Bone Plate Research Articles

Effect of Salvadora persica chewing sticks on maxillary central incisors crown-root angulation in Western-Asian population & correlation with Collum angle on 3D CBCT images

The main aim of the study was to identify the Collum angle classification for maxillary central incisors among individuals use vs not-use chewing sticks which could have beneficial role for immediate implant placement in respective individuals. Additionally, to identify the root-crown positioning and angulation in the Western Asian Saudi Arabian population for chewing sticks user’s vs non-users in order to develop guideline for the prosthetic procedures using Cone beam computed tompography (CBCT). A total number of 380 CBCT scans were included in the study for both of the groups based on the inclusion criterion of the patients reporting to the Dental OPD of Riyadh Elm University. The data was analyzed using 3D planner dental imaging software. Initially the teeth were classified based on root position in relation to facial plate of alveolar bone using Jung et al. classification. Additionally, the Collum angle and the root angulation of the maxillary central incisors was evaluated. The data was analyzed using one-way Anova with post-hoc Tuckey-Kramer test for pair-wise comparison. As per the Jung et al. classification, majority of the roots were observed with buccal placement. Based on the Collum angle classification majority of the maxillary central incisors were observed with facial placement (n=170), specially subtype I (n=78). But the root angulation was observed to be independent of Collum angle. Thus, it can be concluded, unlike root angulation, Collum angle has a correlation with root positioning. The angle for the individuals using chewing sticks of Salvadora Persica was similar to the individuals not using the miswak. Collum angle is correlated in all classified position of root. But the root angulation is independent of classification varies between miswak and non-miswak users.

Review of osteoderm function and future research directions

AbstractOsteoderms, bone plates in the skin, are widely but discontinuously distributed across the phylogeny of tetrapods. This and their pronounced morphological disparity has inspired many hypotheses on possible osteoderm functions. Most of these have not been systematically studied or summarised based on the published disparate literature. We provide here a comprehensive overview of the current state of knowledge in this field with a focus on extant non‐avian reptiles. We also discuss functions in other extant osteoderm‐bearing taxa and those inferred from the fossil record. The hypotheses are categorised into protection, lifestyle and locomotion, physiology, and visual functions. A comprehensive overview of future directions in this field is provided. With this review, we hope to encourage future research to investigate the functional aspect of osteoderms. This might inspire biomimetics and shed light on the role that osteoderm expression may have played in shaping present‐day biodiversity.

Integrating machine learning for predicting biomechanical properties of layered manufactured bone implants

AbstractThe layered manufacturing (LM) based locking bone plates (LBPs) are highly favored for biomedical applications due to its implant customization flexibility, control over porosity, and functional parameters. Design of experiments mainly relies on predefined experimental run orders; however, machine learning (ML) can handle complex and nonlinear relationships for predicting output responses. This research investigates the application of various ML models for predicting the impact strength, torque values, and punch shear strength of poly lactic acid (PLA) based LBPs. A dataset of 100 data points for each response variable was developed, analyzing the influence of printing parameters, like infill density (ID), layer height (LH), wall thickness (WT), and print speed (PS). The ID, LH, WT, and PS were varied within the ranges of 20%–100%, 0.1–0.5 mm, 0.4–1.2 mm, and 20–100 mm/s, respectively. Among the ML models evaluated, XGBoost and Adaboost exhibited strong alignment of the predicted values with actual values. The decision tree regression, showed the lowest predictive accuracy due to its tendency to overfit and lack of iterative refinement. The findings suggest that ML models can effectively predict the mechanical properties of PLA‐based LBPs, offering valuable insights for optimizing printing parameters to enhance the performance of orthopedic implants. The findings can guide biomedical engineers in making data‐driven decisions to enhance the strength of LBPs, thereby improving patient outcomes in orthopedic treatments.Highlights Predicted impact strength, torque, and shear strength of biomedical specimens. Evaluated 100 data points per variable to assess printing parameters' influence. XGBoost and Adaboost showed superior accuracy, with R2 consistently above 0.9. Decision Tree regression exhibited the lowest accuracy due to overfitting issues. Aims to guide biomedical engineers in data‐driven decisions for better patient outcomes.

