Technological watch

Additive manufacturing has transformed the perspective of producing 3D objects towards achieving high quality in terms of accuracy, resolution, and high mechanical integrity with excellent surface finishing in little time compared to subtractive (traditional) production. Vat photopolymerization (VPP) additive manufacturing is among the most common 3D printing technology used in the medical field, academic research, and industrial production of 3D parts. The medical application of VPP allows printing patients’ specific implants, organs, drug delivery systems, and other medical devices with complex geometry in a shorter time than traditional 3D manufacturing. Four main 3D printing techniques fall under VPP, namely continuous liquid interface production (CLIP), daylight polymer printing (DPP), stereolithography (SLA), and digital light processing (DLP). The last two are the focus of the present review paper. In recent years DLP and SLA 3D printing techniques have been primarily used in biomedical research and clinical medication for quick prototyping and production of medical devices such as surgical learning models of different human anatomical sites, surgical guides, drug delivery devices, and artificial tissues such as bones and teeth etc. The high accuracy, precision, the unique ability to produce highly complex porous structural geometries, the low printing cost, and the production time of 3D structures compared to subtractive 3D manufacturing make DLP and SLA suitable for medical applications, specifically in regenerative medicine. This review presents the recent trend of DLP and SLA as used in medical research related to bone tissue engineering highlighting the mechanical and biological properties of the resulting 3D bone structures. In addition, photopolymerization mechanisms, photocurable materials, and the working principles of DLP and SLA are introduced. Furthermore, the review informs readers on the availability of a wide range of materials used in tissue engineering that are compatible with either DLP or SLA and their thermal and mechanical properties. Lastly, the limitations and future applications of DLP and SLA are presented.This article is protected by copyright. All rights reserved.