One of the main research areas of the materials science team at the Polyclinic for Dental Prosthetics at the LMU Munich is polyaryl ether ketone (PAEK) materials. This article provides a brief, current overview of the materials.
The material group of polyaryl ether ketones (PAEK) is classified as a high-performance thermoplastic, which has recently been gaining interest as a restorative material in dentistry. PAEK materials are semi-crystalline polymers. They are characterized by high mechanical and good chemical properties and are free of residual monomers. Due to their biocompatibility, PAEK materials are considered an excellent alternative to metallic restorations.
Classification of materials
Polyetheretherketone (PEEK) is currently the best-known representative of PAEK materials in dentistry. In addition to PEEK, there are other material modifications. These differ in the variation of the functional groups in the polymer chain. This allows the properties of the material to be changed and adjusted as desired. So PAEK is not the same as PAEK. In comparison to PEEK, polyether ketone ketone (PEKK) is made up of only one ether and two ketone groups. This makes the polymer slightly stiffer, but the optical and chemical properties remain very similar. There are numerous indication areas for both modifications, e.g. E.g. crown and bridge frameworks, denture bases and brackets, implant abutments and telescopes.
Material variants: what is what?
PEEK is offered by various manufacturers in different qualities. In order to optimize the originally greyish-opaque color for use in dentistry, titanium oxides (TiO2) were used as filler particles. These also have a positive effect on the mechanical properties. Unfilled (pure) PEEK is primarily used for removable dentures. Filled materials can also be used for fixed restorations. In addition to pure PEEK materials, materials with a TiO2 filler content of 20 to 30% by weight are currently used. The color of the products varies from gray to pearl white to light yellow. Pink materials are now available for the gingival parts.
P.E.K.K. However, it is currently only offered by one manufacturer, Cendres+Métaux SA with the product Pekkton ivory. To optimize the mechanical properties, the material is also filled with TiO2. Pekkton ivory contains around 10% TiO2 by weight and is visually characterized by a slightly grayish character. The material is adapted to various indications in terms of ductility and varies in the ratio of crystalline and amorphous components.
application
In order to be able to process PAEK materials in as many different ways as possible, PEEK and PEKK are available in different dosage forms. Prefabricated discs enable the CAD/CAM-supported production of restorations. The material can be processed as granules or pellets of different sizes in appropriate press ovens. It should be noted that pressing the materials affects the mechanical properties and leads to increasing ductility.
Product variety
PAEK materials in different colors for pressing and CAD/CAM technology
The first PAEK materials were developed in 1978. They have been commercially available since 1998. The bredent group has long-standing expertise in PAEK-based materials in dentistry. In 2006, the first PEEK-based material, BioXS (processing: Thermopress system), was brought onto the market. The material was further developed and replaced by BioHPP (processing: for2012press system) in 2. In 2011, nt-trading brought Dentokeep, the first PEEK-based blanks (processing: CAD/CAM) for permanent dentures onto the market. In 2013, bredent followed suit with breCAM BioHPP, Zirkonzahn with Tecno Med and Tecno Med Mineral and in 2014 Merz Dental with PEEK BioSolution. PAEK materials are now sold as blanks by many companies. The company Juvora has been offering the PEEK-based material innoBlanc medical PEEK from Invibio Biomaterial Solution (ten years of experience with human implants) as a CAD/CAM blank since 2012. These blanks are now also sold by Siladent, Teamziereis and Schütz Dental.
Note: The PAEK material range is expanding every day. We therefore make no claim to completeness or up-to-dateness. The research was carried out to the best of our knowledge and belief.
Author: A. Kieschnick, Berlin (www.annettkieschnick.de)