engleski

Mechanical properties of reinforced composite resin

In order to improve mechanical properties of composite resin, the influance of polyethylene fibers on flexural strenght and modulus of elasticity was evaluated. The research encompassed two groups of commercial composites: microfilled (Charisma, Heliomolar, Dentacolor) and hybred (Pekafill, Tetric). The flexural strenght and modulus of elasticity were measured in three groups of samples for each tested material: control, samples reinforced by longitudinally oriented fibres with and without bonding agent. The 8 composite specimens for each group were prepared in metal mould (2 x 2 x 25 mm). The mould was manually filled in three layers, incrementally. Each layer was adittionally filled with bundles of fibres of the same lenght as the specimens. Filled mould was covered with metal plate and placed ih hydroulic press where the pressure was 100 kPa. After squeezing out the excess, each specimens side was light cured for 3 minutes, polished, therocycled for 500 cycles of 1-minute water baths at 5° C and 55° C. The tested mechanical properties of composite resins were determined on Zwick Materialprufung machine. The data obtained were subsequently processed with computer program. The results indicated statistically significant improvement (p<0.05) in flexural strenght and modulus of elasticity between control and reinforced composite specimens of each tested material. There was no significant between specimens with pretreated and with no treated polyethylene fibers.

mechanical properties ; composite resin

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