A three-dimensional finite element stress analysis of angled abutments for an implant placed in the anterior maxilla.

PURPOSE

A three-dimensional mathematical model of the maxilla was developed that was used to analyze the stresses and strains produced by an abutment system capable of three abutment angulations.

MATERIALS AND METHODS

Computed tomography was used to derive the geometry and density values used for the maxillary model. A 3.8 x 10-mm cylindrical implant was embedded in the right central incisor position at a 35 degrees angle to the horizontal plane and parallel to the angulation of the bone site. All geometric and elastic properties for the fixture and the surrounding bone were included in the model. A simulated occlusal load of 178 N was applied along the long axis of 0 degrees, 15 degrees, and 20 degrees abutments. The mathematical models were solved by the Cray Y/MP Ohio Supercomputer (Cray, Eagan, MN) using the ABAQUS software program (Hibbitt, Karlsson, and Sorenson, Providence, RI).

RESULTS

Numerical and graphic results were generated for the maximum (tensile) and minimum (compressive) stresses and strains. Principal stresses occurred predominantly in the cortical bone layers, whereas strains occurred mostly in the cancellous bone.

CONCLUSIONS

In general, there was an increase in the magnitude of stress and strain as the abutment angulation increased. Reported stresses and strains for all three angles were within or slightly above the physiological zone derived from animal studies. A need to investigate the response of human bone to stress and strain was indicated.