Finite Element Analysis of the Influence of Implant Tilting and the Direction of Loading on the Displacement and Micromotion of Immediately Loaded Implants.

Objectives: To investigate the outcome of the loading direction and implant tilting on the micromotion and displacement of immediately placed implants with finite element analysis (FEA). Materials and Method: Eight blocks of synthetic bone were created. Eight screw-type implants were inserted, four axially and four slanted, each measuring 11 mm in length and 4.5 mm in diameter. The axial implants and the tilted implants were distally inclined by 30°. The top of the abutment was subjected to 180 N vertical and mesiodistal oblique (45° angle) loads, and the displacement of the abutment was measured. The abutment displacement and micromotion were estimated, and nonlinear finite element models simulating the in vitro experiment were built. In vitro studies and FEA data on abutment displacement were compared, and the reliability of the finite element model was assessed. Result: Under oblique stress, abutment displacement was larger than under axial loading, and it was also greater for tilted implants than for axial implants. The consistency of the in vitro and FEA data was satisfactory. Under vertical stress, the highest micromotion values in the axial and tilted implants were extremely near. Conclusion: Under mesiodistal oblique stress, tilted implants may have a smaller maximum amount of micromotion than axial implants. The loading direction had a significant impact on the highest micromotion values. The abutment displacement values were not reflected in the maximum micromotion measurements.

Compressive Strength Evaluation of Three Distinct Implant Design Approaches.

Objectives: The study was done to assess the implant-abutment interface static compressive. strength of three design types and implant-abutment connection failure style. Materials and Methods: The implants at 306 with respect to the y-axis were aligned using a stainless steel holding device. Twenty specimens from each system totaled 60 total. A unidirectional vertical piston in a computer-controlled universal testing machine (MTS 810) generated static compression loading until failure. Specimens were macroscopically examined for fracture of the screw and implant, abutment looseness, and longitudinal displacement. Analysis of variance was used to analyze the data (ANOVA). Result: The screw-vent system had a mean compressive strength of 335.6 22.7 psi for the Unipost system, 384.3 37.1 psi for the screw-vent system, and 245.3 25.4 psi for the ITI-1 piece abutment connection. Conclusion: The connection between the Unipost implant and abutment showed a statistically significant variation.