In vitro comparative study of the mechanical behavior of a composite matrix reinforced by two types of fibers (polyethylene and glass)

Fiber-reinforced composites have been used to replace the metal framework in fixed partial dentures. This study evaluates and compares the influence of two fiber reinforcements: polyethylene (Connect) and glass (GlasSpan) on the mechanical properties of a commercial (Artglass) particulate composite. Flexure, compression and fracture toughness tests were conducted. The flexure tests were made by three-point bending, using six samples of each material with a fiber layer next to base. The compression tests were made in a universal mechanical testing machine with four samples of each material with a fiber layer next to base. Fracture toughness testing was made by three-point bending, using six samples of each material with a fiber layer 4 mm upward away from the base and a single notch cut transversal to fibers, without touching them. After statistical analysis, it was concluded that the flexure strength is equal for bars reinforced by polyethylene or glass fibers. The compressive strength is higher in the composite reinforced by glass fibers. The flexure elastic modulus and deflection are equals in both materials whereas the fracture toughness is greater in the composite reinforced by polyethylene fibers.