Stress Analysis of Ball and Locator Attachments and Bone in Overdenture Supported by Tissue Level and Bone Level Implants: A Three-dimensional Finite Element Analysis

Abstract

Background: This study evaluates the stress distribution and force distribution on the surrounding bones in ball and locator attachments in bone level and tissue level implants. Materials and Methods: Primarily scan of training GOS model, fabricated denture, ball, and locator attachments was prepared. After assembling dens point clouds in CATIA V5R21 software, two bone level implants and two tissue level implants were inserted into the computer modeling of the mandible and for both, ball and locator attachments were applied. 100 N/cm occlusal load was applied on incisor, canine, and first molar areas. Modes were analyzed in ABAQUS 6.13 and the map of force distribution and numerical values were obtained. Results: The highest obtained von Mises numerical value belongs to ball attachments of bone level implants in molar areas (11.14 Mpa). The highest amount of stress for ball attachments was from hex to first thread area. Numerical values of transferred stress to the hex and first thread of screw in ball attachments were higher than locator attachments. The highest numerical value of von Mises was belongs to locator attachments of tissue level implants. Conclusions: Given the limitation of this study, it is cleared that the probability of overloading and screw fracture in ball attachments is more than locator attachments and also in bone level implants is more than tissue level implants. While the transferred force to the bone in locator attachments is higher than ball attachments and also it is higher in tissue level compared to bone level implants.