Plating after tumor curettage in human femora does not efficiently improve torsional stability ex vivo

BackgroundSurgical treatments of benign primary bone tumors of the femur face the challenge of limiting tissue damage and contamination while providing sufficient stabilization to avoid fracture. While no clear treatment guidelines exist, surgical treatment commonly consists of femoral fenestration and curettage with optional filling and plating of the defect. Mono- or bicortical plating of distal femoral defects aim to reduce fracture risk and have been shown to increase axial stability. However, it remains unclear whether plating increases torsional stability of the affected femur. Questions/purposesThis biomechanical study aimed to determine how much additional stability can be achieved by mono- or bicortical plating of femoral defects after fenestration. The following hypotheses were investigated: 1. Preventive plating of distal femur bone defects enhances torsional stability when compared to femoral fenestration alone. 2. A condition close to the intact (nonpathological) bone can be achieved by bone plating. 3. Defect shape influences torsional stability. Patients and methodsThiel embalmed human femora (n = 24) were left intact or subjected to the following surgical treatments (A) defect creation via fenestration, (B) defect with short monocortical plating, (C) defect with long bicortical plating. All femora were torsion tested in midstance position using pre-cycling and testing until failure. Quantitative computed tomography pre and post testing allowed bone mineral density calculation and crack path analysis. Finite element analysis provided insight into defect shape variations. ResultsTorsion experiments showed no relevant enhancement of torsional stability due to mono- or bicortical plating. There were no significant differences in maximum torque between unplated and plated femora with defect (defect: 35.38 ± 7.53 Nm, monocortical plating: 37.77 ± 9.82 Nm, bicortical plating: 50.27 ± 9.72 Nm, p > 0.05). Maximum torque for all treatment groups was significantly lower compared to intact femora (155–200 Nm, p < 0.001). Cracks originated predominantly from the proximal posterior corner of the defect and intersected with screw holes in plated femora. The influence of variations of the defect corner shapes had no significant influence on maximum torque and angle. ConclusionThis biomechanical study shows that mono- or bicortical plating is not an effective preventive treatment against torsional failure of femora with distal defects as the resulting maximum torque was drastically reduced compared to intact femora. Thus, the initial hypotheses have to be rejected. As habitual loading of the femur includes a combination of axial and torsional loading, the observed lack of prevention against torsional failure might help to explain the occurrence of fractures despite plating. Future research towards ameliorating clinical outcome should address the role of defect filling with bone cement or bone grafts regarding the improvement of torsional stability after primary bone tumor treatment in the femur.

Distribution of bone fragments in angled shots: an experimental study conducted on composite models containing artificial bone plates.

In conventional gunshot injuries to targets containing bone the resulting osseous fragments do not precede but follow the bullet on its further way through adjacent soft tissues. The term "secondary projectiles" for the particles does not appear to be appropriate since they are not believed to have enough energy necessary for creating their own wound channels away from the temporary cavity. Former studies have shown that in angled shots to glass panes the bulk of splinters does not follow the bullet's trajectory: The majority of the glass fragments, especially the larger ones, move at right angles to the pane shot through. The aim of the presented study was to examine whether osseous fragments behave like glass splinters in angled shots to flat synthetic bone. In this context, it should also be assessed, whether the bone fragments might act as secondary projectiles in rare cases. To answer these questions, test shots were fired to composite models consisting of flat synthetic bone and ballistic gelatin. Pistol cartridges 9mm Luger were used to fire the shots which were video-documented with a high-speed camera. Afterwards, the composite models underwent CT examination and macroscopic inspection. Video-documentation revealed that the larger bone particles from the perforation site move at a roughly right angle from the osseous sheet into the gelatin, causing an eccentric bulge of the temporary cavity. The smaller bone fragments were also lodged along the bullet's path, predominantly in the cracks radiating from the permanent wound channel.

Differential effects of alendronate on chondrocytes, cartilage matrix and subchondral bone structure in surgically induced osteoarthritis in mice

