Search Results (287)

Additive manufacturing (AM) has expanded the design space of biomaterials for biomedical engineering, enabling patient-specific geometries, controlled porosity, multi-material constructs and cell-compatible fabrication. However, clinical translation remains constrained by a mismatch between fabrication capability and biological, mechanical and regulatory performance. Unlike reviews focused on individual material families, isolated AM routes or specific applications, this review interprets AM of biomaterials as an integrated biomaterial–process–structure–property–translation ecosystem. It examines how material chemistry, feedstock state, printing route, architecture, post-processing and biological response jointly determine the reliability of acellular and cellular constructs, with particular emphasis on clinically relevant performance, reproducibility and long-term safety. Metallic, ceramic, polymeric, hydrogel-based and composite biomaterials are analysed alongside binder jetting (BJ), directed energy deposition (DED), material extrusion (ME) and jetting (MJ), powder bed fusion (PBF), VAT photopolymerisation and bioprinting. The review identifies recurring challenges across routes, including restricted material–process compatibility, limited prediction of process–structure–property relationships, post-processing-induced changes in biological performance, insufficient standardisation of printability and biofunctionality metrics, incomplete validation of cell-laden and vascularised constructs and weak transfer of laboratory protocols to clinically robust workflows. The main conclusion is that progress will depend less on expanding printable geometries alone and more on integrated optimisation of materials, processing windows, structural fidelity, biological validation, quality assurance and translational readiness. This ecosystem-level perspective provides a framework for evaluating limitations and defining future priorities in AM-based biomaterials for regenerative medicine, implants and precision biomedical engineering. Full article

Background and Objectives: Periodontal health represents a condition characterized by homeostasis between the teeth and the surrounding supporting tissues and implies the absence of inflammation, confirmed by the lack of bleeding, epithelial attachment loss, mobility, or periodontal pocket formation. Fixed prosthetic restorations may compromise periodontal health already during the fabrication phase, given that decisions made during their planning and placement affect long-term clinical outcomes. The aim of this manuscript was to provide insight into the interaction between periodontal tissues and fixed prosthetic restorations. Materials and Methods: A narrative literature review was conducted using a structured search of the PubMed/MEDLINE, Scopus, and Google Scholar databases to identify studies addressing periodontal health in relation to fixed dental prostheses. The impacts of tooth preparation, gingival retraction methods, supracrestal tissue attachment, periodontal phenotype, crown emergence profile, and marginal fit of various biomaterials were analyzed. Results: According to the literature data, subgingival margin placement and violation of the supracrestal tissue attachment (biological width) induce chronic inflammation, loss of epithelial attachment, and alveolar bone resorption. Gingival retraction agents, used in chemomechanical retraction procedures, particularly ferric sulfate-based agents, may lead to a transient but significant spike in inflammatory markers and dysbiosis of the subgingival microbiome. Contemporary approaches, such as the biologically oriented preparation technique and the use of CAD/CAM (Computer-Aided Design and Computer-Aided Manufacturing) technology, may improve the precision of marginal fit. Zirconia restorations exhibit significantly better biocompatibility and reduced microbial adhesion compared to metal–ceramic restorations. Conclusions: Biological response of the periodontium to fixed prosthetic restorations depends on the complex interaction between the material, position of the marginal line, and oral hygiene control. Regardless of the material used or the fabrication technique employed, adequate plaque control and regular maintenance remain key factors in preserving periodontal health. Full article

Cementation of indirect restorations has undergone a profound change over the past century, evolving from a philosophy of purely mechanical cementation to sophisticated biomaterials science based on adhesion. The aim of this narrative review is to provide essential context for understanding contemporary clinical decision-making. A key aspect is the structural and compositional characteristics of enamel and dentin as bonding substrates, underlining why enamel remains the gold standard, while dentin continues to present significant challenges. The synthesis is based on evidence of adhesive strategies for the four main classes of contemporary restorative materials, such as glass-ceramics (lithium disilicate and leucite), polycrystalline zirconia, resin-matrix ceramics (hybrid ceramics), and indirect composites. Each material was detailed in terms of surface penetration (e.g., hydrofluoric acid etching and air abrasion), chemical coupling (e.g., silanization and MDP-based primers), and appropriate resin cement selection (light-cured, dual-cured, or self-adhesive). A step-by-step clinical protocol is synthesized based on current evidence, integrating critical techniques such as immediate dentin sealing and optimized polymerization. This review concludes that while adhesive resin cements provide predictable long-term results, significant challenges remain, guiding future clinical research and innovation. Full article

