Introduction:
The simulation studies1 focused mainly on the results of the structure and stress distribution. Therefore, it was necessary to carry out cyclic fatigue experimental tests to verify the results of MES analysis.

Aim of the study:
To evaluate the biomechanical properties of the implant-hybrid abutment and implant-all-ceramic abutment during functional load.

Material and method:
The study material included ten individual hybrid metal-ceramic abutments and ten individual ceramic abutments made of zirconium oxide (Robocam, Poland). Fatigue tests were carried out in two systems using a measuring stand. In the first one, the implant-screw-hybrid abutment system was examined, and in the second one, implant-screw-all-ceramic abutment system. The lifetime of the system elements was assessed, differentiated by the material from which the connector was made. Layouts were placed in the MTS Criterion dynamic testing machine (USA) at an angle of 30° to the axis of the implant. Fatigue properties were determined by testing five samples of each system for a constant value of the amplitude. Under dynamic load, systems with a hybrid abutment and with a ceramic connector were cycled 5 x 106 (ne) with a load amplitude of 20-200 N at a frequency of 15 Hz at a temperature of 20°C +/-5°C.

Results:
The results are presented in a graph of the number of load cycles for which each system maintained durability (on a logarithmic scale) and the corresponding load amplitude values (on a linear scale). The system with the hybrid connector remained durable during the assumed number of cycles, while the ceramic abutment failed the assumed number of cycles, with the loss of stability occurring after an average of 4.6 million cycles.

Conclusions:
Based on the obtained results, it can be concluded that the hybrid abutment can be safely used in the oral cavity, unlike the allceramic abutment, which failed to withstand the tested loads.