Bisphosphonates (BP) are considered a treatment option for osteoarthritis (OA) due to reduction of OA-induced microtrauma in the bone marrow, stabilization of subchondral bone (SB) layer and pain reduction. The effects of high-dose alendronate (ALN) treatment on SB and articular cartilage after destabilization of the medial meniscus (DMM) or Sham surgery of male C57Bl/6J mice were analyzed. We performed serum analysis; histology and immunohistochemistry to assess the severity of OA and a possible pain symptomatology. Subsequently, the ratio of bone volume to total volume (BV/TV), epiphyseal trabecular morphology and the bone mineral density (BMD) was analyzed by nanoCT. Serum analysis revealed a reduction of ADAMTS5 level. The histological evaluation displayed no protective effect of ALN-treatment on cartilage erosion. NanoCT-analysis of the medial epiphysis revealed an increase of BV/TV in ALN-treated mice. Only the DMM group had significantly higher SB volume accompanied by decreased subchondral bone surface. Furthermore Nano-CT analysis revealed an increase in trabecular density and number, a decreased BMD and reduced osteophyte formation in the ALN mice. ALN treatment affected bone micro-architecture by reducing osteophytosis with simultaneous increasing subchondral bone plate thickness, trabecular thickness and BMD. Accordingly, ALN cannot be considered as a potential treatment strategy in general, however in a subgroup of patients with high bone turnover in an early-stage of OA, ALN might be an option when applied during a restricted time frame.

The degenerated glenohumeral joint.

This study aimed to define the histopathology of degenerated humeral head cartilage and synovial inflammation of the glenohumeral joint in patients with omarthrosis (OmA) and cuff tear arthropathy (CTA). Additionally, the potential of immunohistochemical tissue biomarkers in reflecting the degeneration status of humeral head cartilage was evaluated. Specimens of the humeral head and synovial tissue from 12 patients with OmA, seven patients with CTA, and four body donors were processed histologically for examination using different histopathological scores. Osteochondral sections were immunohistochemically stained for collagen type I, collagen type II, collagen neoepitope C1,2C, collagen type X, and osteocalcin, prior to semiquantitative analysis. Matrix metalloproteinase (MMP)-1, MMP-3, and MMP-13 levels were analyzed in synovial fluid using enzyme-linked immunosorbent assay (ELISA). Cartilage degeneration of the humeral head was associated with the histological presentation of: 1) pannus overgrowing the cartilage surface; 2) pores in the subchondral bone plate; and 3) chondrocyte clusters in OmA patients. In contrast, hyperplasia of the synovial lining layer was revealed as a significant indicator of inflammatory processes predominantly in CTA. The abundancy of collagen I, collagen II, and the C1,2C neoepitope correlated significantly with the histopathological degeneration of humeral head cartilage. No evidence for differences in MMP levels between OmA and CTA patients was found. This study provides a comprehensive histological characterization of humeral cartilage and synovial tissue within the glenohumeral joint, both in normal and diseased states. It highlights synovitis and pannus formation as histopathological hallmarks of OmA and CTA, indicating their roles as drivers of joint inflammation and cartilage degradation, and as targets for therapeutic strategies such as rotator cuff reconstruction and synovectomy.

Diagnostic imaging findings in lame Warmblood horses with bone injuries of the medial proximal phalanx glenoid cavity.

This retrospective study aims to describe baseline and follow-up imaging findings in subchondral and trabecular bone damage occurring outside of the sagittal groove in the proximal phalanx (P1) glenoid in a case series of lame Warmblood horses. Thirteen lame horses (16 forelimbs) with standing magnetic resonance imaging (sMRI) evidence of nonsagittal groove glenoid subchondral and trabecular bone injury of P1 as the main lesion were included. All injuries were located at the medial aspect of the P1 glenoid. At sMRI, changes included subchondral bone plate thickening and trabecular sclerosis, bone marrow edema-like signal, subchondral bone resorption (11/16), and new bone production (8/16). Subchondral bone resorption in the transverse plane was linear (8/11), round (2/11), or ill-defined (1/11). Sclerosis, bone resorption, and new bone production were seen radiographically in 10, 4, and 5 limbs, respectively. All limbs had concurrent metacarpal condyle sMRI imaging abnormalities, osteophytosis, and joint effusion. Follow-up sMRIs were obtained in 8 of 16 limbs, five of which showing progression of the resorptive lesion. One horse encountered a comminuted fracture of the affected P1 18 months after the follow-up sMRI examination. The imaging appearance of the medial glenoid bone injuries of P1 in this case series is consistent with chronic bone overload. The linear configuration of bone resorption seen in eight lesions suggests short, incomplete stress fractures, which is supported by the ultimate catastrophic fracture occurring in one case.

