Materials Used In Medical Implants

Medical implants are tightly regulated by the FDA, and they can only be manufactured from biomaterials that have a proven safety record. This includes several polymers and high performance polymers like PEEK. PEEK is of particular interest to medicine as it has emerged as a frontline biomaterial for a diverse range of applications.

Other polymers used in medical implants include:

  • Polyurethane
  • Polyglycolide (PGA)
  • Polytetrafluoroethylene (PTFE)
  • Polyethylene (PE)

Non-polymer biomaterials are also prominent in medicine and include:

  • Titanium
  • Ceramics
  • Chromium
  • Cobalt

There are several more, but these are the most common biomaterial options.

What medical implants are PEEK used in?

PEEK is a notable biomaterial for its material properties and for its superb processability. As a high performance thermoplastic, PEEK is converted into medical components at high temperatures and using one of several methods. Those methods include injection molding, machining and extrusion, which is particularly useful for creating long segments of medical tubing.

Some of PEEK’s other primary medical applications include:

  • Interbody fusion cages – PEEK was first used in spinal fusion procedures, and it’s now a frontline option for interbody fusion cages. As interbody fusion cages represent an industry worth more than $1 billion, according to industry numbers, PEEK is a valuable biomaterial due to its role in spinal fusion alone.An active area of medical engineering research is making a better PEEK interbody fusion cage. The returns on this research are promising, as the current generation of fusion cages demonstrate better bone-in growth. This is due to superior design features like microporous structures and the use of materials like hydroxyapatite or zeolite.
  • Trauma fixation devices – PEEK has been manufactured into an array of trauma fixation components, including hardware and bone plates. PEEK’s excellent pullout strength and resilience makes it ideal in this role, especially when PEEK is augmented with chopped carbon. Termed CFR PEEK, this polymer grade offers added stiffness and strength and fatigue resistance over unfilled PEEK.
  • Joint replacement devices – Joint replacement systems must withstand a great deal of compressive forces while retaining their shape and position. PEEK is well-suited to these challenges, which is why it can be incorporated into knee and hip replacement procedures. PEEK has a good potential as an effective biomaterial for acetabular cups, in particular, as its wear resistance means it can function long term as a weight-bearing material.
  • Cardiovascular tubing and devices – PEEK is an extremely popular option for cardiovascular tubing, for several reasons. PEEK possesses excellent torsion resistance (the highest among polymer biomaterials), so it can weather the constant push and pull of the vascular network. PEEK also has a low coefficient of friction, so it offers a strong mix of pushability and navigation. In other words, PEEK can be inserted into the vascular network without the need for a lot of force, and it can move through nonlinear vascular segments with ease.PEEK’s processability and machinability means it can be converted into very small components without compromising its material properties. As cardiovascular devices can be inconceivably tiny, PEEK has an advantage in this area.

    Cardiovascular tubing is a commonplace PEEK application, and it has been incorporated into various device delivery systems, including valve replacement and stent placement. PEEK is also used in ablation catheters and auto defibrillators, where its electrical insulating capabilities are important.

  • Dental devices and implants – PEEK is quickly gaining attention in dentistry, and it’s already being used in partial dentures and in dental implants. Dental implants rely on a material that can readily fuse with bone, and PEEK does so better than most biomaterials.For partial dentures, it’s PEEK’s aesthetics and machinability that make it an attractive choice. Patients want their dentures to look natural and blend in with surrounding dental tissues. Patient comfort is also an important consideration, and a snug fit is what’s needed to ensure it. PEEK excels here again, as it can be precisely color matched to produce a natural look, to the point where it would be highly difficult for anyone to notice the difference. Since PEEK can be machined to precise tolerances, it is a perfect material for something as individual as a patient’s teeth and gums. Many practices now rely on computer-aided design and manufacturing, along with 3D imaging of the patient’s mouth, to create dental devices that fit perfectly.

    Furthermore, PEEK does not alter the patient’s taste and it does not trap heat or provoke an allergic response.

PEEK’s durability, processability and machinability has made it one of the most versatile biomaterials in existence. Engineers and device manufacturers are working hard to create better medical devices out of PEEK, providing better outcomes for patients.