Bone Implants Research Articles

Design and Biofunctionalization of Cloud Sponge-Inspired Scaffolds for Enhanced Bone Cell Performance.

With the increasing age of our population, which is linked to a higher incidence of musculoskeletal diseases, there is a massive clinical need for bone implants. Porous scaffolds, usually offering a lower stiffness and allowing for the ingrowth of blood vessels and nerves, serve as an attractive alternative to conventional implants. Natural porous skeletons from marine sponges represent an array of evolutionarily optimized patterns, inspiring the design of biomaterials. In this study, cloud sponge-inspired scaffolds were designed and printed from a photocurable polymer, Clear Resin. These scaffolds were biofunctionalized by mussel-derived peptide MP-RGD, a recently developed peptide that contains a cyclic, bioactive RGD cell adhesion motif and catechol moieties, which provide the anchoring of the peptide to the surface. In in vitro cell culture assays with bone cells, significantly higher biocompatibility of three scaffolds, i.e., square, octagon, and hexagon cubes, in comparison to hollow and sphere inside cubes was shown. The performance of the cells regarding signaling was further enhanced by applying an MP-RGD coating. Consequently, these data demonstrate that both the structure of the scaffold and the coating contribute to the biocompatibility of the material. Three out of five MP-RGD-coated sponge-inspired scaffolds displayed superior biochemical properties and might guide material design for improved bone implants.

Three-Dimensional Semiconductor Network as Regulators of Energy Metabolism Drives Angiogenesis in Bone Regeneration.

Insufficient vascularization is a primary cause of bone implantation failure. The management of energy metabolism is crucial for the achievement of vascularized osseointegration. In light of the bone semiconductor property and the electric property of semiconductor heterojunctions, a three-dimensional semiconductor heterojunction network (3D-NTBH) implant has been devised with the objective of regulating cellular energy metabolism, thereby driving angiogenesis for bone regeneration. The three-dimensional heterojunction interfaces facilitate electron transfer and establish internal electric fields at the nanoscale interfaces. The 3D-NTBH was found to noticeably accelerate glycolysis in endothelial cells, thereby rapidly providing energy to support cellular metabolic activities and ultimately driving angiogenesis within the bone tissue. Molecular dynamic simulations have demonstrated that the 3D-NTBH facilitates the exposure of fibronectin's Arg-Gly-Asp peptide binding site, thereby regulating the glycolysis of endothelial cells. Further evidence suggests that 3D-NTBH promotes early vascular network reconstruction and bone regeneration in vivo. The findings of this research offer a promising research perspective for the design of vascularizing implants.

Comparative evaluation of autologous dental bone powder and deproteinized bovine bone mineral allografts for oral implant bone deficits.

To compare the effectiveness of autologous dental bone powder grafts with deproteinized bovine bone mineral (DBBM) allografts in oral implant bone deficiency. Between January 2021 and January 2023, we enrolled 120 patients with inadequate bone for oral implantation, dividing them into an experimental group and a control group (60 each). The experimental group received autologous dental bone powder grafts, while the control group received DBBM allografts. Wound healing was assessed using the early healing index (EHI) with 5 days of closure as the baseline timeline, as Grade I: full closure without a fibrin line, Grade II: closure with a fibrin line, and Grade III: closure with fibrin covering the incision. Additional outcomes included buccal and palatal alveolar bone height, alveolar bone width at 3 (W1), 7 (W2), and 11mm (W3) below the top of the alveolar ridge, and bone density measured before and 3 months after tooth extraction. The altered shape of the alveolar bone at the extraction site was assessed at 3- and 6-months post-extraction. Implant success rate was also evaluated at 15 days and 1 month after implantation. Comparisons were made using independent t-tests, paired t-tests, χ² tests, and Z tests, as appropriate. The experimental group had a lower wound healing time and a greater prevalence of EHI categorization class I compared to the control group (P < 0.05). Three months after tooth extraction, there was no statistically significant difference in buccal and palatal alveolar bone heights between the experimental group and the pre-treatment measurements (P > 0.05). However, the control group showed a decrease in buccal and palatal alveolar bone heights compared to the pre-treatment period, while the experimental group had greater bone heights than the control group (P < 0.05). Three months after extraction, the widths of W1, W2, and W3 decreased in both groups. However, the experimental group maintained greater widths compared to the control group (P < 0.05). At 3 months post-extraction, both groups showed an increase in alveolar bone density at the extraction site. Notably, the experimental group had a higher bone density compared to the control group as well as new bone contour score of the alveolar bone at the extraction site (P < 0.05). However, at 6 months after extraction, there was no statistically significant difference in the new bone contour score of the alveolar bone at the extraction site between the two groups (P > 0.05). There was no significant difference in the implant success rate between the two groups. (P > 0.05). Autologous dental bone powder grafting promotes initial alveolar bone regeneration, enhances wound healing, and increases new bone density, providing favorable surgical conditions for dental implants. However, by 6 months, there was no significant difference in bone contour compared to DBBM allografts, indicating similar long-term clinical outcomes for both materials.

