3D Numerical Calculation of Stress at the Gum-Denture Interface

Objectives: The aim of this study was the accurate 3D modeling of the denture and mandible assembly from computer tomography data sets and numerical simulation to evaluate the stress characteristics of the denture, jawbone, underlying oral mucosa, and abutment teeth.
Methods: A model was generated of a geometrical, representative partial denture incorporated onto the dental arch of the mandible and supported by three abutment teeth. To create this geometrical model, three independent CT datasets (jawbone, abutment teeth, and removable partial cast denture) were combined by Boolean operator. Additionally, CATIA V5 was used to adapt the reciprocal and retentive arms as well as occlusal rest to the abutment teeth.
Further attention was focused on the retention of the denture onto the jawbone assembly under application of occlusal forces, as static and transient scenarios. The static case was further subdivided based on the load application methodology into maximum voluntary bite forces, eccentric loading, and oblique loading scenarios.
Results: Stress parameters exhibited on the contact spaces in general and particularly between the denture and oral mucosa were evaluated, providing valuable information about the retention of the denture onto the jawbone across various loading configurations. The occlusal forces were transmitted onto the denture, through to the denture base, then to the oral mucosa, and finally to the jawbone. Maximum stresses in the jawbone were exhibited around the roots of the abutment teeth. Furthermore, the outcomes of this study illustrated that the denture remained in a ‘stick condition’ upon the application of occlusal forces, which tend to retain the denture in the perfect position.
Conclusions: In summary, the established numerical model can be used as a reference for future simulations of different load scenarios or to determine the influence of denture adhesive creams or other adhesive sheets.