the evolution of Polymers such as PEEK Optima or BioHPP especially for the dental industry has lead to an increase of applications of the material. Due to the fact that worldwide thousands of dental implants are placed every day the dental community is very interested in new materials which can improve and simplify the sometimes very complex and expensive process of restoring these implants with crowns, bridges and dentures.
Firstly: what is PEEK?
PEEK stands for Polyether ether ketone and is a colourless organic thermoplastic material with excellent mechanical and chemical resistance properties.
This material is being used for medical applications such as spine implants for many years and is currently becoming more and more popular in dental laboratories and dental practices.
But this material is everything but new considering that the origins of these materials date back to 1977 when Chemists (Rose and his team) at Imperial Chemical Industries started to construct polymers based on principles developed in the 1930’s. One of their first products was the aromatic polyether ketone family and the first variation of the theme of this family was the polymer polyether ether ketone B which is now simply known as PEEK.
Metal in comparison has several disadvantages when used in medical and / or dental applications:
higher stiffness compared with bone
possible release of metal ions (Galvanic element)
can cause artefacts in CT and MRI Scans
similar elasticity as bone
low moisture absorption
Thus far, PEEK has had the greatest clinical impact within the field of spine and orthopaedic implants but recently new versions of PEEK for dental applications have been developed.
The addition of Carbon Fibres enhances the mechanical properties of the original material with an increase of stiffness, strength and creep resistance.
PEEK Optima is currently used in dentistry for temporary Abutments, healing caps, telescopic attachments, precision attachments and Implant-supported superstructures. With CAD-CAM technology PEEK “blanks” can be used to mill frameworks for dentures or bridges within minutes.
Another Variant of PEEK is BioHPP developed by Bredent GmbH. BioHPP stands for Bio High Performance Polymer and has been developed especially for dental applications.
The modification of the material consists of an addition of a special ceramic filler with a grain size between 0.3 to 0.5 μm. According to the manufacturer the small grain size results in a constant homogeneity. Also the small filler size leads to extremely good polishing properties.
Implants are osseointegrated without the formation of a periodontal ligament compared with a natural tooth. Conventional materials such as metal and zirconium have very little elasticity which can lead to fractures of the porcelain or TMJ problems. Allergies and corrosion are also disadvantages of these materials.
Therefore it is the cushion effect of PEEK which makes it a desirable material for implant bridges and crowns.
Denture framework are conventionally made from Chrome-Cobalt. BioHPP can be a viable alternative to Chrome-Cobalt as it is lighter, does not cause any galvanic elements (corrosion) when in contact with other metals in the mouth.