Palatal root endodontic microsurgery in maxillary molars using the palatal approach: a case study

BackgroundIn clinical practice, the buccal approach is typically the primary choice for endodontic microsurgery. Owing to the thickness of the buccal bone plate, the distance between the buccal bone plate and palatal lesion location, and soft tissue traction, the palatal approach may be more suitable for microsurgery for apical periodontitis of the palatal roots of the maxillary molars. However, the length of the palatal root, location of the greater palatine artery (GPA) and foramen (GPF), and surgical field of observation make palatal surgery challenging.Case presentationWith the aid of Cone-beam computed tomography imaging, the palatal approach was successfully applied in nine cases of endodontic microsurgery of the palatal root of a maxillary molar with a periapical lesion in Hangzhou Stomatology Hospital from January to December 2022.ConclusionsComplete healing was assessed based on clinical symptoms and radiographic images at the 3- and 24-month follow-up visits in all nine cases. Several tips have been proposed including surgical positioning, incision design, palate flap modification, bone removal, and root-end resection.

Studies on surface roughness and axial thrust force of drilled holes in Mg-Zn-Ca bio-medical alloy

Mg-Zn-Ca alloy is a promising candidate for orthopaedic implants such as bone plates and screws, as it has a similar mechanical strength and elastic modulus to bone, and it degrades in the body without causing toxicity or inflammation. Drilling studies are necessary to optimize the drilling process parameters, to evaluate the machinability and surface integrity of Mg-Zn-Ca alloy, and to ensure the effective and efficient drilling for various applications in the medical and engineering fields. The present experimental study emphasizes the influence of Ca content, biofriendly coolants and their combined effect with standard drill bits on the surface quality and axial thrust force in the drilling operation of Mg-Zn-Ca alloy. The drilling parameters such as cutting speed, feed rate, standard tools, bio-compatible coolants were optimized with respect to the amount of Ca in the Mg-Zn alloy. The axial thrust force and average surface roughness of drilled holes were considered as response of the experiments. The drilled surfaces were measured for average surface roughness in the transverse direction along the centre path of the drilled hole and a qualitative analysis was also carried out using advanced confocal microscope. The results revealed that the cutting speed among continuous factors significantly influenced the axial thrust force and average surface roughness. The effect of categorical factors was assessed using a regression based ranking method. The results of statistical analysis revealed that high speed steel, and vegetable oil offered improved surface quality, whereas the coconut oil showed low axial thrust force. The liquid nitrogen showed high value of axial thrust force and average surface roughness due to the brittleness induced by cryogenic coolant before drilling operation.

Study on the forging process of artificial bone plates of SUS 316L

Abstract SUS 316L stainless steel, valued for its strength and biocompatibility, is a popular choice for artificial bone plates. Forged SUS 316L plates offer advantages like enhanced strength, improved fatigue resistance, reduced material waste, and increased production efficiency. Consequently, the forging technology and die design for SUS 316L is crucial in the manufacturing of high quality artificial bone plates. Finite element analysis simulates the forging process of SUS 316L bone plates, guiding the selection of the appropriate forging machine, die design, and process parameters based on the resulting forging load, stress distribution, and filling condition. Ultimately, this approach facilitates the creation of high-quality SUS 316L bone plates with precise dimensional accuracy.

Mineralization of equine proximal sesamoid bones precedes articular cartilage and fibrocartilaginous enthesis maturation in early postgestational development.

To describe the development and maturation of equine proximal sesamoid bones (PSBs) in fetuses and young horses using radiography, microcomputed (micro)-CT, and histology. A descriptive study. Forelimb PSBs from 12 equids ranging in age from 105 days of gestation to 540 days postgestation were evaluated. Radiography was used for preliminary assessment of metacarpophalangeal joint and PSB mineralization, and micro-CT imaging was performed to assess mineralized PSBs. Tissue volume, bone volume fraction, height, width, depth, trabecular thickness, and anisotropy were quantified from midplanar micro-CT sections in 3 dimensions. Midsagittal PSB histologic sections stained with H&E and Safranin O/Fast Green were used to determine the ratio of ossification center to cartilage template size and to describe the formation and development of the cartilage template, ossification center, spherical growth plate, articular cartilage, and entheses. Mineralization of equine PSBs is associated with cartilage canals and a spherical growth plate that undergoes endochondral ossification during the late gestation to early postgestational period. The apical, flexor, basilar, and articular ossification fronts demonstrate morphologic variability. Structural organization of the articular cartilage and entheses occurs concurrently with the development of an underlying plate of compact bone. At 540 days postgestation, the fibrocartilaginous entheses of the flexor cortex of the PSB had yet to mature. Equine PSBs mineralize predominantly by endochondral ossification during the late gestation to early postgestational period. Mineralization precedes maturation of the articular cartilage and fibrocartilaginous entheses. The postgestational maturation of the PSB and its surrounding tissues may predispose young horses to developing lesions at these sites, such as apical avulsion fractures, warranting further investigation.

