Development of three directional three-dimensional composite dentures with short glass fiber reinforced methyl methacrylate using fused filament fabrication process

Fiber reinforced additive manufacturing (FRAM) is becoming a subject of great interest in dentistry as it offers opportunities that could be explored in the dental field concerned with the “design and manufacture” of devices. Herein, we evaluated the practicality of FRAM for constructing patient specific and affordable composite denture bases with improved mechanical and clinical properties: polymethylmethacrylate (PMMA) as matrix was reinforced with short glass fibers (SGFs) using the fused filament fabrication (FFF) process. Representative parts for this study, were built with different layer heights (0.2, 0.1, 0.05 mm) and volume fractions (0%, 2.5%, 5%) in three mutually perpendicular directions (0˚ in X-Y plane, 90˚ in X-Y plane, and 90˚ in Z axis), and analyzed for surface roughness (resolution) and mechanical properties (tensile, flexural, compressive properties). Mechanical properties were influenced significantly by printing direction, layer height, and volume fractions; in general, parts with lower layer heights and higher SGFs reinforcement constructed in 0˚ in X-Y plane showed improved mechanical properties and good surface finish. Additional scanning electron microscopy was performed to study the effect of fiber distribution, fiber breakage, fiber accumulation and the adhesion at the interface of the PMMA/SGFs composite materials. The practical implications of the study at a “proof of concept stage” are low-cost manufacturing of highly accurate, lightweight and affordable medical devices with enhanced patient comfort in the long term and improved clinical properties particularly for geriatric use. Keywords: Fiber reinforced additive manufacturing, Fused filament fabrication, Denture base, Composite, layer height, surface roughness