Comparing the performance of a femoral shaft fracture fixation using implants with biodegradable and non-biodegradable materials.

Orthopedic injuries, such as femur shaft fractures, often require surgical intervention to promote healing and functional recovery. Metal plate implants are widely used due to their mechanical strength and biocompatibility. Biodegradable metal plate implants, including those made from magnesium, zinc, and iron alloys, offer distinct advantages over non-biodegradable materials like stainless steel, titanium, and cobalt alloys. Biodegradable implants gradually replace native bone tissue, reducing the need for additional surgeries and improving patient recovery. However, non-biodegradable implants remain popular due to their stability, corrosion resistance, and biocompatibility. This study focuses on designing an implant plate for treating transverse femoral shaft fractures during the walking cycle. &#xD;The primary objective is to conduct a comprehensive finite element analysis (FEA) of a fractured femur's stabilization using various biodegradable and nonbiodegradable materials. The study assesses the efficacy of different implant materials, discusses implant design, and identifies the optimal materials for femoral stabilization. Results indicate that magnesium alloy is superior among biodegradable materials, while titanium alloy is preferred among non-biodegradable options. The findings suggest that magnesium alloy is the recommended material for bone implants due to its advantages over non-degradable alternatives.&#xD.

Composite Scaffold Materials of Nanocerium Oxide Doped with Allograft Bone: Dual Optimization Based on Anti-Inflammatory Properties and Promotion of Osteogenic Mineralization.

Spinal fusion technique is widely used in the treatment of lumbar degeneration, cervical instability, disc injury, and spinal deformity. However, it is usually accompanied by a high incidence of fusion failure and pseudoarthrosis, placing higher demands on bone implants. Therefore, materials with good biocompatibility, osteoconductivity, and even induce bone ingrowth, which can be used to improve spinal fusion rate and bone regeneration, have become a hot research topic. Here, ultra-small cerium oxide nanoparticles (CeO2 NPs) are prepared and loaded onto the surface of the homograft bone surface to prepare a composite scaffold AB@PLGA/CeO2. The composite scaffold shows the competitive ability to promote osteoblast differentiation in vitro. In vivo experiments show that AB@PLGA/CeO2 has a good bone enhancement effect. In particular, good biological effects of collagen fiber formation, osteogenic mineralization, and tissue repair are shown in intervertebral implant fusion. Further, transcriptome sequencing confirms that CeO2 NPs promote osteogenic differentiation and mineralization by regulating extracellular matrix (ECM) and collagen formation. Meanwhile, CeO2 NPs can regulate the function of the PI3K-Akt signaling pathway to exert its ability to promote osteogenic differentiation and mineralization and affect p53 and cell cycle signaling pathway to regulate osteogenic differentiation and mineralization. Hence, the proposed scaffold is a promising strategy for intervertebral fusion in the clinic.

Comparative Evaluation of Bone–Implant Contact in Various Surface-Treated Dental Implants Using High-Resolution Micro-CT in Rabbits’ Bone

This study evaluated the bone-to-implant contact (BIC) of various surface-treated dental implants using high-resolution micro-CT in rabbit bone, focusing on the effects of different treatments on osseointegration and implant stability before and after bone demineralization. Six male New Zealand White rabbits were used. Four implant types were tested: machined surface with anodizing, only etching, sandblasting with Al2O3 + etching, and sandblasting with TiO2 + etching. Implants were scanned with high-resolution micro-CT before and after demineralization. Parameters like implant volume, surface area, and BIC were determined using specific software tools. During demineralization, the BIC changed about 6% for machined surface with anodizing, 5% for only etching, 4% for sandblasting with Al2O3 + etching, and 10% for sandblasting with TiO2 + etching. Demineralization reduced BIC percentages, notably in the machined surface with anodizing and sandblasting with TiO2 + etching groups. Etching and sandblasting combined with etching showed higher initial BIC compared to anodizing alone. Demineralization negatively impacted the BIC across all treatments. This study underscores the importance of surface modification in implant integration, especially in compromised bone. Further research with larger sample sizes and advanced techniques is recommended.