Analysis of factors affecting bone volume changes after immediate implantation in the maxillary central incisor.

This study aimed to evaluate the clinical outcomes of immediate implantation of single maxillary central incisor and explore factors affecting post-implant bone volume. Clinical data and imaging records from pre-surgery, the day of surgery, and 6 months post-surgery of 100 patients (100 implants) with non-salvageable maxillary central incisors who underwent immediate implantation were collected. Bone thickness at the cervical, middle, and apical regions of the implant's labial and palatal sides were measured immediately post-surgery and at 6 months, and bone volume changes were observed. A regression analysis model was used to assess predictive factors for labial and palatal bone plate thickness. At 6 months post-surgery, the labial bone thicknesses at the cervical, middle, and apical regions were 2.35, 2.29, and 3.28 mm, respectively, and those of the palatal side were 0.00, 2.40, and 6.05 mm, respectively. The cervical region had the highest alveolar crest collapse rates, with 32.87% on the labial side and 62.20% on the palatal side. The regression model indicated that factors influencing the thickness of bone at the cervical labial side of the implant included initial bone thickness, the implant center to adjacent tooth center angle, implant diameter, and the type of implant closure (P<0.05). The initial bone thickness on the palatal side was the sole predictor for bone thickness on the palatal side (P<0.05). Immediate implantation of single maxillary central incisors yields effective clinical results. The thickness of new bone around the implant is influenced by multiple factors. A comprehensive consideration of these factors in the planning of immediate implantation is necessary to achieve optimal therapeutic outcomes.

Molybdenum nanodots act as antioxidants for photothermal therapy osteoarthritis

Osteoarthritis (OA) manifests as the degradation of cartilage and remodeling of subchondral bone. Restoring homeostasis within the joint is imperative for alleviating OA symptoms. Current interventions primarily target singular aspects, such as anti-aging, inflammation inhibition, free radical scavenging, and regeneration of cartilage and subchondral bone. Herein, we developed molybdenum nanodots (MNDs) as bionic photothermal nanomaterials to mimic the antioxidant synthase to concurrently protected cartilage and facilitate subchondral bone regeneration. With near-infrared (NIR) irradiation, MNDs effectively eliminate reactive oxygen and nitrogen species (ROS/RNS) from OA chondrocytes, thereby reversed mitochondrial dysfunction, mitigating chondrocyte senescence, and simultaneously suppresses inflammation, hence preserving the inherent homeostasis between cartilage matrix synthesis and degradation while circumventing safety concerns. RNA sequencing of OA chondrocytes treated with MNDs-NIR revealed the reinstatement of chondrocyte functionality, activation of antioxidant enzymes, anti-aging properties, and regulation of inflammation. NIR irradiation induces thermogenesis and synergistically promotes subchondral bone regeneration via MNDs, as validated through histological assessments and microcomputed tomography (Micro-CT) scans. MNDs-NIR effectively attenuate cellular senescence and inhibit inflammation in vivo, while also remodeling mitochondrial dynamics by upregulating fusion proteins and inhibiting fission proteins, thereby regulating the oxidative stress microenvironment. Additionally, MNDs-NIR exhibited remarkable therapeutic effects in alleviating articular cartilage degeneration in an OA mouse model, evidenced by a 1.67-fold reduction in subchondral bone plate thickness, an 88.57% decrease in OARSI score, a 5.52-fold reduction in MMP13 expression, and a 6.80-fold increase in Col II expression. This novel disease-modifying approach for OA utilizing MNDs-NIR offers insight and a paradigm for improving mitochondrial dysfunction by regulating the accumulation of mitochondrial ROS and ultimately alleviating cellular senescence. Moreover, the dual-pronged therapeutic approach of MNDs-NIR, which addresses both cartilage erosion and subchondral bone lesions in OA, represents a highly promising strategy for managing OA.

Osteochondritis Dissecans of the Medial Femoral Condyle: MRI Findings of Instability.

