). Xenograft was used in both groups. Results: Morphometric evaluation of group A (Bartee technique) and group B (Bio-Col technique) showed 11.48% and 13.24% of reabsorption in the vertical direction (p=0.482) and 21.95% and 20.55% in the horizontal direction, respectively (p=0.949). At 6 months of healing, the histomorphometric evaluation showed 31.10% new bone formation and 28.09% residual particles in group A, 13.24% new bone formation (p=0.744), and 20.55% residual particles for group B (p=0.302). There were no statistically significant differences in dimensional changes between both groups. Conclusions. The Bartee and Bio-Col alveolar ridge preservation technique combined with a xenograft provides dimensional stability, counteracting the physiological resorption process and ensuring the stability of the surrounding tissues. Therefore, both techniques represent a predictable option for dental implant placement at 6 months of healing.

Combination of a Synthetic Bioceramic Associated with a Polydioxanone-Based Membrane as an Alternative to Autogenous Bone Grafting.

The purpose of this study was to evaluate the repair process in rat calvaria filled with synthetic biphasic bioceramics (Plenum® Osshp-70:30, HA:βTCP) or autogenous bone, covered with a polydioxanone membrane (PDO). A total of 48 rats were divided into two groups (n = 24): particulate autogenous bone + Plenum® Guide (AUTOPT+PG) or Plenum® Osshp + Plenum® Guide (PO+PG). A defect was created in the calvaria, filled with the grafts, and covered with a PDO membrane, and euthanasia took place at 7, 30, and 60 days. Micro-CT showed no statistical difference between the groups, but there was an increase in bone volume (56.26%), the number of trabeculae (2.76 mm), and intersection surface (26.76 mm2) and a decrease in total porosity (43.79%) in the PO+PG group, as well as higher values for the daily mineral apposition rate (7.16 µm/day). Histometric analysis presented material replacement and increased bone formation at 30 days compared to 7 days in both groups. Immunostaining showed a similar pattern between the groups, with an increase in proteins related to bone remodeling and formation. In conclusion, Plenum® Osshp + Plenum® Guide showed similar and sometimes superior results when compared to autogenous bone, making it a competent option as a bone substitute.

Spoon-assisted autologous particulate bone graft harvesting technique

Particulate bone plays a crucial role in various oral and maxillofacial surgical procedures, including reconstruction, implantation, and craniofacial surgery. Autologous bone and deproteinized bovine bone xenografts are the two primary resources used for such procedures, with the former demonstrating superior cost-effectiveness and reduced comorbidity rates, particularly in cases involving donor zones. However, a significant challenge lies in acquiring uniformly sized autologous particulate bone specimens, with existing tools often yielding coarse particles at a high cost. Consequently, commercial bone xenograft solutions are frequently favored despite lower standards. This technical note introduces a novel technique for swiftly, safely, and efficiently obtaining autologous particulate bone specimens. The procedure involves the use of a motor handpiece fitted with a micro drill and surgical spoon to collect the bone particles. The continuous irrigation with saline maintains a clear surgical field during the milling process. The collected bone particles are then transferred to a metal capsule for further use. This technique offers a promising solution to the challenge of inconsistent particle size associated with harvesting using traditional methods, providing surgeons with a reliable and efficient method of obtaining autologous particulate bone samples.

Evaluation of Secondary Alveolar Bone Grafting for Unilateral Complete Cleft Alveolus: A Retrospective Cone Beam Computed Tomography-Based Study.