This article presents a systematic analysis of the application of advanced mathematical and computational approaches in dental bioengineering, with a focus on biomaterials processing and machining-related technologies. The aim is to critically synthesize current knowledge on the use of numerical simulations, statistical modeling, and algorithm-based methods in the analysis and optimization of technological processes in dentistry. The review was conducted following the PRISMA framework to ensure a transparent and reproducible selection of relevant studies addressing the intersection of dental applications, manufacturing processes, and computational modeling. The results reveal that the current research does not constitute a unified modeling framework, but rather a heterogeneous set of approaches targeting specific aspects of biomaterial processing. The analyzed studies demonstrate the application of finite element analysis, empirical statistical models, and geometry-based computational methods, particularly in processes such as drilling and grinding of ceramic dental materials. These approaches enable detailed analysis of mechanical and thermal loading conditions, as well as partial optimization of process parameters. However, their applicability is often limited by their empirical nature, lack of integration, and insufficient linkage to real-time process control. The synthesis highlights a significant research gap in the development of integrated and multiphysics modeling frameworks capable of combining mechanical, thermal, and geometrical aspects of machining processes. Future research should focus on the implementation of digital twins, adaptive process control, and personalized modeling strategies to enhance the accuracy, efficiency, and predictability of dental biomaterial processing. Full article

Surface functionalization of metallic implants is widely explored to enhance their performance and functionality. In this study, multifunctional hydrogel coatings based on poly(vinylpyrrolidone) and polyethylene glycol were developed and functionalized with a taxifolin (TAX) inclusion complex and collagen to introduce bioactive features. TAX, a naturally occurring flavonoid with antioxidant and anti-inflammatory properties, was incorporated using β-cyclodextrin to improve its stability and enable controlled release. The coatings were applied to titanium-hydroxyapatite composites and titanium sheet substrates to evaluate their applicability across surfaces with varying morphologies, ranging from porous to relatively smooth. The ceramic phase was modified with magnesium ions to enhance its bioactivity and better mimic the composition of natural bone tissue. FTIR and SEM analyses confirmed hydrogel formation and effective surface coverage. Degradation and incubation studies in simulated physiological environments demonstrated the material’s stability, while UV–Vis analysis indicated TAX release, highlighting the system’s potential as a carrier for flavonoid-based compounds. Indirect cytotoxicity studies using MC3T3-E1 preosteoblasts indicated low cytotoxicity and a favorable biological response of collagen- and taxifolin-modified systems. The developed coatings represent a versatile platform for surface modification of titanium-based biomaterials and demonstrate potential for application across substrates with diverse surface characteristics. Further studies are required to assess their biological potential. Full article

Critical size bone defects (CSBD) remain a major challenge in orthopedic surgery. Autologous bone grafting is considered the gold standard but is limited by restricted availability and significant donor-site morbidity. Synthetic bone substitutes offer an alternative; however, these materials are avital and lack osteoinductive properties. This study evaluated whether intraoperative bioactivation of bone substitutes using a surgical suction handle can safely enhance their regenerative potential. Fifty patients with CSBD, non-unions, or high-risk defects were enrolled, and calcium phosphate-based ceramics were intraoperatively coated with autologous tissue via a surgical suction handle and implanted into the defects. Clinical outcomes—including pain, range of motion, and wound healing—were scored using a standardized system, with all patients achieving results in the “excellent” range (10–13 points). Radiographic follow-up showed progressive cortical and extracortical bone formation in all patients. Surgeons reported high ease-of-use for the device, and no device-related complications occurred. Although biomaterial resorption was incomplete in some cases (36% with <75% resorption at six months), no patient required revision surgery. Our data indicate that intraoperative bioactivation of bone substitutes using a surgical suction handle is safe, feasible, and promotes local bone regeneration, providing a minimally invasive and practical approach to enhance the performance of synthetic grafts in challenging defects. Full article

