Arif Gök

Bu bölüm, biyomalzemelerin temel prensiplerini biyomekanik bakış açısıyla ele alarak malzeme bilimi ile biyomedikal uygulamalar arasındaki ilişkiyi kapsamlı biçimde açıklamaktadır. İlk olarak biyomalzeme kavramı, biyouyumluluk ve biyomalzeme doku etkileşimleri tanıtılmakta; ardından malzemelerin atomik yapısı, mekanik özellikleri, elastik ve plastik davranışları biyomedikal uygulamalar bağlamında değerlendirilmektedir. Bölümde biyolojik dokuların viskoelastik özellikleri, biyotriboloji, aşınma mekanizmaları ve implant performansını etkileyen biyomekanik süreçler ayrıntılı olarak incelenmektedir. Ayrıca biyouyumluluk, toksisite, biyomalzeme sınıfları, ortopedik ve dental implantlar, kardiyovasküler sistemler, doku mühendisliği ve kontrollü ilaç salım uygulamalarında kullanılan biyomalzemeler güncel bilgiler ışığında ele alınmaktadır. Son bölümde ise akıllı biyomalzemeler ve gelişmiş biyomalzeme teknolojilerinin gelecekteki biyomedikal uygulamalardaki rolü değerlendirilmektedir. Bölüm, biyomalzeme bilimine giriş niteliğinde kapsamlı bir kaynak sunarken, mühendislik, biyoloji ve sağlık bilimleri arasındaki disiplinler arası yaklaşımı da vurgulamaktadır. This chapter presents a comprehensive introduction to biomaterials from a biomechanical perspective, highlighting the relationship between material science and biomedical applications. It introduces the fundamental concepts of biomaterials, biocompatibility, and biomaterial–tissue interactions before discussing atomic structure, material classification, and the mechanical behavior of biomaterials under physiological conditions. The chapter examines elastic and plastic deformation, viscoelastic properties of biological tissues, and tribological mechanisms that influence implant performance and long term clinical outcomes. It further explores the biological responses to implanted materials, including biocompatibility, toxicity, and host tissue interactions. Major classes of biomaterials including metals, polymers, ceramics, natural materials, and composites are reviewed together with their applications in orthopedics, dentistry, cardiovascular devices, tissue engineering, and controlled drug delivery systems. The final section focuses on smart and advanced biomaterials, emphasizing emerging technologies designed to improve tissue integration, mechanical compatibility, and regenerative performance. By integrating principles of biomechanics, materials engineering, and biomedical science, this chapter provides readers with a solid foundation for understanding the design, characterization, and clinical applications of modern biomaterials.

Background/Objectives: The medial meniscus is crucial for load transmission and knee stability. Meniscal tears disrupt joint biomechanics, increasing the risk of cartilage degeneration. However, few studies have quantitatively compared how different tear types affect stress and contact mechanics using finite element analysis (FEA). This study aims to analyze stress distributions for various meniscal tear types and develop a predictive model for meniscal stress behavior. This study investigates how stress distributions differ between healthy and torn medial menisci under identical loading conditions. The study examines which meniscal tear type produces the highest stress concentrations. The effects of different tear types on penetration, gap formation, pressure distribution, and sliding distance at the meniscus interface are also analysed. Materials and Methods: The FEA model of the knee joint, including femoral and tibial cartilage and the medial meniscus, was developed. Simulations were conducted for a healthy meniscus and for menisci with radial, horizontal and complex tears. Stress, penetration, gap, pressure, and sliding distance were calculated, and a mathematical model describing their relationships was established. Results: All torn menisci exhibited significantly higher stresses than the healthy meniscus (p < 0.001). Radial tears generated the highest stress concentrations (p < 0.001). Pressure was mainly influenced by meniscal geometry, while the gap remained nearly constant. Penetration increased slightly (p < 0.05). The predictive model demonstrated a strong correlation between meniscal stress and interface parameters (R² > 0.9). In a healthy meniscus, stress distribution is homogeneous (≈26 MPa). Stress concentration increases depending on the tear type: limited in a horizontal tear (≈26.5 MPa), significant in a vertical tear (≈30.8 MPa), and highest in a radial tear (≈40.6 MPa). These results indicate that as the tear progresses, the load-bearing capacity of the meniscus decreases, and stresses concentrate at the tear edges. Conclusions: Meniscal tears, especially radial ones, substantially alter knee biomechanics and elevate tissue stress. These biomechanical insights highlight the importance of early diagnosis and targeted rehabilitation strategies to prevent further cartilage damage and osteoarthritis progression.

In this study, the biomechanical performance of four different coating materials applied on 316L stainless steel Schanz screws used in the treatment of intertrochanteric fractures (ITF) was examined by finite element analysis (FEA). Coatings: hydroxyapatite (hA), hexagonal boron nitride (hBN), zirconium dioxide (ZrO ₂ ), and aluminum oxide (Al ₂ O ₃ ). How these coatings affect the mechanical properties, durability, and biocompatibility of screws reveals the potential to increase the effectiveness of external fixators. Analyses aim to make recommendations for safer and more effective applications during the treatment process by examining the effects of each coating on stress distribution, deformation and stress parameters. Ultimately, the most suitable material selection for fracture healing depends on clinical needs and the patient's condition. If high stress transmission is required, 316L or 316L‐hA may be preferred. If more stable and low shear performance is desired, 316L‐ZrO ₂ or 316L‐Al ₂ O ₃ coatings might be considered. In any case, it is essential to take all parameters into account when choosing the material.

