PEEK: A Prodigious Material in Dentistry

Dr. Arpit Sikri, Dr. Jyotsana Sikri

(Part 1 - Stay tuned for Part 2 - Applications of PEEK in real life case scenarios)

ABSTRACT (1-5)

Polyetheretherketone (PEEK) is a vital dental material belonging to the family of polyaryletherketones (PAEKs). It is commonly categorized as “high-performance polymer”. The exceptional properties of PEEK has made this material “a wonder material” to be used for various applications not only in medicine but also in dentistry . In medicine, PEEK has been widely used in cardiology, orthopaedics and surgical procedures pertaining to maxillo-facial & spinal regions. In dentistry, PEEK has been used as the material of choice in field of restorative dentistry, orthodontics as well as implantology. This article reviews about PEEK as a material along with its multi-varied applications and various future perspectives in dentistry.

KEY WORDS: PEEK, polymer, PAEK, dental material, HPP, biomaterial, dental applications, thermoplastic polymer

Introduction

Polyether-ether-ketone (PEEK) is a specialized novel type of plastic, which is thermoplastic engineered. It has a wide variety of properties namely excellent mechanical, chemical and biological . The fundamental properties and advantages of PEEK polymer include:

1. Thermal properties i.e. higher thermal stability. The melting point (Tm) of PEEK is around 334–343°C with a glass transition temperature (Tg) of 143°C;
2. PEEK is known to have superb toughness and rigidity;
3. As far as creep is concerned, PEEK exhibits the best creep resistance out of all biomaterials;
4. A plethora of processing methods can be used for PEEK i.e. injection molding, additive manufacturing, subtractive manufacturing, compression molding, extrusion molding etc;
5. PEEK has amazing wear resistance properties. The incorporation of carbon fibres (CF), graphite and polytetrafluoroethylene (PTFE) furthermore improves the abrasion resistance of the same;
6. In addition to the abrasion resistance, the other important mechanical properties make use of inclusion of the carbon fibre (CF), glass fiber (GF) and barium sulfate (BaSO4), to meet various requirements;
7. Cytotoxicity – PEEK is particularly known for its biocompatibility and least cytotoxicity;
8. Stress shielding effect – PEEK is known to have elastic modulus closer to that of the human bone. This helps in prevention of stress shielding.
9. Sterilization compatibility – PEEK has been quite sterilization friendly. Even at higher temperatures kept for sterilization, it has unaltered properties.

Synthesis & Structure

PEEK is generally synthesized with the help of step-growth polymerization and is denoted as follows (Figure 1):

Properties

PEEK is known to exhibit excellent physical, mechanical, chemical and biological properties. The physical properties of PEEK are depicted in Figure 2.

The mechanical properties of PEEK are depicted in Figure 3.

The chemical properties of PEEK are depicted in Figure 4.

The biological properties of PEEK are depicted in Figure 5.