Thermoplastic Materials for Infrastructures in Prosthodontic Rehabilitation: A Review

Abstract

Conventionally, chromium-cobalt (Cr-Co) and titanium (Ti) alloys represent the most common metallic materials used in oral rehabilitation. However, due to esthetic concerns and adverse effects in oral tissues (eg. galvanism and allergic reactions), the development of metal-free infrastructures has been an expanding research area in Prosthodontics. In this context, a range of thermoplastic polymers such as polymethylmethacrylate (PMMA), polyamide, polycarbonate, acetal resin or polyoxymethylene (POM), polyether ether ketone (PEEK) and polyether ketone ketone (PEKK), has attracted attention for its versatility and mechanical properties. This article aims to present a literature review of the thermoplastic polymers most frequently used for prosthetic infrastructures, outlining their properties, advantages and disadvantages. Article search was conducted in PubMed, Scopus and Google Scholar databases, including articles published from 2008 to 2018, written in English and Portuguese, selected according to their abstracts and relevance to the theme. The properties and applications of each polymeric material were explored individually, establishing comparisons whenever appropriate. Overall, each material has diverse clinical applications in the oral rehabilitation field. Thermoplastic material selection and design should be performed upon a complete study of the properties and limitations of each polymer, using a case-by-case approach. Although more studies are necessary to fully characterize their spectrum of applications, PEEK and PEKK appear as promising candidates for the production of prosthetic infrastructures.