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.

Does an Osteoporosis-like Condition Jeopardize the Osseointegration Process around Dental Implants Placed in Animal Models? A Systematic Review.

Knowing that osteoporosis is a metabolic disease that could decrease dental implant success and survival, the purpose of this review was to gather information on the characteristics of implant osseointegration in animal models of induced osteoporosis. By pointing out the role of some factors that could improve the success rate in these situations, this study aimed to enhance the knowledge about this process that can be further translated to clinical designs. A systematic search in PubMed/Medline, Lilacs, Cochrane Library, Scopus and Web of Science was conducted to identify information between 2002 and 2023 regarding osseointegration of dental implants in animal models of induced osteoporosis. The following search strategy was utilized and adjusted to each database: (((dental implant) AND (Osseointegration)) AND (osteoporosis)) AND/OR (osteoporosis treatment). The inclusion criteria were animal studies in English, involving the placement of an osseointegrated implant in osteoporotic bone, and evaluating bone to implant contact (BIC) %. Exclusion criteria were studies in humans, in vitro studies, procedures involving any kind of bone graft and studies evaluating medication related osteonecrosis of the jaw. A standardized data extraction form was used to record data for each study, covering article title, date, authors, number of animals, purpose of study, type of analysis used by authors, follow-up, type of implant, test and control groups, intervention and conclusions. The risk of bias of the included studies was assessed using the Systematic Review Centre for Laboratory animal Experimentation (SYRCLE) Risk of Bias tool.20 Results: A total of 204 articles were found for evaluation and selection. All of the 43 selected studies evaluated the bone-implant contact (BIC) %. Other parameters such as bone to implant mechanical interface, bone area (BA) and bone volume (BV) ratio were also evaluated in some of the studies. There was a tendency for compromised results of implant osseointegration in the presence of osteoporosis. Modification of the implant surface, systemic and local use of anti-resorptive drugs and other substances, showed benefits for the implant success in osteoporotic sites. Still, no consensus among studies on the superiority of systemic medications in improving the process of peri-implant bone repair, was observed. Although it is possible to improve the osseointegration of implants in osteoporotic bone, either by using systemic or local factors, the metabolic bone syndrome caused by osteoporosis can jeopardize the osseointegration of dental implants.

KH571 construct interfacial molecular bridge in calcium silicate/TMPTA/HDDA scaffolds for improving mechanical properties, biodegradability and photopolymerization

Digital Light Processing (DLP) offers the potential for personalized bone implants. Within this method, the interfacial bonding capacity of inorganic/organic materials and the solid-phase content of the slurry emerge as primary factors influencing scaffolds mechanical properties. In this research, KH571 was applied to establish an interfacial “molecular bridge”, adopting in situ coupling technology to forge stable covalent bonds between calcium silicate (CSi) and KH571. Chemical grafting, surface photografting, and photopolymerization techniques were then utilized to construct a photo-crosslinked network by CSi-KH571-TMPTA/HDDA slurry, thereby transforming the weak physical connections at the interface into strong chemical bonds. Consequently, the curing capacity and mechanical properties of the scaffolds were enhanced. Further control grain size, crystal phase transition, and shrinkage of CSi-KH571 scaffolds, post-treatment sintering processes were employed, resulting in scaffolds with a high content of β-CSi. Moreover, the optimal process parameters were selected concerning grafting rate, chemical composition, microscopic morphology, crystalline transformation, dimensional accuracy, mechanical properties, biodegradability and biocompatibility of CSi-KH571. The elastic modulus and compressive properties of CSi25-55 scaffolds exhibited a notable improvement of 29.71 % and 59.30 %, respectively, compared to CSi-50 scaffolds. By regulating the phase composition of CSi, CSi25-55 scaffolds were designed to possess a controllable degradation. In vitro cell culture experiments validated its excellent biocompatibility and promoted the proliferation and differentiation of bone marrow mesenchymal stem cells (BMSCs) as well as the deposition of bone matrix. Herein, a novel and sustainable approach has been promoted for enhancing the interfacial bonding capacity of inorganic/organic materials and the solid-phase content of printing slurry, which lays the foundation for the printing of high-resolution degradable bioceramic scaffolds.

