Effect of Implant-Abutment Connection Type on Stress Distribution in Peri-Implant Bone and Abutment Micromovement: A Three-Dimensional Finite Element Analysis.

This study assessed the effect of implant-abutment connection type on stress distribution in peri-implant bone and abutment micromovement using finite-element analysis (FEA). Dimensions of three implant-abutment designs were measured by a three-dimensional scanner and transferred to SOLIDWORKS. An elemental model was designed using ABAQUS. Each implant was placed in bone at the crestal level. A 100-N load was applied at a 45° angle relative to the longitudinal axis of the implant in the buccolingual direction from the palatal toward the buccal and coronal parts of the abutment. Shear stress, von Mises stress, and micromovement of the abutment relative to the fixture were analyzed. Data were reported qualitatively and quantitatively using ABAQUS. The von Mises stress in all three samples decreased from the crest toward the apical area and was distributed homogenously. Maximum stress concentration was at the most coronal part of the implant body in the midbuccal area. In cancellous and cortical bone, stress decreased from the crest toward the palate and was at its maximum at the midbuccal point in the bone crest. Stress in cortical bone was more homogenous and in cancellous bone was higher. Shear stress was higher in the buccal than in the palatal area, and at its maximum shear stress and equal in the mesiobuccal and distobuccal areas. Micromovement was 4.25 μm in an Astra implant, 5.42 μm in a Intra-Lock implant, and 6.63 μm in an SPI implant. The distribution of von Mises and shear stress was the same in bone around the three implant connection types; however, abutment micomovement differed.