Influence of different customized abutment materials on stress distribution of different internal implant-abutment connections: finite element analysis

Star-shaped tube-in-tube and hybrid Morse taper with internal hex connections showed similar stress patterns, with values below the titanium alloy's yield strength and safe bone stress levels. Oblique loading, however, produced cortical strains above the safe limit. Zirconia, Co-Cr, and soft-milled Co-Cr-Mo abutments had moderate stress distribution, while titanium showed the most favorable profile. Both connections caused minimal screw deformation, suggesting low loosening risk.