Novel Method for the Production of Titanium Foams to Reduce Stress Shielding in Implants

Abstract

Titanium foams have potential applications in orthopedic and dental implants because of their low elastic modulus and good bone in-growth properties. In the present study, a novel method for the preparation of three-dimensional interconnected microporous titanium foams has been developed. This method is based on the insertion of a filler metal into the titanium metal by arc melting, followed by its removal by an electrochemical dealloying process for the development of foams. Complete removal of the filler metal by the electrochemical dealloying process was confirmed by an X-ray diffractometry (XRD) analysis, whereas scanning electron microscopy (SEM) analysis of the developed foams showed the development of interconnected porosity. Ti foams with different levels of porosities were successfully developed by varying the amount of the filler metal. Mechanical and thermal characterizations of the developed foams were carried out using compression testing and laser flash apparatus, respectively. The yield strength and elastic modulus of the developed foams were found to decrease by increasing the volume fraction of pores. The elastic modulus of the developed titanium foams (15.5–36 GPa) was found to be closer to that of human bones, whereas their yield strength (147–170 MPa) remained higher than that of human bones. It is therefore believed that the developed Ti foams can help in reducing the problem of stress shielding observed in orthopedic implants. The thermal diffusivity of the developed foams (4.3–0.69 mm2/s) was found to be very close to that of human dentine.

Biomechanical Investigation of Patient-Specific Porous Dental Implants: A Finite Element Study

“…To overcome these challenges, researchers are continuously exploring innovative strategies to minimize the risk of stress shielding and improve the longevity and success of implants [12,13]. One potential solution is the use of materials with lower Young's modulus, such as porous Ti, which could provide a better match with the bone and reduce the risk of implant failure [14,15].…”

Evaluation of Selective Laser Melted Ti6Al4V/ST316L Composite and Selective Laser Sintered Polyamide 12 Implants for Orthopedic Applications: Finite Element Analysis, Physical and Mechanical Characterization, in Vitro and in Vivo Biocompatibility

“…Von Mises stresses for all implants were below the bulk material's yield strength. The implant remains stable within the body even when loaded [25]. Human cortical bone's yield strength was not exceeded by maximum von Mises stresses in femur and tibia [26].…”

“…Prior to cells sticking to biomaterial surfaces, proteins get absorbed from body fluids, controlling subsequent cell adhesion and behavior. This is predictable as surface roughness is known to encourage protein absorption [25]. Given that protein absorption on surfaces aids in cell proliferation and osteogenic differentiation [26], enhanced cell proliferation and osteogenic activity on surfaces are linked with improved protein absorption, which is an outcome of a rough surface topography.…”

Influence of Ultrasound on the Characteristics of CaP Coatings Generated Via the Micro-arc Oxidation Process in Relation to Biomedical Engineering

“…It exhibits many remarkable properties, such as excellent biocompatibility, high specific strength, good fatigue resistance, high chemical stability in the complex environment of human body fluids, good corrosion resistance in the aggressive chemical environment of the human body, and low allergenicity. , However, despite being relatively well developed, the implantology of Ti materials still faces difficulties, such as inadequate mechanical properties and lack of osteogenic activity. − Those problems contribute to implant surgery failures, which may result from metallosis or stress shielding. Consequently, implant loosening may be due to insufficient bone integration and/or fibrous tissue production. − …”

“…Consequently, implant loosening may be due to insufficient bone integration and/or fibrous tissue production. 10 − 13 …”