BACKGROUND: Osteochondritis dissecans (OCD) of the medial femoral condyle (MFC), a common cause of pediatric chronic knee pain, is often found to be stable at arthroscopy. OBJECTIVE: To investigate the performance of MRI for identifying instability of MFC OCD in children. METHODS: This retrospective study included 59 children (37 boys, 22 girls; mean age, 12.5±2.2 years) with 69 MFC OCD lesions, who underwent knee MRI from January 2016 to October 2023. Two radiologists independently reviewed examinations to determine regional findings (effusion, skeletal maturity, secondary physis visibility, progeny composition), as well as direct (osteochondral defect, intraarticular body, cartilage alteration, bone plate disruption, receded ossification front) and indirect (progeny-parent bone interface, radius of curvature, parent-bone low-signal intensity (SI) marginal rim, perilesional marrow edema) findings of instability; disagreements were resolved through consensus. Two investigators assessed an additional indirect finding, cyst(s), in consensus. Demographic characteristics, and lesion volume were collected. The reference standard for lesion stability was arthroscopy (n=52) or follow-up evaluation (based on symptoms and imaging findings) in patients managed conservatively (n=17). Stable and unstable lesions were compared. RESULTS: Forty-nine lesions were stable, and 20 were unstable. Sensitivity and specificity for instability, among features showing significant associations with instability, were 70.0% and 100.0% for skeletal maturity, 75.0% and 75.5% for osteochondral progeny composition, 100.0% and 85.7% for cartilage alteration, 85.0% and 81.6% for presence of progeny-parent bone interface, 30.0% and 100.0% for extensive interface, 90.0% and 34.7% for cyst(s), 45.0% and 91.8% for altered radius of curvature, 80.0% and 89.8% for parent-bone low-SI rim, and 50.0% and 81.6% for extensive perilesional marrow edema. In multivariable analysis, factors independently associated with instability included larger lesion volume and indirect signs (presence of interface, cyst(s), altered radius of curvature, parent-bone low-SI rim, and extensive perilesional marrow edema). Frequency of instability was 0.0%, 7.4%, 16.7%, 75.0%, 83.3%, and 100.0% for lesions with 0, 1, 2, 3, 4, and 5 indirect signs. CONCLUSION: Lesion instability was associated with an increasing number of indirect MRI signs. CLINICAL IMPACT: Assessment of lesion stability by MRI can help guide decisions between arthroscopy and conservative management for MFC OCD in children.

Biomechanical comparison of using traditional and 3D-printed titanium alloy anatomical assembly thin anterior plating under three patellar fracture conditions

ABSTRACT This study attempted to understand the biomechanics of using 3D-printed anatomical assembly thin bone plate (AATBP) and anterior star-shaped plating (ASP) under different patellar fractures. The transverse (C1), transverse plus second fragment (C2) and complex (C3) patella fractures were defined for performing the dynamic cyclic load test and finite element (FE) analysis. The AATBP was fixed onto the patella after adjusting the total fixation height using a ratchet mechanism and providing holding power hooks. The ASP contoured the plate/distal legs based on the patella surface curvature and generated an additional drill guide to avoid screw interference. The average ASP fixation fracture gaps were significantly larger than the AATBP fixation. FE analysis showed that the AATBP biomechanical performance was better than the ASP fixation for different patella fractures. The 3D-printed AATBP can be used effectively for different patella fractures without screw interference and demonstrated greater stability for comminuted patellar fractures.

A Review of the Development of Titanium-Based and Magnesium-Based Metallic Glasses in the Field of Biomedical Materials.

This article reviews the research and development focus of metallic glasses in the field of biomedical applications. Metallic glasses exhibit a short-range ordered and long-range disordered glassy structure at the microscopic level, devoid of structural defects such as dislocations and grain boundaries. Therefore, they possess advantages such as high strength, toughness, and corrosion resistance, combining characteristics of both metals and glasses. This novel alloy system has found applications in the field of biomedical materials due to its excellent comprehensive performance. This review discusses the applications of Ti-based bulk metallic glasses in load-bearing implants such as bone plates and screws for long-term implantation. On the other hand, Mg-based metallic glasses, owing to their degradability, are primarily used in degradable bone nails, plates, and vascular stents. However, metallic glasses as biomaterials still face certain challenges. The Young's modulus value of Ti-based metallic glasses is higher than that of human bones, leading to stress-shielding effects. Meanwhile, Mg-based metallic glasses degrade too quickly, resulting in the premature loss of mechanical properties and the formation of numerous bubbles, which hinder tissue healing. To address these issues, we propose the following development directions: (1) Introducing porous structures into titanium-based metallic glasses is an important research direction for reducing Young's modulus; (2) To enhance the bioactivity of implant material surfaces, the surface modification of titanium-based metallic glasses is essential. (3) Developing antibacterial coatings and incorporating antibacterial metal elements into the alloys is essential to maintain the long-term effective antibacterial properties of metallic biomaterials. (4) Corrosion resistance must be further improved through the preparation of composite materials, while ensuring biocompatibility and safety, to achieve controllable degradation rates and degradation modes.

