Three-dimensional printing (3DP) is presently seen as a game-changing manufacturing process in many domains, including medicine. The underlying processes have been designed to be compatible with polymers, ceramics and metals, but the integration of more complex functions into 3D printed materials remains lacking. Here, we expand on the repertoire of 3D printable materials to include antimicrobial polymer resins, which are essential for the continued development of 3D printed medical devices due to the status of biomaterial-associated infections as the most common mode of implant failure. We demonstrate that dental 3D printed objects fabricated by the stereolithography process kill bacteria on contact when positively charged quaternary ammonium groups are incorporated into the photo-cured resins. Biocompatibility issues were curtailed by limiting the leaching of positively charged polymers out of the composites while the mechanical properties of the pristine polymer matrix were maintained, possibly qualifying these materials for future clinical use.
