4D Printing in Prosthodontics: A Literature Review

Abstract

Four-dimensional (4D) printing represents an emerging advancement in additive manufacturing that combines three-dimensional printing with smart, stimuli-responsive materials capable of undergoing programmed changes in shape, dimensions, physical properties, or biological function over time. Unlike conventional 3D-printed prostheses, which remain largely static after fabrication, 4D-printed structures are designed to respond to stimuli such as temperature, moisture, pH, light, magnetic fields, or electrical signals. This literature review discusses the fundamental principles, materials, fabrication technologies, potential applications, current limitations, and future prospects of 4D printing in prosthodontics. Shape-memory polymers, hydrogels, shape-memory alloys, elastomers, and multifunctional composites form the principal material systems currently being investigated. Potential prosthodontic applications include self-adapting complete dentures, responsive removable partial denture components, adaptive fixed and implant prostheses, shape-memory obturators, dynamic maxillofacial prostheses, smart antimicrobial devices, controlled drug-delivery systems, self-healing materials, and regenerative scaffolds. Although the underlying material science and biomedical applications have progressed considerably, direct evidence supporting clinically functional 4D-printed prostheses remains limited, with most prosthodontic applications still experimental or conceptual. Challenges involving mechanical strength, fatigue resistance, transformation accuracy, biocompatibility, reproducibility, sterilization, and regulatory approval must be addressed before routine clinical translation. Future integration with digital scanning, biosensors, artificial intelligence, digital twins, and tissue engineering may facilitate the transition from static patient-specific prostheses toward adaptive, responsive, and therapeutic prosthetic systems.