Studies on Slurry Extrusion for Dental Restoration

This study investigates dental restoration via dental powder delivery by slurry extrusion, followed by laser densification of these extruded slurries. The entire process is fully controlled by a computer. The shape of the extrudate before laser densification depends strongly on the formulation of slurries. Slurries prepared in a stable pH range can disperse high volume of solids, but have low viscosities and spread uncontrollably when extruded. In contrast, slurries first prepared in a stable pH range and subsequently adjusted to an unstable pH range have exhibited pseudoplastic behavior. Such slurries have a low extrusion pressure to avoid phase separation, and at the same time their yield points are high enough to maintain the shape of extrudates.