3D printing in orthodontics: current clinical applications, challenges, and future directions

Three-dimensional (3D) printing has become an important component of digital orthodontics and has expanded its role from model fabrication to the production of a wide range of customized appliances. This review summarizes the current clinical applications of 3D printing in orthodontics, including diagnostic models, indirect bonding trays, customized brackets, clear aligners and retainers, as well as other adjunctive devices such as miniscrew guides, space maintainers, and expanders. In addition, emerging applications such as smart materials and 4D printing are briefly discussed. Current evidence indicates that 3D printing has improved workflow efficiency, appliance customization, and manufacturing flexibility in orthodontic practice. However, the level of clinical evidence remains uneven across different applications. While some uses, such as model fabrication and indirect bonding trays, have become relatively well established, others, particularly direct-printed aligners and advanced functional appliances, are still in the early stages of clinical translation. Important challenges remain in terms of printing accuracy, material durability, esthetic stability, biocompatibility, post-processing protocols, and long-term clinical validation. Overall, 3D printing is reshaping orthodontic workflows and offers significant potential for personalized treatment, but broader clinical adoption will depend on stronger evidence, improved material performance, and more standardized manufacturing protocols.