Electrophoretic deposition of curcumin-loaded mesoporous bioactive glass nanoparticle-chitosan composite coatings on titanium for treating tumor-induced bone defect

Clinical treatment of osteosarcoma (OS) presents significant challenges in postoperative tumor recurrence and large segmental bone defects, often necessitating joint replacement or artificial bone implantation to repair failed or defective bone tissue. At the same time, fibroblastic encapsulation can impede direct contact between implants and bones, leading to implant failure. To tackle these issues, mesoporous bioactive glass nanoparticles (MBN) were synthesized and then loaded with curcumin (CUR). Subsequently, chitosan (CTS) was chosen as the charger and coating matrix, and electrophoretic deposition (EPD) was utilized to fabricate a CTS-MBN-CUR composite coating with triple functionality on Ti implants aiming for OS-induced bone repair. MBN-CUR nanoparticles are encapsulated in CTS and uniformly distributed within the coating, achieving robust adhesion and long-term release of CUR. Concurrently, the developed CTS-MBN-CUR coating exhibits moderate hydrophilicity, and good bioactivity. Moreover, three different types of cells, MC3T3-E1, L929, and MG63 cells, were individually cultured with the composite coating and subjected to comprehensive cellular studies. The coating presented favorable bioactivities, and osteogenic performance, and the ability to resist the activity of fibroblast and OS cells. These findings suggest that CTS-MBN-CUR holds promising potential for bone regeneration following OS resection surgery.

Tailoring β-Ti based shape memory alloy with the exceptional mechanical and functional properties towards biomedical bone implants application

In the present study, the interstitial hydrogen (H) atoms were introduced as β-stabilizing element to tailor the microstructure, martensitic phase transition, and functional properties of Ti-V-Al shape memory alloys for biomedical applications. The results revealed that the addition of interstitial H atoms into Ti-V-Al shape memory alloys induced the transition from a single αˊˊ martensite to the coexistence of β parent phase and α phase, regardless of H content. Moreover, the amount of α phase firstly increases and then decreases in the present Ti-V-Al based shape memory alloy with H content increasing. Besides, H addition resulted in larger lattice distortion, further causing the formation of nano-domains in Ti-V-Al based alloys. Besides, no endothermic and exothermic peaks were detected due to the confinement of α-phase, and the emergence of nano-domains. With increasing H atoms content, the mechanical properties such as fracture strength, hardness, recoverable strain for Ti-V-Al based shape memory alloys initially increased and then decreased. (Ti-13V-3Al)99.2H0.8 shape memory alloys exhibited the highest fracture strength of 862MPa, superior hardness of 307HV, and the fully recoverable strain under 6% pre-strain as well as the moderate elastic modulus, which was mainly attributed to the solution strengthening of interstitial H atoms and the precipitation strengthening of α phase. The best corrosion resistance of Ti-V-Al based shape memory alloys was observed with the 2.0at. % H, which was due to the formation of TiO2, Ti2O3 oxide films. Moreover, the best wear resistance with the lower wear rate of 0.9347×10-6 mm3/N mm was obtained in (Ti-13V-3Al)99.2H0.8 shape memory alloy, due to the integrated effects of higher microhardness, reinforcing effect of α phase and lubrication effect of the hydrogenated film.

Calcium Silicate Promoting the Upcycling Potential of Polysulfone Medical Waste in Load-Bearing Applications

