A Review on Current Trends of Polymers in Orthodontics: BPA-Free and Smart Materials

Polymeric materials have always established an edge over other classes of materials due to their potential applications in various fields of biomedical engineering. Orthodontics is an emerging field in which polymers have attracted the enormous attention of researchers. In particular, thermoplastic materials have a great future utility in orthodontics, both as aligners and as retainer appliances. In recent years, the use of polycarbonate brackets and base monomers bisphenol A glycerolate dimethacrylate (bis-GMA) has been associated with the potential release of bisphenol A (BPA) in the oral environment. BPA is a toxic compound that acts as an endocrine disruptor that can affect human health. Therefore, there is a continuous search for non-BPA materials with satisfactory mechanical properties and an esthetic appearance as an alternative to polycarbonate brackets and conventional bis-GMA compounds. This study aims to review the recent developments of BPA-free monomers in the application of resin dental composites and adhesives. The most promising polymeric smart materials are also discussed for their relevance to future orthodontic applications.