Effect of diameter, length and crown-to-implant ratio on the stress distribution around dental implants: Finite element analysis

Dental implants are widely used to replace missing teeth. The crown-to-implant ratio is a determinant factor for the survival/success of dental implants. The aim of this study was to investigate the effect of diameter, length, and crown-to-implant ratio on the stress distribution around dental implants using the finite element analysis (FEA) method.

In this in vitro study, the cone-beam computed tomography (CBCT) of a patient with an edentulous mandible was used to create a three-dimensional model. The model was uploaded into the Mimics software and the contour model of the mandible was produced. The final file was uploaded into the ABAQUS software for FEA. The mandibular first molar was simulated and reconstructed using six models and in accordance with implant dimensions (diameter: 4.1 and 4.8mm; Length: 6,8,10mm) and axial forces of 200 N and angles of 0°, 15°, 30°, and 45°. The von Mises stress was used to determine the yielding of materials under multifaceted loading from the results of uniaxial tensile tests.

The maximum value of von Mises stress, in all six models was observed in the implant, crown, and cortical and cancellous bones, respectively (491.7, 303.5, 205.8,52 MPa). The highest stress value in all models was observed in the implant neck and the stress levels were decreased towards the apical implant. The stress value around the implant increased with increasing crown-to-implant ratio (69.2, 77.6, 92.9 model <1, 1>1 respectively).

The stress value around the implant increased with increasing crown-to-implant ratio and inclination angle and decreasing diameter and length.