Polysulfone (PSF) medical waste can be effectively repurposed due to its excellent mechanical properties. Due to the increasing need for load-bearing bone implants, it is crucial to prioritize the development of biocompatible polymer–matrix composites. Calcium silicate (CaSi), known for its osteogenesis and antibacterial properties, is widely used in medical applications. In this study, recycled PSF plastics in fiber or nanoparticle forms and commercial PSF products were used to create PSF-based composites filled with three different amounts (10, 20, and 30 vol%) of CaSi. The green compact was heat-treated at various temperatures. Experimental results showed that the mechanical interlocking of the PSF matrix and CaSi filler occurred due to the liquefaction of PSF fibers or nanoparticles during heat treatment. When the composite contained 20% CaSi, the obtained three-point bending strength exceeded 60 MPa, falling within the reported strength of compact bone. There was a concurrent improvement in the biocompatibility and antibacterial activity of the PSF-based composites with the increasing amount of CaSi. Considering their mechanical properties and antibacterial activity, the 20% CaSi-containing PSF-based composites treated at 240 °C emerged as a promising candidate for bone implant applications. This study demonstrated the feasibility of upcycling medical waste such as PSF as a matrix, opening doors for its potential usage in the medical field.

Development of Fe-Cr-C alloys with high Mn content for bone implant

The object of this study is to combine the properties of Mn and the advantages of Fe-Cr-C to improve biomaterial compatible characteristics. Three alloys of Fe-Cr-C with compositions of 12 wt. % Mn, 16 wt. % Mn, and 20 wt. % Mn, were investigated. Microstructural analysis was carried out using a scanning electron microscope (SEM), and a Vickers hardness test kit was used to evaluate the hardness. The pin-on-disc method was used for the dry slide wear test, and the corrosion test was carried out using the three-electrode cell polarization method. The hardness value of Fe-Cr-C alloy increased by 28.7 % with the increase of Mn content from 12 wt. % (231.8 VHN) to 20 wt. % (298.4 VHN). The tensile strength value increased by 30.3 % with an increase in Mn content from 12 wt. % (522.69 MPa) to 20 wt. % (680.89 MPa), while the strain value decreased by 30.9 %. However, impact toughness did somewhat decline, from 0.213 J/mm2 at 12 wt. % Mn to 0.169 J/mm2 at 20 wt. % Mn. The wear rate results for Fe-Cr-C 20 wt. % Mn 0.000156 mm3/kg. show a reduction of more than 15 wt. % when compared to Fe-Cr-C 12 wt. % Mn because of an increase in the hard-intermetallic area. Additionally, corrosion resistance improved significantly, with the corrosion rate decreasing from 0.005814 mm/yr at 12 wt. % Mn to 0.001780 mm/yr at 20 wt. % Mn, demonstrating that higher Mn content reduces material degradation in corrosive environments. Based on the experimental results, Fe-Cr-C 20 wt % Mn alloy has the highest mechanical and corrosion resistance of the three types of alloys. Fe-Cr-C with high Mn alloys are promising candidates for application as biomaterials for bone implants by optimizing the Mn content and corrosion resistance

The Deposition of Hydroxyapatite Particles Within an Organic Matrix on the Surface of Poly(lactic acid).

Hydroxyapatite (HAP) is a well-established material in biomedical applications, especially for bone tissue regeneration, dental implants, and drug delivery systems. Recent research emphasizes enhancing the biocompatibility and osteoconductivity of orthopedic implants using HAP. This study explores the potential of combining HAP with a lipid matrix to improve the surface properties and biocompatibility of poly(lactic acid) (PLA)-based, 3D-printed, resorbable bone implants. We utilized the Langmuir-Blodgett method to deposit HAP within a dihexadecyl phosphate (DHP) matrix onto PLA substrates. This study demonstrates that DHP and HAP form stable monolayers at the air/water interface with HAP particles distributed within a homogeneous lipid matrix. The presence of HAP and the resulting changes in surface free energy (SFE) are hypothesized to enhance the biocompatibility of PLA implants. Our findings indicate that films composed of DHP + HAP 5:1 are particularly effective in altering PLA surface characteristics, potentially improving osteointegration, and reducing microbial adherence. Overall, this work highlights that surface modification of PLA with HAP and lipid matrices is the first step towards new, promising, and cost-effective strategies for developing advanced biomaterials for bone regeneration.