This study evaluates the biomechanical performance of Ti6Al-4 V and 316L stainless steel (SS) screws for femoral neck fracture fixation. The microstructural analysis scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS) was conducted to examine material composition. X-ray diffraction patterns of Ti6Al4 V and AISI 316L materials were added for identifying crystallographic phases. Simulation results revealed significant differences when comparing Ti6Al4V and 316L screw materials. For Ti6Al4V screws, the von Mises stress in the screw body was 204.56 MPa, and the stress above the fracture line was 124.57 MPa. In contrast, for 316L stainless steel screws, the stress within the body increased to 236.33 MPa, while the stress at the fracture line decreased to 109.65 MPa. Examining deformation-related parameters, the gap value for Ti6Al4V screws was 0.065 mm, penetration value was 0.0036 mm, sliding distance was 0.109 mm, and total deformation was 2.4625 mm. For 316L screws, these values are 0.054 mm, 0.0032 mm, 0.091 mm, and 2.4634 mm, respectively. While 316L offers better initial mechanical stability, Ti6Al4 V remains favorable for long-term use due to superior corrosion resistance and biocompatibility. Despite widespread use of Ti6Al4 V and 316L SS in femoral neck fracture fixation, comparative data on their biomechanical performance and corrosion behavior under torsional loading remain limited. This study focuses on these two clinically relevant materials, evaluating their mechanical behavior and corrosion susceptibility. Finite-element analysis was performed to simulate torsional stress, while SEM and EDS analyses examined microstructural characteristics influencing performance. The results showed nearly identical deformation for both materials, with 316L exhibiting higher screw stress but lower stress at the fracture line, leading to reduced micromotions. Ti6Al4 V offered superior corrosion resistance and long-term biocompatibility. These findings provide quantitative insights for implant selection, supporting designs that balance immediate mechanical stability with favorable long-term material performance. Further research is needed to identify the most effective implant design and material selection to balance immediate fixation and support desirable bone regeneration.

This study investigates an alternative surgical approach for repairing meniscal root tears, a common knee injury that can significantly impact joint stability and function. Traditional repair methods often face challenges such as high rates of retear and persistent pain. To address these limitations, this research utilizes finite element analysis (FEA) to compare the biomechanical performance of an alternative technique against established surgical procedures. FEA models were carefully constructed to accurately represent the complex anatomy of the knee joint, including the medial meniscus, cartilage, ligaments, and surrounding bone structures. These models were then subjected to various loading conditions that simulated physiological activities such as walking, running, and squatting to assess the stress and strain experienced by the repaired tissue under realistic conditions. The results of the FEA simulations demonstrated a significant reduction in stress and strain on the repaired medial meniscus root when the alternative technique was employed compared to traditional methods. This reduction in biomechanical load is crucial for promoting tissue healing and minimizing the risk of retear. By reducing excessive stress on the repair site, the alternative surgical technique may enhance long‐term patient outcomes, potentially improving knee function, reducing pain, and decreasing the likelihood of further surgical interventions such as meniscectomy or knee prosthesis replacement. In conclusion, this study provides strong evidence for the potential benefits of the alternative surgical technique in repairing meniscal root tears. The findings suggest that this approach may offer a promising alternative to traditional methods by optimizing biomechanical stability and promoting more favorable healing conditions. Further clinical studies are warranted to validate these findings and translate these promising results into improved patient care.

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This study investigates the biomechanical behavior and corrosion resistance of Ti6Al4V screws coated with hexagonal boron nitride (hBN) and hydroxyapatite (HA) for femoral neck fracture fixation using a triangular configuration under axial loading. Utilizing 3D modeling software (Geomagic Studio and SolidWorks) and numerical analysis with AnsysWorkbench, the screws were designed and analyzed. The study aimed to determine the biomechanical effects and corrosion relationships of Ti6Al4V coated with hBN and HA. Comparative analysis revealed that Ti6Al4V-HA exhibited higher gap (0.036427), penetration (0.0028631), and sliding distance values (0.0024398) compared to Ti6Al4V-hBN (gap: 0.036196, penetration: 0.0028579, sliding distance: 0.0024300), indicating greater reactivity and corrosion potential. Conversely, Ti6Al4V-hBN demonstrated superior corrosion resistance. The findings suggest that hBN-coated Ti6Al4V screws provide improved stability and reduced stress concentration, which are critical for successful fracture fixation. Additionally, hBN coating effectively reduced the corrosion rate of Ti6Al4V in simulated body fluids, enhancing implant longevity and patient safety. However, further in vivo studies are necessary to validate these findings and assess long-term performance and biocompatibility. The study underscores the need to consider multiple factors in implant material selection to gain a comprehensive understanding of corrosion behavior. Overall, this research lays the groundwork for future advancements in orthopedic implant technology and has the potential to improve patient outcomes in fracture management.