Background: In patients with cleft lip and palate (CLP), secondary alveolar bone grafting (SABG) with particulate cancellous bone marrow (PCBM) is recommended. Objective: To compare bone graft outcomes in patients with unilateral CLP, when SABG is completed before or after canine tooth eruption (ACE or BCE), as measured by cone beam computed tomography (CBCT). Methods: Patients were allocated into two cohorts, ACE and BCE. The outcomes were evaluated using CBCT, followed by univariate and multifactorial analyses. Results: A total of 468 patients (age 11.61 ± 4.03 years; male/female 288/180) were analyzed, including 282 in the BCE group (9.41 ± 1.59 years, 175/107) and 186 in the ACE group (14.95 ± 4.31 years, 113/73). Although 5-level assessment revealed no significant difference in clinical success rate (>4 points) between the BCE and ACE groups (53.90% vs. 47.85%, p = 0.20), BCE group showed significantly higher rate of bone bridges formation (73.05% vs. 62.90%, p = 0.02), which can be attributed to variations in orthodontic participation and follow-up time. Independent predictors of graft failure were wide cleft, severe oronasal fistula, no palatal bone wall, and insufficient PCBM filling (p < 0.01). Conclusions: SABG should be performed before canine eruption with more aggressive PCBM filling and oral fistula management.

Development of polymer/carbon nanotubes incorporated sustainable materials for manufacturing of autobrake pad

AbstractAlthough asbestos fiber is used for autobrake pad production due to its heat resistance capacity, it is associated with a challenge of health risk (cancerogenic in nature). This health risk associated with asbestos-based autobrake pads has presented polymeric materials as a better candidate for the application due to their eco-friendliness, lightweight, chemical inertness, easy of processing, etc. However, polymers are associated with low wear and low mechanical properties, which are vital properties for autobrake pads. Therefore, this study developed EP nanocomposites reinforced with a low content of carbon nanotubes (CNTs) and eggshell (ES) attached cow bone (CB) particles denoted as (ES@CB) as agro-waste/sustainable materials for the manufacturing of autobrake pads. The hybrid ternary nanocomposites were developed via solution mixing and casting. Scanning electron microscope (SEM) revealed the 1-D structure of the CNTs, and relatively spherical shapes of ES and CB particles, and microstructures of the developed nanocomposites. The nanocomposite showed a low coefficient of friction and a reduction in wear rate in the range of 1.14 × 10−4 mm3/Nm for pure EP to 5.45 × 10−6 mm3/Nm for EP/0.4wt%CNTs-10wt%ES@CB nanocomposite, while the elastic modulus and hardness increased from 1.84 GPa and 128.64 MPa for pure EP to 4.41 GPa and 252.88 MPa for EP/0.2wt%CNTs-20wt%ES@CB nanocomposite, respectively. The comparison of the wear response of the developed nanocomposites with the current asbestos-based brake pads show that the developed epoxy nanocomposites from agro-waste materials are potential option for the manufacturing of autobrake pads, which will ensure sustainability, health risk-free, and environmentally friendly.

Effect of Densah Burs on Primary and Secondary Stability of Immediately Loaded Implants in Addition to Crestal Bone Loss and Gingival Probing Depth - An Evaluative Study.

Osseodensification (OD) compaction increases primary stability by leaving the residual bone particles in the osteotomy site, which in turn act as an autograft. [ 1 ] Condensing the bone trabeculae through OD has demonstrated to have a potentiating influence on secondary stability. [ 2 ]. A split-mouth study was conducted in 40 patients to determine the effect of OD on implant success rate in terms of primary and secondary stability in situations including immediate loading of implants placed in low-density bone, which was tested using resonance frequency analysis (RFA) at the interval of 0, 6 th month. In order to assess the implant success rate, gingival probing depth and crestal bone loss (CBL) around the implant were also assessed at baseline and 6 months. With respect to primary stability, at baseline, the mean RFA of Densah burs is 71.6 ± 9.5 and of conventional drills is 67.6 ± 10.4. The mean stability of Densah burs is significantly higher than conventional drills, both at baseline and after 6 months as well. CBL, at baseline, the mean CBL of Densah burs is 0.58 ± 0.11 and of conventional drills is 0.64 ± 0.12. The mean CBL of Densah burs is significantly lower than that of conventional drills for both. The implant stability values found in the present study were remarkable when compared between OD and conventional osteotomy techniques. Decreased loss of bone at the crest probing depth also aided in the increased success rate.

Assessment of bone gain and neurosensory affection with the sandwich osteotomy technique for vertically deficient posterior mandible using a full digital workflow versus conventional protocol: A randomized split mouth study.

