Finite element analysis of non‐axial versus axial loading of oral implants in the mandible of the dog

Abstract

The influence of axial and non-axial occlusal loads on the bone remodelling phenomena around oral implants in an animal experiment is simulated in a finite element analysis. The axial and non-axial loading conditions were introduced by inserting a bilaterally supported fixed partial prosthesis and a cantilever fixed partial prosthesis on two IMZ implants in the mandible of beagle dogs. Earlier quantitative and qualitative histological analyses revealed a statistically significant different remodelling response between both loading conditions. Two-dimensional and three-dimensional models are built to analyse and compare von Mises equivalent stress, maximum principal stress, maximum principal strain and strain energy density distributions, first around a free-standing implant and subsequently around the implants of the two prosthesis designs under the respective resultant in vivo loads. Strong correlations between the calculated stress distributions in the surrounding bone tissue and the remodelling phenomena in the comparative animal model are observed. It is concluded that the highest bone remodelling events coincide with the regions of highest equivalent stress and that the major remodelling differences between axial and non-axial loading are largely determined by the horizontal stress component of the engendered stresses.

Application of the finite element method in dental implant research

“…'[Insert figure 6 about here]' Barbier et al 67 found that the horizontal loading of a freestanding implant evoked the largest maximum stresses, although the magnitude of the applied horizontal load was five times smaller than that of the vertical load. Non-axial loading has often been related to marginal bone loss, failure of osseointegration, failure of the implant and/or the prosthetic components and if connected to natural teeth, failure of the cement seal on the natural tooth.…”

Load-Application Devices: A Comparative Strain Gauge Analysis

“…In contrast, when non axial loads were applied on the specimen, the highest microstrain values were found by the SG 4 (Fig 2) placed closest to the tip of load application, indicating that the amount of load transmitted to the bone/implant interface depends on the site where the load was applied (6)(7)(8)12). Therefore, the first work hypothesis was accepted.…”

“…Conversely, when the occlusal force is applied on different locations and in a direction that creates leverage, it may cause stresses on the bone adjacent to the implant (4). In vitro (6) and in vivo (7) studies have revealed the negative effect of the application of non-axial loads when compared with axial loads.…”

“…Several techniques have been employed to evaluate the biomechanical loads on implants, such as photoelastic stress analysis (8)(9)(10), finite elements stress analysis (6,11), mathematical calculations (12) and strain gauge analysis (9,11,(13)(14)(15)(16)(17)(18).…”

Application of Finite Element Analysis in Implant Dentistry

“…Non-axial loads generate distinctive stress in the ridge especially in the cortical bone. The main remodeling differences between axial and non-axial loading are affected mostly by the horizontal component of the resultant stresses [53]. Therefore, for realistic simulation, combined oblique loads (axial and non-axial) are generally used.…”