[Potential of three-dimensional bioprinting in oral soft tissue engineering applications]

Oral soft tissue engineering involves the reconstruction or restoration of oral and maxillofacial functions and esthetics. As an emerging technology from the early 21st century, three-dimensional (3D) bioprinting promises great application potentials in the preparation of scaffolds and engineered tissues/organs. Although oral soft tissues include dental pulp, periodontal ligament, gum, oral mucosa, and salivary glands as well as related maxillofacial skin, vascular, muscular, and neuronal tissues, the current application of 3D bioprinting in oral soft tissue-restoration is mainly limited to dental pulp-regeneration. Different bioinks are used to load dental pulp cells into the dentin matrix for restoring the dental pulp tissue; 3D bioprinting has only been reported in a few in vitro studies on periodontal ligament-reconstruction and salivary gland culture; and 3D bioprinting used towards regenerating gingival tissue/oral mucosa has not been demonstrated. The limited application of 3D bioprinting in oral soft tissue engineering is perhaps related to the complex, fine, and orderly structure of the periodontal ligament, the moist environment of the oral cavity, the small operating space, and the continuous chewing pressure. The studies on bioprinting of skin, vascular, muscular, and neuronal tissues are broad, but they are typically not oral-specific. This article introduces the current application status and prospects of 3D bioprinting in the regeneration of oral soft tissues, using cytocompatible hydrogels as bioinks.