PURPOSE: This study evaluated the biomechanical behavior of zygomatic implant configurations (intrasinus, extrasinus, extramaxillary) with four prosthetic framework materials (cobalt-chromium alloy, titanium, zirconia, BioHPP) in quad-zygoma full-arch rehabilitations under time-dependent quasi-static loading, including masseter muscle forces. MATERIALS AND METHODS: A quad-zygoma setup was used with anterior implants placed extrasinus and posterior implants placed intrasinus, extrasinus, or extramaxillary. Four framework materials were evaluated for each configuration. A time-dependent quasi-static occlusal load of 150 N was applied under vertical and 45° oblique directions, and a 300 N masseter muscle force was incorporated. Bone principal stresses, von Mises stresses in the implants, abutments, and frameworks, and prosthetic displacement were analyzed. RESULTS: Under both vertical and oblique loading, bone stresses were highest with BioHPP and lowest with cobalt-chromium (Co-Cr) frameworks, greatest in extramaxillary and lowest in intrasinus posterior implant placement. Implant stresses were highest in Co-Cr under vertical loading and in BioHPP under oblique loading. Abutment stresses were highest with BioHPP and lowest with Co-Cr, while framework stresses followed the opposite trend. Stress values peaked in the intrasinus and were lowest in the extramaxillary configuration for implant, abutment, and framework components. Prosthetic displacement was highest with BioHPP and lowest with Co-Cr, greater in extramaxillary than intrasinus placement. All stresses remained within mechanically acceptable limits. CONCLUSION: Zygomatic implant configuration and framework material significantly influence biomechanical behavior in quad-zygoma rehabilitations. Under the modeled conditions, the extrasinus configuration demonstrated a more balanced biomechanical response, whereas rigid frameworks reduced prosthetic deformation and limited stress transfer to the peri-implant bone.
Gerçek et al. (Mon,) studied this question.