(1) Background: The development of advanced dental biomaterials has significantly improved restorative dentistry, shifting the focus from purely mechanical restoration toward materials capable of interacting biologically with oral tissues. Modern restorative materials are expected to demonstrate high biocompatibility, adequate mechanical properties, and potential bioactivity that may support tissue preservation and long-term clinical performance. This review aims to analyze recent advances in next-generation dental restorative materials and to evaluate their biological compatibility and potential clinical relevance. (2) Methods: A narrative literature review was conducted using major scientific databases, including PubMed, Scopus, and Web of Science, focusing on studies addressing advanced polymer-based composites, bioactive restorative materials, dental ceramics, computer-aided design and computer-aided manufacturing (CAD–CAM) restorative systems, and nanostructured biomaterials used in restorative dentistry. Relevant studies published in recent years were analyzed with respect to material composition, biological response, and reported clinical performance. (3) Results: The reviewed literature indicates that modern dental biomaterials, including nanocomposites, bioactive glass-containing materials, calcium silicate–based systems, and hybrid ceramic materials, show improved mechanical stability, enhanced remineralization potential, and reduced bacterial adhesion compared with traditional restorative materials. Advances in nanotechnology and material engineering have also contributed to the development of antimicrobial and bioactive restorative systems. (4) Conclusions: Next-generation dental restorative materials demonstrate promising characteristics that may improve clinical outcomes and biological integration in restorative dentistry; however, further long-term clinical investigations are required to fully confirm their safety, durability, and long-term effectiveness. Full article

This review summarizes the base materials, joining methods, filler materials, and principal technical challenges in endoscope joining fabrication, and proposes practical strategies to improve joint reliability under clinical constraints. We conducted a comprehensive search in multiple databases, including Web of Science, Google Scholar, patent databases, Scopus databases, and Medline (via PubMed), for articles on the joining for precision endoscope fabrication, covering the period from 1950 to 2026. We employed the combinations of keywords, “endoscopy”, “minimally invasive surgery”, “welding”, “joining”, “sealing”, “soldering”, “bonding”, and “brazing”. Approximately 500 references were retrieved. After excluding duplicates and irrelevant studies, 158 publications met the inclusion criteria. Data on base materials, joining, processes, filler materials, and technical issues related to sterilization, corrosion, and microstructural evolution were extracted and analyzed. Endoscopes are multi-material systems, involving metallic biomaterials (stainless steels (SSs), titanium alloys, nickel-based alloys, etc.), optical functional materials (glass, sapphire, quartz, etc.), engineering plastics, ceramics, composite materials, and coatings. Joining, sealing, and functional integration have been achieved via adhesive bonding, laser soldering, laser brazing, wave soldering, reflow soldering, fusion welding, and other joining techniques. The main challenges include how to reliably join highly mismatched dissimilar materials, how to fabricate low-residual-stress joints, and how to increase the long-term resistance to sterilization-induced degradation and thermal aging over repeated 100–200 °C thermal cycles. Conventional joining techniques struggle to balance mechanical integrity, joint hermeticity, and long-term stability under such harsh cyclic conditions. The resulting joints may suffer surface yellowing, interfacial debonding, microcracking, delamination, or progressive property degradation during service. We propose the following three strategies to achieve reliable, low-residual-stress, and sterilization-resistant joining of dissimilar materials for endoscopes: (1) A synergistic design that combines thin-film engineering (including evaporation, sputtering, and electroplating) with silver anti-oxidation layers is proposed to reduce residual stresses and to enhance the joint hermeticity. (2) To develop principles for the selection of multi-joining processes to achieve the multi-material integration and functional assembly of dissimilar material components. (3) To develop the laser-based joining methods (fusion, brazing, or braze-welding) for precision control of heat input, bonding quality, and the least damage to the heat-sensitive components. Full article

Bone is a hierarchically organized composite material with unique mechanical properties and an intrinsic regenerative capacity that conventional repair strategies, including autografts, allografts, xenografts, and metallic or ceramic implants, fail to fully replicate due to donor scarcity, immunogenicity, mechanical mismatch, and poor long-term integration. Bone tissue engineering (TE) offers a biologically informed alternative by integrating osteoconductive scaffolds, osteogenic progenitor cells, and osteoinductive signaling molecules into a unified regenerative framework. Unlike existing reviews that evaluate these components in isolation, this review provides a mechanistically integrated analysis that repositions scaffold design as a biologically instructive platform whose topography, stiffness, porosity, and surface chemistry collectively govern cell adhesion, mechanotransduction, osteogenic differentiation, and extracellular matrix remodeling. Critically, it moves beyond cataloging materials and fabrication approaches to evaluate how specific scaffold features drive biological outcomes and to identify frequently understated limitations, including polymer-ceramic degradation kinetics and the inadequacy of small-animal models for clinical translation. By synthesizing advances in biomaterials, additive manufacturing, and smart scaffold technologies within this integrative framework, this review provides researchers and clinicians with a structured framework for evaluating emerging strategies and prioritizing future directions in functional bone regeneration. Full article

