Effect of Mixing Silanized Poly Propylene and Siwak Fibers on Some Physical and Mechanical Properties of Heat Cure Resin Denture Base

PMMA is used in construction of denture base due to several advantages, including biocompatibility and optimal appearance. Operators and patients complain from fracture of acrylic denture base material attributed to decreased resistance to impact, flexural or fatigue stresses. The aim of the research is to assess the effect of addition of silanized mixture of siwak and poly propylene fibers on PMMA denture base. Fourteen acrylic resin specimens were prepared for each test (Impact strength, Transverse strength, Shear bond strength, Thermal conductivity, Shore D hardness, Surface roughness and Water sorption) the specimens were grouped as control group (n=7) :no fibers additive and experimental group (n=7):(2 %) silanized mixture of siwak and poly propylene fibers, 4 mm length, FT-IR was done to investigate the presence of functional groups of coupling agent (TMSPM) on the tested fibers, independent t-test was used for statistical analysis of the resulted data. Statistical analysis indicated that silanized mixture of poly propylene and natural fibers (siwak) produced significant increase (p≤0.05) of impact strength and highly significant increase (p≤0.01) of shear bond strength, transverse strength, thermal conductivity and shore D hardness of heat cure acrylic resin while a non significant increase (p>0.05) of surface roughness and water sorption properties was observed in comparison to non fiber reinforced resin specimens. The addition of silanized mixture of siwak and polypropylene fibers into heat cure PMMA improve the tested physical and mechanical properties.