The use of vacuformed retainers (VFRs) for orthodontic retention is a common practice, making it important to evaluate the physical properties of these thermoplastic materials to determine their longevity. Research indicates that VFRs can exhibit significant wear over time, with noticeable differences in performance among various thermoplastic materials. Previous studies have shown that polyethylene copolymers (PEC) offer superior wear resistance compared to polypropylene copolymers (PPC). This study aims to evaluate the in vitro wear resistance of different thermoplastic materials, including polypropylene copolymers (PPC), polyethylene copolymers (PEC), and polyvinyl chloride polymers (PVC).