Bone tissue plays a vital role in the human body and possesses intrinsic self-repair mechanisms; however, large defects or pathological fractures may exceed its natural healing capacity. Bone tissue engineering provides promising strategies to restore bone integrity through the use of scaffolds, growth factors, and stem cells. While calcium phosphate (CaP)-based ceramics, such as hydroxyapatite (HAp) and tricalcium phosphate (TCP), represent the current benchmark, their limitations, including slow degradation (HAp) and limited osteoinductivity (TCP), have driven the development of alternative biomaterials. In this context, magnesium phosphate (MgP)-based materials have gained increasing attention due to their tunable resorption rate, improved biodegradability, and ability to stimulate osteogenesis and angiogenesis through the release of magnesium (Mg²⁺) ions. This study reports on composite scaffolds based on electrospun poly(ε-caprolactone) (PCL) fibres coated with MgP layers doped with lithium (Li) and zinc (Zn), designed to mimic the nanofibrous architecture of the extracellular matrix. Lithium and zinc were selected due to their known ability to modulate cellular response, with lithium promoting osteogenic activity and zinc contributing to improved cell proliferation and antibacterial potential. The phosphate phases obtained by coprecipitation were deposited onto the PCL fibres using Matrix-Assisted Pulsed Laser Evaporation (MAPLE), enabling controlled surface functionalization. Following thermal treatment, the formation of the crystalline magnesium pyrophosphate (Mg₂P₂O₇) phase was confirmed by chemical and structural characterization. The combination of a slowly degrading PCL matrix, providing sustained structural support, and a bioactive MgP coating, enabling rapid and controlled ion release, results in improved scaffold performance in terms of biocompatibility, biodegradability, and bioactivity. While the slow degradation rate of PCL ensures mechanical stability over an extended period, the surface-deposited MgP phase allows immediate interaction with the biological environment, facilitating faster ion release and enhancing cell–material interactions. These findings highlight the potential of the developed composites as promising candidates for trabecular bone regeneration and as viable alternatives to conventional CaP-based scaffolds in regenerative medicine. Full article

Lignocellulose represents an abundant repository of renewable carbon. Derived from various plant sources, it holds tremendous potential as a renewable and sustainable feedstock for the production of valuable chemicals and fuels. However, its solid fermentable compounds, cellulose and hemicellulose, are embedded within complex lignin structures and are therefore poorly accessible to microbial conversion. This paper describes an artificial rumen reactor (ARR) that uses anaerobic microbes from the cattle rumen to increase the release of fermentable carbon from recalcitrant biomass. We outline the development of an ARR for the efficient conversion of lignocellulosic grass into volatile fatty acids (VFAs), which are valuable precursors for the production of a range of bioproducts, including biofuels, biomaterials, and biochemicals. The ARR, a 4-L bioreactor equipped with a ceramic filtration unit, has been optimised and was operated for extended periods of continuous VFA production. Across distinct short- and long-term observation periods, and independent of the cow from which the rumen microbes originated, the bioreactor demonstrated the ability to sustain VFA production, indicating robustness and stability. At an input of 60–80 g dry grass d⁻¹, the system produced approximately 6 mol VFA per kg of dry matter input (DMI). The decoupling of the Solid Retention Time (SRT; 10 days) and the Liquid Retention Time (LRT; 0.5 days) prevented inhibition of the VFA production. The VFA profile was dominated by acetic and propionic acids, comprising 68% and 19%, respectively, with butyric acid and minor VFAs accounting for the remainder. The application of low oxygen levels (<10%) in the reactor via limited aeration did not affect the VFA yield or its profile. Full article

Multilayer zirconias have recently been introduced as dental biomaterials to combine improved translucency with sufficient mechanical reliability by implementing yttria-driven gradients in phase composition. Such materials can be considered functionally graded ceramics, where local phase stabilization influences strength and crack resistance. However, manufacturer-specific gradient profiles and their structure–property relationships remain insufficiently characterized. This study investigated two commercially available multilayer zirconias with distinct gradient concepts: IPS e.max^® ZirCAD Prime (continuous gradient) and KATANA™ Zirconia YML (stepwise gradient). Ten equidistant sections along the blank height were analyzed using quantitative X-ray diffraction and Rietveld refinement to quantify zirconia phase fractions and estimate local Y₂O₃ content. Mechanical behavior was evaluated by biaxial flexural strength testing (ball-on-three-balls method) and fracture toughness testing using the chevron-notched beam technique. Both materials exhibited pronounced yttria- and phase-dependent gradients consistent with their reported layer designs. Regions with increased yttria content showed higher t″ fractions and reduced fracture toughness and strength, whereas deeper regions displayed increased mechanical performance associated with higher fractions of transformable tetragonal phase. These findings emphasize that multilayer zirconias exhibit spatially dependent mechanical properties, which should be considered in biomaterial selection and restoration design, particularly when balancing aesthetic demands and fracture resistance. Full article