Immediate Implantation with Autologous Mineralized Dentin Graft versus Deproteinized Bovine Bone as Space-Filling Substitute in Maxillary Anterior Zone: Retrospective Radiological and Clinical Study.

Background/Objectives: Various bone substitutes have been recommended to augment the horizontal gap following immediate implantation. The purpose of this study was to compare the effectiveness of an autogenous mineralized dentin graft or a deproteinized bovine bone in horizontal gap augmentation following immediate implant placement in the maxillary anterior region. Methods: A total of 110 patients underwent tooth extraction followed by immediate implant placement. The patients were divided into two groups. The first group received an autogenous mineralized dentin graft (the test group) while the second group received a deproteinized bovine bone (the control group) to augment the horizontal gap. Preoperative (T0), immediate postoperative (T1), and 1-year postoperative (T2) cone beam computed tomography scans were taken from all the patients. Linear measurements were recorded 1 mm (R1) and 5 mm (R2) points apical to the implant platform at both T1 and T2 time intervals. Pink Esthetic Scores and prosthetic complications were evaluated as well. Results: There were 57 patients with a mean age of 45.42 ± 9.86 (range 24-63 years) selected as the test group and 53 patients with a mean age of 40.28 ± 11.69 (range 20-63 years) as the control group. The mean reduction in the buccal bone plate at R1 was 6.39 ± 3.78% in the test group and 6.99 ± 5.01% in the control group (p > 0.05). The mean reduction in the buccal bone plate at R2 was 5.46 ± 4.98% in the test group and 6.77 ± 7.60% in the control group (p < 0.05). The PES and prosthetic-related complications were shown to be negligible between the groups (p > 0.05). Conclusions: The efficiency of using an autogenous mineralized dentin graft for horizontal gap augmentation showed similar results in comparison to using a deproteinized bovine bone in relation to buccolingual socket reduction following immediate implantation.

Material Homogenization of Human Femur Bone Material Using a New Weighted Approach

Abstract The design of efficient and safe biocompatible artificial implants for bone replacement and reconstructions requires a thorough understanding of natural bone material. A new homogenization approach is therefore used to predict effective material properties of the human femur bone. The bone structure is idealized as a functionally graded composite made of different quantities of a collagen protein matrix reinforced by hydroxyapatite mineral acting as the filler. Two distinct composite models were investigated, one where the mineral reinforcements were assumed to be randomly dispersed inclusions in a matrix of collagen, and a second model wherein the minerals were assumed to be unidirectional fibers. Predicted results for longitudinal and transverse elastic modulus from the models compare very well with range of values from published experimental data. It is also compared to those predicted using classical homogenization models. These material properties are then used to obtain the structural response of a bone plate section under transverse load.

The Use of Autogenous Rib Graft in Craniofacial Reconstruction: Case Series Study

Background: Hard tissue defects in the maxillofacial region due to trauma or ablative surgery result in functional and cosmetic problems. The method of choice in the treatment of facial defects is autogenous bone grafts. Objectives: To evaluate the use of rib grafts in the reconstruction of craniofacial deformities. Methods: This prospective study was presented for the reconstruction of craniofacial deformity using a rib bone graft. These cases were collected from the Maxillofacial Surgery Unit from October 2011 to November 2020. The sample consisted of 16 patients (14 males and 2 females, with a mean age of 34 years). The patients were divided according to the site of the defect. In all cases, a single rib was harvested. The fifth rib was taken. Bone graft fixation by bone plate, direct screws, and transosseous wiring. The success of the bone grafting was assessed by clinical and radiological examination. Results: The overall success rate in this study was 87.5%, while we had bone graft resorption in two cases (12.5%) of mandibular reconstruction. Only one case experienced donor site complications, a pleural tear, which successfully underwent suturing and chest tube insertion. Conclusions: Free autogenous rib was successfully used to reconstruct defects in the maxillofacial regions. It gives the best result when minimum loading is needed. Stabilization of the graft by rigid internal fixation and good adaptation to the recipient site helped to minimize complications.