Effect of Structural Configurations on Mechanical and Shape Recovery Properties of NiTi Triply Periodic Minimal Surface Porous Structures

Based on the advantages of triply periodic minimal surface (TPMS) porous structures, extensive research on NiTi shape memory alloy TPMS scaffolds has been conducted. However, the current reports about TPMS porous structures highly rely on the implicit equation, which limited the design flexibility. In this work, novel shell-based TPMS structures were designed and fabricated by laser powder bed fusion. The comparisons of manufacturability, mechanical properties, and shape recovery responses between traditional solid-based and novel shell-based TPMS structures were evaluated. Results indicated that the shell-based TPMS porous structures possessed larger Young’s moduli and higher compressive strengths. Specifically, Diamond shell structure possessed the highest Young’s moduli of 605.8±24.5 MPa, while Gyroid shell structure possessed the highest compressive strength of 43.90±3.32 MPa. In addition, because of the larger specific surface area, higher critical stress to induce martensite transformation, and lower austenite finish temperature, the Diamond shell porous structure exhibited much higher shape recovery performance (only 0.1% residual strain left at pre-strains of 6%) than other porous structures. These results substantially uncover the effects of structural topology on the mechanical properties and shape recovery responses of NiTi shape memory alloy scaffolds, and confirm the effectiveness of this novel structural design method. This research can provide guidance for the structural design application of NiTi porous scaffolds in bone implants.

Personalized Stem Length Optimization in Hip Replacement: A Microscopic Perspective on Bone—Implant Interaction

Total hip replacement (THR) surgery involves the removal of necrotic tissue and the replacement of the natural joint with an artificial hip joint. The demand for THR is increasing due to population aging and prolonged life expectancies. However, the uniform length and shape of artificial hip joints can cause stress shielding, leading to implant loosening and femoral fractures. These issues arise because these designs fail to account for the unique anatomical and biomechanical characteristics of individual patients. Therefore, this study proposes and validates a method to optimize stem length by considering bone microstructure and daily load. The results demonstrated that the optimal stem length varies with loading conditions and significantly reduces stress in the cortical bone while maintaining an appropriate strain energy in the cancellous bone, thereby preventing bone loss. These findings underscore the importance of patient-specific stem design for improving implant stability and clinical outcomes.

Effect of prophylactic infusion of norepinephrine on the prevention of hypotension during vertebroplasty: a randomized clinical trial

BackgroundTransient hypotension is a common occurrence during the implantation of bone cement. This placebo-controlled randomized clinical trial study investigated the effect of prophylactic infusion of norepinephrine on the incidence of hypotension in senior patients who underwent vertebroplasty.MethodsThe trial recruited patients who were greater than or equal to 65 years of age, had an American Society of Anesthesiologist physical status classification of I to III, and underwent vertebroplasty from August 2020 to August 2021 at the Affiliated Hospital of Integrated Traditional Chinese and Western Medicine, Nanjing University of Chinese Medicine in China. The patients were randomly grouped according to whether they received either a norepinephrine infusion of 0.05 µg/kg/min or an equivalent volume of saline 10 min before implantation of bone cement. Intraoperative hemodynamics were monitored continuously by the MostCare system at the following 7 time points: 10 min before implantation of bone cement and immediately, 30 s, 1, 3, 5, and 10 min after implantation of bone cement. We also recorded the number of hypotensive episodes and the total number of vasopressors after implantation of bone cement. Multivariable logistic regression was used to assess the risk factors associated with hypotension after implantation of bone cement.ResultsA total of 63 patients were randomized to the control group (n = 31; median [IQR] age, 74 [69–79] years) and the norepinephrine group (n = 32; median [IQR] age, 75 [71–79] years). The incidence of hypotension in the norepinephrine group was significantly lower than that in the control group after implantation of bone cement (12.5% vs. 45.2%; relative risk [RR], 3.61 [95% CI, 1.13–15.07]; P = 0.005). Moreover, the median (IQR) number of hypotensive episodes (0 [0–0] vs. 0 [0–2]; P = 0.005) and the total number of vasopressors (0 [0–0] vs. 0 [0–1]; P = 0.004) in the norepinephrine group were significantly lower than those in the control group. Furthermore, compared with the baseline, the MAP significantly decreased at 1 min (P = 0.007) and 3 min (P < 0.001) after bone cement implantation in the control group. However, the MAP at 3 min in the norepinephrine group was significantly higher than that in the control group (P < 0.001). The incidence of complications was not different between the groups. In multivariable logistic regression, the FRAIL score (OR, 2.29; 95% CI, 1.21–4.31) was identified as a risk factor associated with hypotension.ConclusionProphylactic infusion of norepinephrine before bone cement implantation can stabilize hemodynamics and reduce the incidence of hypotension after implantation of bone cement.