Using the sandwich osteotomy technique in the posterior mandible is delicate. This study aimed to assess the safety and the amount of bone gain using a full digital workflow versus the conventional procedure. This split mouth study included 10 patients with bilateral vertically deficient posterior mandible. One side received conventional sandwich interpositional bone grafting (control group), while the other side received the same protocol using two patient-specific guides. The first guide (cutting guide) was used to place the osteotomies safely and accurately according to the predetermined dimensions and locations, and the second guide was used to fix the mobilized bony segment, leaving the desired gap to be filled with a particulate xenogenic bone graft. Full neurosensory recovery was documented at 2 months postoperative for all patients and bilaterally. After 4 months, there was a statistically significant difference in vertical bone gain between both groups (p = 0.001), measuring an average of 3.76 ± 0.72 mm in the study group and 2.69 ± 0.37 mm in the control group. No statistically significant difference was found between the planned vertical augmentation (3.85 ± 0.58 mm) and the obtained vertical bone gain (3.76 ± 0.72 mm) in the study group (p = 0.765) proving the accuracy of the guided procedure. Computer-guided sandwich interpositional grafting is predictable regarding the execution of the osteotomies and the accuracy of fixation of the transport segment.

Clinical evaluation of bone quality of particulate cancellous bone and marrow, and implant prosthetic rehabilitation

This study aimed to subjectively evaluate bone quality in the particulate cancellous bone and marrow (PCBM) graft area and to assess the survival rates of implants.A retrospective review was conducted based on patient age, sex, diagnosis, reconstructed site, number of implants, prosthetic type, and duration of follow-up. Images from computed tomography (CT) before implant insertion were obtained and used in this study. We selected a 4.0-mm diameter × 8.0-mm length region of interest in the implant placement area, and measured the CT attenuation value.No significant correlations were seen between CT attenuation values and implant survival rates in the maxilla and mandible. On the other hand, CT attenuation values and implant survival rates were significantly lower in patients with malignancy than in non-malignant cases.Placing implants in PCBM grafted bone requires a full understanding of bone quality before surgery and drilling to ensure primary stability, along with consideration of soft tissue management and maintenance programs.

Three-dimensional printed silk fibroin and fenugreek based bio-composites scaffolds

When treating orthopaedic damage or illness and accidental fracture, bone grafting remains the gold standard of treatment. In cases where this approach doesn't seem achievable, bone tissue engineering can offer scaffolding as a substitute. Defective and fractured bone tissue is extracted and substituted with porous scaffold structures to aid in the process of tissue regeneration. Three-dimensional bioprinting has demonstrated enormous promise in recent years for producing scaffold structures with the necessary capabilities. In order to create composite biomaterial inks for three-dimensional bioprinting, four different materials were combined such as silk fibroin, bone particles (B), synthetic biopolymer poly (ε-caprolactone), and Fenugreek (F). These biomaterials were mixed together in certain proportion to develop a silk fibroin + bovine bone + polycaprolactone + fenugreek powder composites biomaterial which was later three-dimensional bioprinted to fabricated composite bio-scaffold. The biomechanical, structural, and biological elements of the manufactured composite scaffolds were characterized in order to determine their suitability as a possible biomaterial for the production of bone tissue. The in vitro bioactivity of the composite scaffolds was assessed in the simulated body fluids, and the swelling and degradation characteristics of the two developed scaffolds were analyzed separately over time. The results showed that the mechanical durability of the composite scaffolds was enhanced by the bovine bone particles, up to a specific concentration in the silk fibroin matrix. Furthermore, the incorporation of bone particles improved the bioactive composite scaffolds’ capacity to generate hydroxyapatite in vitro. The combined findings show that the three-dimensional printed bio-composites scaffolds have the required mechanical strength and may be applied to regeneration of bone tissue and restoration, since they resemble the characteristics of native bone.