Piezoelectric biomaterials have attracted considerable interest in osteochondral tissue engineering owing to their inherent ability to produce electrical signals in response to mechanical stimuli without external power, thereby closely mimicking the physiological electrical microenvironment required for tissue regeneration. This review comprehensively summarizes recent insights into biological piezoelectricity from the molecular to the macroscopic level, highlighting its interplay with streaming potentials and its regulatory roles in bone and cartilage regeneration. We critically analyze recent advances in major piezoelectric material systems, including ceramics, polymers, and composite scaffolds, with emphasis on their structural characteristics, bioactive performance, and suitability for tissue-specific repair. Among them, polymer-based composite and hybrid piezoelectric scaffolds appear particularly promising for the development of flexible, high-performance osteochondral repair platforms, as they offer a more favorable balance between mechanical compliance, electromechanical output, and biological adaptability. Despite encouraging preclinical findings, significant challenges remain, including biocompatibility, controlled degradation kinetics, and the precise modulation of electrical cues for specific biological contexts. To address these barriers, future research should focus on optimizing scaffold design, integrating responsive and multimodal stimulation strategies, and establishing standardized protocols for preclinical evaluation and clinical translation. Overall, piezoelectric biomaterials hold substantial potential for the development of innovative regenerative therapies for complex osteochondral defects. Full article

Resin-matrix ceramics are among the increasingly preferred dental biomaterials in restorative dentistry. However, these materials are continuously exposed to staining from beverages in the oral environment, and continue to present limitations in terms of long-term aesthetic performance. This study was designed to evaluate the effects of different surface finishing procedures and immersion in commonly consumed beverages on the color change (ΔE₀₀) of four different resin-matrix ceramics (Cerasmart, Lava Ultimate, Shofu Block HC, and Vita Enamic). A total of 256 specimens were randomly assigned to mechanical polishing or glazing, then immersed in coffee, red wine, cola, or distilled water for 14 days. Data were analyzed using three-way repeated-measures analysis of variance (ANOVA), with Tukey and Bonferroni post hoc tests (α = 0.05). Surface finishing procedure, material type, beverage type and immersion time significantly affected ΔE₀₀ values (p < 0.05). The highest ΔE₀₀ values were observed at 14 days in the red wine-immersed glaze groups of Shofu Block HC (ΔE₀₀ = 7.44 ± 0.45) and Lava Ultimate (ΔE₀₀ = 7.24 ± 0.83). These findings suggest that surface finishing procedures and material selection play a critical role in preserving the aesthetic performance of resin-matrix ceramic restorations, and mechanical polishing may be considered a clinically favorable approach for computer-aided design and computer-aided manufacturing (CAD/CAM) restorations. Full article

Maxillary sinus augmentation is a key procedure for rehabilitating the atrophic posterior maxilla and enabling predictable implant-supported restorations. Although autogenous bone remains the biological gold standard due to its osteogenic potential, its clinical use has declined because of donor-site morbidity, limited availability, and increased surgical burden. Deproteinized bovine bone mineral (DBBM) is currently the most widely used substitute, providing excellent biocompatibility and long-term volumetric stability. However, its inert nature, limited bioactivity, and slow resorption have driven the development of next-generation graft materials. Recent biomaterial innovations aim to enhance vascularization, accelerate osteogenesis, modulate immune responses, and achieve controlled resorption while maintaining favorable handling properties. These include ion-releasing bioactive ceramics, growth factor-enhanced allografts, polysaccharide–hydroxyapatite composites, smart hydrogels, and synthetic scaffolds with tunable degradation profiles. Given the complexity of bone regeneration, effective clinical translation requires an integrated framework combining in vitro assays, animal models, and human clinical studies. This review synthesizes evidence published since 2018 on emerging biomaterials for sinus floor elevation, critically evaluating their potential to overcome the limitations of DBBM and highlighting the importance of a coordinated preclinical-to-clinical research continuum. Full article