A 10-year Retrospective Clinical Study to Identify Risk Indicators for Peri-Implant Bone Loss and Implant Failure.

To evaluate long-term survival and success of dental implants and evaluate indicators affecting the long-term outcome. Implant survival, success and crestal bone loss (BL) over time were evaluated. For covariates at patient level, Kaplan-Meier estimates of implant survival were compared between groups with the log-rank test. Observed mean bone loss (MBL) was plotted as a function of time. Cumulative frequencies of BL were plotted for different post-op times. Uni- and multivariate analysis was performed. Simple linear mixed and multiple linear mixed models for BL at 1, 5 and 10 years were fitted. 407 patients (221 women, 186 men; mean age 64.86 years (range 28-92, SD 10.11)), with 1482 implants, responded. Absolute implant survival was 94.74%; MBL was 0.81 mm (SD 1.58, range 0.00-17.00) after an average follow-up of 10.66 years (range 10-14, SD 0.87). Implant survival was influenced on implant level by smoking, implant width and early bone loss (EBL) > 0.5 mm; on patient level by a history of periodontitis. Indicators influencing MBL after the 1st year were abutment height, type of surgery and implant width, while after 5 and 10 years of function were abutment height, EBL > 0.5 mm and smoking. Implant survival was significantly affected by a history of periodontitis on patient level and by smoking, implant width and EBL > 0.5 mm on implant level. Late bone loss was significantly affected by abutment height, EBL > 0.5 mm and smoking. B670201524796.

Fabrication and in vitro biological properties of hydroxyapatite-sodium potassium niobate-barium titanate piezoelectric bioceramics

The utilization of piezoelectric materials in bone implants is appealing due to the inherent piezoelectric property of natural bone. The intrinsic electrical characteristics of piezoelectric biomaterials enhance antibacterial activities, biocompatibility, and bioactivity properties. This study delves into investigating the antibacterial properties, biocompatibility, and bioactivity of three-component biocomposites: sodium potassium niobate (KNN)-barium titanate (BT)-hydroxyapatite (HA). The combination of sodium potassium niobate and barium titanate, possessing suitable piezoelectric properties, with hydroxyapatite, known for its favorable biological properties, enhances the requisite properties for a bone implant. Among the various compositions studied, the combination comprising 70 wt% of the piezoelectric component (KNN-BT) and 30 wt% hydroxyapatite, labeled as 30HKB, emerged as the most optimal blend in terms of density, morphotropic phase boundary, and other biological tests conducted. Following polarization, the antibacterial efficacy of 30HKB against S. aureus bacteria cells increased by 61 %. Furthermore, the growth and adhesion of MC3T3-E1 osteoblast cells suggest enhanced biocompatibility of the 30HKB composite attributed to surface polarization. The surface charges generated by polarization facilitated the absorption of Ca2+ ions, as well as the interaction of HPO4 - and OH- ions with the precipitated Ca2+ ions, leading to the formation of the CaP layer. Hence, polarized piezoelectric ceramics exhibit heightened bioactivity compared to their non-polarized counterparts.

A comprehensive study of LPBF parameter influence in 316L stainless steel mechanical properties, macrostructure, and printability

Additive manufacturing, particularly using Laser Powder Bed Fusion (LPBF) technologies with 316L stainless steel, has proven highly promising in biomedical engineering due to the material’s exceptional mechanical properties and biocompatibility. This study, which is a foundational step towards developing porous bone implants, focuses on assessing the influence of a broad range of parameters - spot size, scanning speed, laser power, and energy density - on the mechanical performance and structural integrity of 316L stainless steel parts across three distinct specimen geometries: fully dense parallelepipedic, fully dense cubic, and cellular (lattice) specimens. By analysing 17 different parameter sets and producing over 150 specimens, a thorough series of experimental tests were conducted, including flexural tests, compression tests, hardness tests, macroscopic evaluation of the surface of fully dense specimens, and macroscopic evaluation of the lattice structures.e in powder accumulation within the pores of cellular structures, with higher energy densities (100 J/mm3) leading to a significantly greater retention compared to lower energy densities (66 J/mm3). This underexplored phenomenon has significant implications for the selection of parameters in the fabrication of bone implants. Further research is needed to refine LPBF printing parameters and enhance the quality of porous bone implants.