Biomaterials

Biomaterials

Vertebral Body Made of Titanium
© Fraunhofer IFAM Dresden
Vertebral Body Made of Titanium
X-ray Image Vertebral Body
© Fraunhofer IFAM Dresden
X-ray Image Vertebral Body

The use of new materials in medicine can open up new therapeutic options or reduce the risks of treatments and number of necessary surgeries. Fraunhofer IFAM Dresden develops new materials and manufacturing processes for biomedical products on the basis of powder metallurgical technologies.

Our research focuses on the structure and alloy development of new materials:

  • In orthopaedics, metallic implants with a cellular structure enable the elasticity and strength to be adapted to the bone
  • New powder metallurgical processes enable the production of materials with higher strength and improved corrosion properties or enable the production of near-net-shape geometries
  • For the application in biodegradable implants we develop new alloys based on magnesium and molybdenum for adapted corrosion rates and strengths

Applications

At Fraunhofer IFAM Dresden, materials and processes are developed primarily for the following applications:

Orthopaedics

© Fraunhofer IFAM Dresden
X-ray Defect Filling
Overview of Biodegradable Implant Materials
© Fraunhofer IFAM Dresden
Overview of Biodegradable Implant Materials

Large bone defects are still a medical problem. Such lesions have to be stably replaced until newly formed endogenous bone is able to take over the mechanical function independently again. Bone is mainly formed where it is biomechanically stimulated. Without physical pressure, however, there is a reduction in bone density - an effect which leads to bone degeneration when massive implants are used. Ideal implants should therefore be adapted to the mechanical properties of the bone.

 

Cellular implant materials made of titanium are highly resilient and at the same time as elastic as spongy bone. As a bone-like and waxable implant, they enable the replacement of large defects without the removal of the body's own bone. The aim of the development is to mobilize the patient more quickly and accelerate the healing process.

 

Another concept is being pursued with the development of biodegradable materials, where an ideal implant initially assumes full stabilization at the beginning of healing. With increasing bone regeneration, an increased load transfer to the bone is initiated by the resorption of the implant material. In this ideal case, an optimal adaptation to the respective strength condition is achieved at any time through progressive osteointegration on the one hand and decomposition of the implant on the other. Fraunhofer IFAM Dresden is therefore developing cellular implants based on magnesium.

Implants for Coronary Interventions

© Fraunhofer IFAM Dresden

In vascular surgery, cardiovascular implants based on metallic degradable materials reduce the risk of restenosis resulting from permanent implants as well as the risk of in-stent thrombosis due to the presence of drug-eluting stents. Such degradable vascular implants also open up new treatment options in pediatrics.

Fraunhofer IFAM Dresden develops new powder metallurgical technologies and materials with which corrosion rates can be adapted through ultra-fine structures or advanced alloys.

Implants for Maxillofacial Applications

Example of a Magnesium Implant in Oral Surgery (Model)
© Fraunhofer IFAM Dresden
Example of a Magnesium Implant in Oral Surgery (Model)
Model of a Skull Cap Implant
© Fraunhofer IFAM Dresden
Model of a Skull Cap Implant

Defects of the skull calotte and midface usually require patient-specific implant materials. For this purpose, the OsteoPAKT project (funded by the BMBF) is developing implant materials with a novel treatment approach for individual, patient-specific bone replacement implants, especially in the cranial and facial region, with which functionally high-quality results can be achieved. At the same time a faster supply of the patient is made possible and a cost-effective treatment is realized, because by providing the individual implant within 48 hours multiple operations can be avoided.

Using modern imaging, a digital model of the defect area is created. This model is used for the production of a negative stencil through 3D printing. This patient-specific three-dimensional template is used to shape the prefabricated composite material consisting of a titanium sponge and a bone cement paste. After the bone cement has almost completely dried and has been sterilized, the implantation procedure can be performed.

The ResorbM project (funded by the BMBF) is examining whether resorbable implants for the surgical treatment of craniosynostoses in infants and toddlers can be manufactured from molybdenum. On the one hand, the metal has a high mechanical strength, on the other hand, its resorbability makes further surgery to remove the implant unnecessary. This makes the procedure much easier for children to cope with. Since the handling of molybdenum implants will be similar to that of titanium implants, they will be seamlessly integrated into existing treatment processes and workflows in clinics. This should raise the quality of care in cranio-maxillofacial surgery for small children worldwide to a significantly higher level.

Materials for Dental Implants

Model of a Dental Implant Containing Ceramill Sintron®
© Fraunhofer IFAM Dresden
Model of a Dental Implant Containing Ceramill Sintron®

Ceramill Sintron® by AmannGirrbach revolutionizes the CNC-based dry machining of non-precious metal restorations with desktop milling machines in our own laboratory. Due to the "wax-like" nature of Ceramill Sintron®, the material can be milled dry without difficulty. During the subsequent sintering process in an inert gas atmosphere, the frameworks achieve their final material properties - a CoCr unit with a very homogeneous material structure. The subsequent veneering can be carried out using any conventional CoCr framework ceramic. Ceramill Sintron® was developed in cooperation with Fraunhofer IFAM Dresden.

Materials

Open-Cell Foam Structure
© Fraunhofer IFAM Dresden
Open-Cell Foam Structure
Titanium Powder
© Fraunhofer IFAM Dresden
Titanium Powder
  • Titanium and titanium alloys for the use in permanent implants in orthopaedics and as a material for dental prostheses
    high strength, good biocompatibility, low corrosion, high osteoconductivity, high market acceptance
  • Tantalum for the use in permanent implants in orthopaedics
    good biocompatibility, low corrosion, already introduced to the market
  • CoCr alloys for the use in the dental sector or joint endoprostheses
    high strength, good biocompatibility, low corrosion, good tribological properties, high market acceptance
  • Stainless steels for the use in temporary implants
    gute Biokompatibilität, geringe Korrosion, bereits in den Markt eingeführt, deutlich geringere Knochenadhäsion als Titan
  • Magnesium and magnesium alloys
    complete degradation, short degradation times, very high biocompatibility, high osteoconductivity
  • Molybdenum and molybdenum alloys
    high strength, very high stiffness, long degradation rates

Technologies

View into the Spark-Plasma-Sintering Plant
© Fraunhofer IFAM Dresden
View into the Spark-Plasma-Sintering Plant
Melt Spinning for the Fabrication of Powders with Nanocrystalline Structure
© Fraunhofer IFAM Dresden
Melt Spinning for the Fabrication of Powders with Nanocrystalline Structure
  • Development of cellular metallic materials for stiffness-adapted orthopaedic implants with high osteointegration capability
  • Rapidly solidified magnesium alloys with highly reduced corrosion rates and improved mechanical properties
  • Spark plasma sintering - Sintering technology for high strength and adapted corrosion rates
  • Fibre metallurgy combines the advantages of rapidly solidified alloys with the favourable properties of cellular metals
  • Sintering technology
  • Melt-spinning – Ultra fine-grained / amorphous materials with increased mechanical strength and corrosion resistance
  • High energy grinding
  • Structural analysis
  • Elementary analysis