3D bioprinting of mouse pre-osteoblasts and human MSCs using bioinks consisting of gelatin and decellularized bone particles

One of the key challenges in biofabrication applications is to obtain bioinks that provide a balance between printability, shape fidelity, cell viability, and tissue maturation. Decellularization methods allow the extraction of natural extracellular matrix, preserving tissue-specific matrix proteins. However, the critical challenge in bone decellularization is to preserve both organic (collagen, proteoglycans) and inorganic components (hydroxyapatite) to maintain the natural composition and functionality of bone. Besides, there is a need to investigate the effects of decellularized bone (DB) particles as a tissue-based additive in bioink formulation to develop functional bioinks. Here we evaluated the effect of incorporating DB particles of different sizes (≤45 and ≤100 μm) and concentrations (1%, 5%, 10% (wt %)) into bioink formulations containing gelatin (GEL) and pre-osteoblasts (MC3T3-E1) or human mesenchymal stem cells (hTERT-MSCs). In addition, we propose a minimalistic bioink formulation using GEL, DB particles and cells with an easy preparation process resulting in a high cell viability. The printability properties of the inks were evaluated. Additionally, rheological properties were determined with shear thinning and thixotropy tests. The bioprinted constructs were cultured for 28 days. The viability, proliferation, and osteogenic differentiation capacity of cells were evaluated using biochemical assays and fluorescence microscopy. The incorporation of DB particles enhanced cell proliferation and osteogenic differentiation capacity which might be due to the natural collagen and hydroxyapatite content of DB particles. Alkaline phosphatase activity is increased significantly by using DB particles, notably, without an osteogenic induction of the cells. Moreover, fluorescence images display pronounced cell-material interaction and cell attachment inside the constructs. With these promising results, the present minimalistic bioink formulation is envisioned as a potential candidate for bone tissue engineering as a clinically translatable material with straightforward preparation and high cell activity.

Optimal design of automatic generation control based on BBPSO-tuned PI for a restructured environment

ABSTRACT This paper intends to model an AGC regulator for a restructured environment using Bare Bone Particle Swarm Optimization (BBPSO). The gain-controlled Proportional–Integral (PI) Controller is designed here to enhance the performance of the BBPSO algorithm along with Gaussian distribution. The practical difficulty in handling the area control error to zero is the sudden variations in load. In practice, the tremendous contribution of deregulation in the power sector causes volatility in frequency and tie-line power deviations. To ensure the robustness of the proposed controller, three different cases of power system transactions have been considered. The performance has been validated by comparing it with Real Coded Genetic Algorithm-tuned PI controller (RCGA-PI) and Differential Evolutionary Algorithm-tuned PI controller (DE-PI) for the five area Thermal-Thermal generation test system. Moreover, the dynamic performance of an extensive range of demands and disturbances of all areas like settling time and overshoot against parametric precariousness has been done on the proposed test system.

Influence on marginal bone levels at implants equipped with blades aiming to control the lateral pressure on the cortical bone. An experimental study in dogs.

To avoid cortical compression, several implant systems have included in the protocol dedicated drills aimed at widening the cortical region of osteotomy. However, the manual execution of this operation does not guarantee the necessary precision. Hence, the present study aimed to determine the optimal size of the recipient site at the level of the alveolar crest in relation to the size of the coronal region of the implant to achieve the best healing result. Blades of different diameters were incorporated into the coronal part of the implant to prepare the cortical region of the mandibular alveolar bone crest in different dimensions in relation to the collar of the implant. The differences in diameter of the blades in relation to the collar of the implant were as follows: one control group, -175μm, and three test groups, 0μm, + 50μm, or + 200μm. The marginal bone loss (MBL) at the buccal aspect was 0.7mm, 0.5mm, 0.2mm, and 0.7mm in the - 175μm, 0.0μm, + 50μm, + 200μm groups, respectively. The differences were statistically significant between group + 50μm and control group - 175μm (p = 0.019), and between + 50μm and + 200μm (p < 0.01) groups. The level of osseointegration at the buccal aspect was more coronally located in the test groups than in the control group, whereas the bone-to-implant contact percentage was higher in the + 50μm and + 200μm groups. However, these differences were not statistically significant. The lowest bone crest resorption and highest levels of osseointegration were observed in the 0.0μm and + 50μm groups. The cortical region where the blades had performed their cutting action showed regular healing with perfect hard and soft tissues sealing in all the groups. Cortical blades gathered bone particles, particularly in the + 200μm group, which were incorporated into the newly formed bone. The results from the present experiment provide support to the use of blades that produce a marginal gap of 50μm after implant insertion.

