Stress Distribution with Different Implant Dimensions in Implant-Supported Partial Overdentures

Abstract

Objective: This study was conducted to evaluate the effect of changing implant dimensions on the stress distribution in the supporting structures in implant-supported partial over-dentures. Methods: The finished partial over-denture was checked in the patient's mouth. Construction of the physical model took place as the CT image acquisition was performed in a DICOM (Digital Imaging Communications in Medicine) format using Asteion 4 multi-slice CT scanner. After entering the data and initiating the segmentation procedure, a mask was constructed containing all the elements in the study. Then, construction of the Finite Element Model was carried out. A 100 Newton masticatory load was applied to the prosthesis in vertical and oblique directions. The percentage increase or decrease in the resultant stresses induced in the different model elements by utilizing different lengths and diameters of the dental implant was evaluated under unilateral vertical and oblique loading. Results: With the increase in the implant diameter, a statistically significant decrease (P≤0.05) in all forms of stresses was observed in the compact bone, cancellous bone and implant, as compared to the increase in the implant length. The decrease was in the Von Mises stresses, tensile, compressive and shear stresses under vertical or oblique loading. Conclusions: From the results of this study, it could be achieved that the increase in the implant diameter significantly reduced the stresses transmitted to the supporting bone compared to increasing the implant length and that the wider the implant diameter, the better the dissipation of the masticatory forces.