This study evaluated the stress distribution in different cement-retained implant-supported prostheses with a hybrid abutment.
MATERIALS AND METHODS
Two factors were evaluated: restorative material for the crown and hybrid abutment - zirconia, lithium disilicate and hybrid ceramic, yielding 9 combinations. For finite element analysis, a monolithic crown cemented on a hybrid abutment was modeled and cemented on a titanium base (Ti base). An oblique load (45°, 300 N) was applied to the fossa bottom and system fixation occurred on the bone's base.
Each structure was evaluated separately to find the possible weaknesses in geometry and failure criteria. In this context, results demonstrated a significant decrease of maximum principal and von-Mises stresses concentration when crowns with high elastic modulus are cemented onto a hybrid abutment with lower elastic modulus.
Considering this theoretical study for a Morse taper implant, the association of a rigid crown with a more resilient hybrid abutment reduces the tensile stress concentration in the restoration cervical region.