Examination of stresses created by zygomatic and dental implants applied in combined form and implants placed with the “All-on-Four” technique in bilateral atrophic maxilla by finite element analysis

Aims: In severely atrophic posterior maxillae, there is usually not enough bone to place conventional dental implants. Dental implants and zygomatic implants placed with the “All-on-Four” technique have frequently been preferred in recent years because they eliminate the need for grafting, shorten the treatment time, and reduce the morbidity rate. The aim of our study was to select the most accurate surgical planning according to the stress values resulting from the forces applied to the combined zygomatic and dental implants and dental implants placed with the “All-on-Four” technique in the models we created. Methods: In the present study, 2 group models were established. In group 1 model, one dental implant was placed in the canine and second premolar tooth regions with the “All-on-Four” technique. In the group 2 model, one dental implant was placed in the canine tooth region and one zygomatic implant was placed in the 1st molar region. In the prosthetic superstructure, a force of 150 N was applied vertically from the region of teeth 4-5-6 and 100 N was applied obliquely at an angle of 30o. Results: In the present study, when the von Mises stress values on the implants were analyzed, it was found that the highest stress occurred in group 2 under vertical forces and in group 1 under oblique forces. Conclusion: Based on these results, it is concluded that the most ideal planning in the rehabilitation of bilateral atrophic maxilla is group 1 with dental implants placed with the “All-on-Four” technique under vertical forces and group 2 with zygoma and dental implants under oblique forces.