Design and additive manufacturing of root analogue dental implants: A comprehensive review

Abstract

Dental implants are key components in treating dental diseases and correcting dental defects, and they have gained widespread utilisation in various medical operations. However, traditional screw thread implants have been associated with certain drawbacks, including issues such as poor consistency with the alveolar bone and difficulty in customisation. Root analogue implants (RAI) are considered a promising substitute; however, they are not widely applied until now as their geometry design needs more improvements. The utilisation of porous structures, such as triply periodic minimal surfaces, in dental implants can reduce the elastic modulus, increase interconnectivity, and allow for strictly controllable structural characteristics. To achieve optimal initial and long-term stability, it is essential to have a moderate geometry that promotes a proper fit between the dental implants and the natural bone. Different porous and macro-retention structures of RAIs have been investigated due to the above two demands. However, owing to their complex porosity, such structures can only be effectively manufactured using additive manufacturing techniques. Various additive manufacturing technologies have been employed for the fabrication of dental implants and have provided good surface quality and mechanical properties. In vivo tests have demonstrated that their performance is similar to that of commercial implants fabricated using subtractive manufacturing techniques. In this review, we comprehensively examine the design concepts and processes involved in the development of dental implants, along with the application of additive manufacturing methods for their fabrication, while also offering recommendations for the future advancement of dental implant designs.