The aligner market has experienced significant growth due to the increasing demand for aesthetic orthodontics. Clear aligners(CA) are removable, can gradually move teeth into their predetermined positions, and are custom-made based on patient-specific malocclusion configurations, providing additional benefits. However, it is important to note that not all aligners are created equal, as the ones currently available vary in construction materials, thickness, and clinical protocols. The efficiency of CA can be influenced by multiple factors. Aligners are dental appliances that are worn for 22 hours a day, fitting over the teeth and the edge of the gums. Throughout the treatment period, new aligners are provided on a regular basis until the end of the therapy, which can take anywhere from 6 months to 2 years. It is important to note that the oral environment may change during treatment, which can affect the plastic materials used in the aligners. The transparent thermoplastic materials(TM) used to create CA for orthodontic therapy have the required mechanical, chemical, and physical properties. The mechanical properties of the polymers used significantly affect the efficacy of the treatment. The ideal polymers for aligners exhibit low stiffness, excellent deformability, dimensional and environmental stability, and great biocompatibility. This comprehensive study aims to cover the various materials used in the production of CA and to explain the critical qualities of these materials that contribute to their effectiveness in an oral environment.