Strength tests of fiber-reinforced composite with ultra-high molecular weight polyethylene

Introduction. Ultra-high molecular weight polyethylene (UHMWPE) fibers are inert, thus their adhesion to the organic polymer matrix of the composite material may not be rewarding. Therefore, these types of fibers have not yet come into widespread use in dentistry. Aim of the study. To evaluate selected strength characteristics of the UHMWPE fiber-reinforced composite whose surface was chemically activated and then impregnated with a mixture of dimethacrylate resins and coated with a microhybrid composite material. Material and method. Tests were carried out which allowed to evaluate selected mechanical properties of the material under static stretching and shearing. Results. Based on the experiments the following values were calculated: Young’s elastic modulus Et = 3583.97 ± 1325.75 MPa, tensile stress σ = 59.73 ± 7.54 MPa, maximum tensile force Fmax = 121.23 ± 17.92 N, linear extension εt = 0.03 ± 0.003 and tangential stress τt = 4.99 ± 1.19 MPa. The loss of adhesion of the material to the hard tissues of the tooth was typical of the mixed adhesive-cohesive breakthrough. Conclusions. The study revealed high and desired mechanical strength in both the tensile test and in the shear test, which may justify the effective use of this type of fibers in clinical practice. The phenomena of saturation and penetration of the resin into the space between the fiber bundles occurring in the oxidation process did not negatively affect the mechanical properties of the material tested.