Dental composites reinforced with glass fibers have a low tensile modulus and relatively low fatigue resistance. The aim of the study was to analyze the fatigue properties of a dental composite reinforced with polyaramide fibers under the influence of a cyclic, vertical load. For this purpose, we designed a thermoformable template, corresponding to the construction of adhesive bridges in the side section of the jaw. Fifty-four composite samples were made for the study. They were divided into three groups—control (K) and two experimental groups (R1 and R2). The experimental samples were subjected to cyclic fatigue using 75 N load. The number of cycles was 4690 and 20,100. The study used a three-point bending test. Statistical analysis showed a change in elasticity in groups related to the number of load cycles. The study showed that the samples from the control group required the greatest force to break in relation to those subjected to the work cycles. The maximum force in control (K) group was 738.1 N, R1—487.8 N, and R2—451.4 N. The determined algorithm showed a change in deflection associated with the increase of force value. The study did not show any relationship between the type of sample fracture and the number of load cycles