3D bioprinting of collagen-based materials for oral medicine

Oral diseases have emerged as one of the leading public health challenges globally.Although the existing clinical modalities for restoration of dental tissue loss and cra niomaxillofacial inju ries can achieve satisfactory therapeutic results,they cannot fully restore the original complex anatomical structure and physiological function of the tissue.3D printing of biological tissues has gained growing interest in the field of oral medicine with the ability to control the bioink component and printing structure for spatially heterogeneous repairing constructs,holding enormous promise for the precise treatment of oral disease.Particularly,collagen-based materials have been recognized as promising biogenic bioinks for the regeneration of several tissues with high cell-activating and biocompatible properties.In this review,we summarize 3D printing methods for collagen-based biomaterials and their mechanisms.Additionally,we highlight the animal sources of collagen and their characteristics,as well as the methods of collagen extraction.Furthermore,this review provides an overview of the 3D bioprinting technology for the regeneration of the pulpal nerve and blood vessels,cartilage,and periodontal tissue.We envision that this technique opens up immense opportunities over the conventional ones,with high replicability and customized function,which can ultimately promote effective oral tissue regeneration.