Study on the Changes of Bone Calcium during the Fermentation of Bone Powders with Different Fermenters.

Two fermenters, Lactobacillus acidophilus (LA) and the active dry yellow wine yeast (HY), were utilized to ferment cattle bones in order to release calcium. The influences of fermenters and the fermentation process on the calcium release capacity, particle properties, morphology, and chemical composition of bone powders were assessed, and the underlying mechanism was discussed. The results showed that LA had a better capacity of acid production than yeast, and therefore released more calcium during the fermentation of bone powders. The released calcium in the fermentation broth mainly existed in the forms of free Ca2+ ions, organic acid-bound calcium and a small amount of calcium-peptide chelate. For bone powders, the fermentation induced swollen bone particles, increased particle size, and significant changes of the internal chemical structure. Therefore, fermentation has a great potential in the processing of bone-derived products, particularly to provide new ideas for the development of calcium supplement products.

In Vitro Handling Characteristics of a Particulate Bone Substitute for Ridge Preservation Procedures.

While particulate bone substitute materials are applied in a variety of augmentation procedures, standardized defects are being used for preclinical testing. This in vitro study evaluated the density and homogeneity of a particulate bone substitute in ridge preservation procedures. Premolars and molars were extracted in ten semimandibles of minipig cadavers. Light body impression material was used for determining the volume of the extraction sites followed by augmentation with particulate material, thereby weighing the graft material needed. Microradiographs and histologic sections were obtained for evaluating the homogeneity and density of the augmentation material. Statistical analyses were based on Shapiro-Wilk tests, Spearman's rho and one sample Wilcoxon test followed by Bonferroni-Holm correction for multiple testing (α = 0.05). Based on 103 single alveoli evaluated, the mean volume determined was 0.120 cm3 requiring a mean amount of graft material of 0.155 g. With only three exceptions, all parameters (volume, mass of augmentation material, density and homogeneity) correlated significantly (p < 0.020). The apical parts of the alveoli showed reduced density as compared to the middle parts (p < 0.001) and the homogeneity of the augmentation material was also lower as compared to the middle (p < 0.001) and cervical parts (p </= 0.040). The packing of augmentation material is critical when non-standardized defects are treated.

Development and Structural Evaluation of Dog Bone Particle–Reinforced Epoxy Composites for Biomedical Applications

There has been great interest in developing high‐performance, sustainable and eco‐friendly materials. This study presents an innovative development and research of the mechanical properties of dog bone–reinforced epoxy composites to determine their suitability for biomedical applications. Good surface compatibility for the matrix and reinforcement was the target, complementing the structural compatibility needed for such applications. Hand‐lay open mould technique was used to fabricate the composites with varying weight percentage of dog bone particles (DBPs), and mechanical properties (tensile strength, Young’s modulus, percentage elongation and flexural strength) were determined. The results show that the developed composites’ mechanical properties were enhanced, and the tensile strength of 21.10 MPa–27.97 MPa, Young’s modulus of 1531.00 MPa–1732.90 MPa, ductility of 2.10%–2.60% and flexural strength of 27.53 MPa–35.67 MPa were recorded for the biocomposites. Energy‐dispersive X‐ray spectroscopy (EDS) revealed the main elements’ contents of the DBPs as calcium (50.3%), carbon (20.77%) and oxygen (11.76%). Scanning electron microscopy (SEM) examination of the fractured surfaces revealed the homogeneous distribution of the dog bone particulates within the epoxy matrix, which caused the property enhancement. The findings of this research underline the potency of processed animal waste as filler materials.

