Finite Element Analysis of OT Bridge fixed prosthesis system

The treatment modality for completely edentulous arches has shifted from complete dentures to dental implants during the last 15-20 years. Tilting of implants has reduced the concern of resorbed posterior ridges in completely edentulous patients with “All-on-four” and “All-on-six” concept of dental implants. The purpose of this study is to compare the biomechanical behaviour of the “All-on-four”, “All-on-six” models with tilted distal implants at different angulations of 30 and 45 ° with four parallel placed implant-supported fixed prosthesis, and six parallel placed implant-supported fixed prosthesis models as controls using three-dimensional finite element analysis. The results showed that in all the models, in cancellous bone, cortical bone, implant and prosthesis – “All-on-four” model with distal implants tilted at an angulation of 30° showed stress values less than or equivalent to all the other models except on the implant in the presence of cantilever and on prosthesis during full mouth biting load where maximum stresses were observed. The study shows that All-on-four concept with tilted distal implants at an angulation of 30° showed stress values favourable for the rehabilitation of completely edentulous maxilla, but the presence of cantilever remains an area of concern.

Download Full-text

An evaluation of the stress effect of different occlusion concepts on hybrid abutment and implant supported monolithic zirconia fixed prosthesis: A finite element analysis

The Journal of Advanced Prosthodontics ◽

10.4047/jap.2021.13.4.216 ◽

2021 ◽

Vol 13 (4) ◽

pp. 216

Author(s):

Nilgün Gulbahce Yesilyurt ◽

Ali Riza Tuncdemir

Keyword(s):

Finite Element Analysis ◽

Finite Element ◽

Stress Effect ◽

Element Analysis ◽

Monolithic Zirconia ◽

Fixed Prosthesis

Download Full-text

Three-Dimensional Finite Element Analysis of Osseointegrated Implants Placed in Bone of Different Densities With Cemented Fixed Prosthetic Restoration

Journal of Oral Implantology ◽

10.1563/aaid-joi-d-19-00144 ◽

2020 ◽

Vol 46 (5) ◽

pp. 480-490

Author(s):

Kasthuri Chidambaravalli ◽

Vinod Krishnan

Keyword(s):

Finite Element Analysis ◽

Finite Element ◽

Element Analysis ◽

Osseointegrated Implants ◽

Bone Segment ◽

Implant Abutment ◽

Stress Deformation ◽

Dimensional Finite Element ◽

Fixed Prosthesis ◽

Von Mises

A key factor for a successful dental implant is the manner in which stresses are transferred to the surrounding bone. Strength of bone is directly related to its density. Maximum stresses are reported to be incurred by the crestal cortical bone surrounding the implant. Displacement of implants is significantly higher in soft cancellous bone than dense bone. Implants are often placed in bone of different densities to support fixed dental prostheses. This study was aimed at assessing stress and deformation generated by osseointegrated implants placed in bone of different densities on a cemented fixed prosthesis when subjected to static and dynamic loading. A 3-dimensional finite element analysis was done on a computer-aided design model simulating maxillary bone segment with 2 different bone densities (D2 and D4). The effect of loading was evaluated at the implant–bone interface, implant–abutment interface, abutment, implant abutment connecting screw, cementing medium, and fixed prosthesis. Stresses were calculated using von Mises criteria calibrated in megapascals and deformation in millimeters. These were represented in color-coded maps from blue to red (showing minimum to maximum stress/deformation), depicted as contour lines with different colors connecting stress/deformation points. The study found greater von Mises stress in D2 than D4 bone, and in D2 bone the component with higher stress was the implant. Deformation was greater in D4 than D2 bone, and in D4 bone the abutment-prosthesis interface showed more deformation.

Download Full-text