Photopolymerizable resin-based 3D printed biomedical composites: Factors affecting resin viscosity

3D printing of biomedical composites involving the use of particulate fillers and biocompatible polymers have shown promising potential in terms of tunability of physico-chemical and mechano-biological properties. To this end, photopolymerizable resin-based additive manufacturing technologies such as stereolithography (SLA) and digital light processing (DLP) can prove to be game-changers based on precision, versatility and controlled manipulations. These technologies provide versatility and controlled manipulations of the photopolymerization kinetics by altering spatial and temporal parameters. One critical factor in ensuring the success of such technology in biomedical composite development is to regulate the viscosity of the photopolymerizable resin that is used as a 3D printable matrix. This brief review highlights the crucial factors influencing the resin viscosity and printability of photopolymerizable resin. Different fabrication approaches for developing biomedical composites through the use of the SLA/DLP technique have been reviewed. The article also underscores the importance of viscosity optimization and printability from the perspective of fillers, photopolymerizable resins and additives towards efficient 3D printing of new generation customized biomedical composites.