In vitro and in vivo experiment of antibacterial silver nanoparticle-functionalized bone grafting replacements

Infection is a serious risk in transplant surgery and should be carefully considered while developing biomaterials. Silver nanoparticles (AgNPs) are gaining popularity due to their ability to enhance antibacterial capabilities against a wide range of bacterial types. This study sought to create two antibacterial bone regenerations by incorporating AgNPs into bovine bone particles (BBX) (Product 1) and a light cross-linked hydrogel GelMA (Product 2). Scanning electron microscopy was used to characterize the constructions. PrestoBlue™ was used to assess osteoblast and osteoclast metabolic activities on the creations. Optimized AgNP functionalized BBX and GelMA were tested in a rabbit cranial 6mm defect model to assess their regeneration ability. The presence of AgNPs appears to increase. In vitro, osteoblasts proliferated more than AgNP-free controls. It is found that a 100 μg dosage of AgNPs effectively suppresses bacteria while minimizing negative effects on bone cells. The rabbit model indicated that both BBX and GelMA hydrogels loaded with AgNPs were biocompatible, with no evidence of necrosis or inflammation. Grafts functionalized with AgNPs can defend against germs while also serving as a platform for bone cell adhesion.

The Effect of Cow Bone Particulate on the Mechanical Properties and the Microstructure of Aluminium Brass

This study investigates the mechanical properties and microstructural characteristics of aluminium brass composites reinforced with varying percentages of cow bone particulate (CBP). The analysis includes stress, strain, elongation at yield, Brinell hardness, and impact resistance measurements, complemented by microstructural examination. The results show that increasing CBP content enhances the stress capacity and hardness of the composites, with stress values rising from 2.2123 N/mm² at 0% CBP to 3.9951 N/mm² at 3% CBP, and Brinell hardness increasing from 52.98 BHN to 103.63 BHN. Conversely, strain values decrease from 16.8% to 13.26%, indicating a reduction in ductility. Impact resistance also diminishes with higher CBP content, from 43.52 joules at 0% CBP to 32 joules at 3% CBP. Microstructural analysis reveals that CBP particles are distributed both as clusters and fine isolated particles within the brass matrix, influencing grain size and boundary strength. These findings suggest that while CBP reinforcement enhances the hardness and stress resistance of aluminium brass, it also introduces brittleness, affecting the material’s overall ductility and impact resistance. The study provides valuable insights into the potential applications and limitations of CBP-reinforced aluminium brass composites.

Biomechanical Study of 3 Osteoconductive Materials Applied in Pedicle Augmentation and Revision for Osteoporotic Vertebrae: Allograft Bone Particles, Calcium Phosphate Cement, Demineralized Bone Matrix.

This study assessed biomechanical properties of pedicle screws enhanced or revised with 3 materials. We aimed to compare the efficacy of these materials in pedicle augmentation and revision. One hundred twenty human cadaveric vertebrae were utilized for in vitro testing. Vertebrae bone density was evaluated. Allograft bone particles (ABP), calcium phosphate cement (CPC), and demineralized bone matrix (DBM) were used to augment or revise pedicle screw. Post the implantation of pedicle screws, parameters such as insertional torque, pullout strength, cycles to failure and failure load were measured using specialized instruments. ABP, CPC, and DBM significantly enhanced biomechanical properties of the screws. CPC augmentation showed superior properties compared to ABP or DBM. ABP-augmented screws had higher cycles to failure and failure loads than DBM-augmented screws, with no difference in pullout strength. CPC-revised screws exhibited similar strength to the original screws, while ABP-revised screws showed comparable cycles to failure and failure loads but lower pullout strength. DBM-revised screws did not match the original screws' strength. ABP, CPC, and DBM effectively improve pedicle screw stability for pedicle augmentation. CPC demonstrated the highest efficacy, followed by ABP, while DBM was less effective. For pedicle revision, CPC is recommended as the primary choice, with ABP as an alternative. However, using DBM for pedicle revision is not recommended.