A finite element evaluation of mechanical function for 3 distal extension partial dental prosthesis designs with a 3-dimensional nonlinear method for modeling soft tissue

• Published in: The Journal of prosthetic dentistry 2014-10, Vol.112 (4), p.972-980
• Main Authors: Nakamura, Yoshinori, DDS, PhD, Kanbara, Ryo, DDS, PhD, Ochiai, Kent T., DDS, PhD, Tanaka, Yoshinobu, DDS, PhD
• Format: Article
• Language: English
• Subjects: Alveolar Process - physiology; Biomechanical Phenomena; Computer Simulation; Dental Abutments; Dental Clasps; Dentistry; Denture Design; Denture Retention - instrumentation; Denture, Partial, Removable; Elasticity; Finite Element Analysis; Gingiva - physiology; Humans; Imaging, Three-Dimensional - methods; Mandible - physiology; Models, Anatomic; Models, Biological; Nonlinear Dynamics; Periodontal Ligament - physiology; Stress, Mechanical; Viscosity
• ISSN: 0022-3913; 1097-6841
• DOI: 10.1016/j.prosdent.2014.03.011

Statement of problem The mechanical evaluation of the function of partial removable dental prostheses with 3-dimensional finite element modeling requires the accurate assessment and incorporation of soft tissue behavior. The differential behaviors of the residual ridge mucosa and periodontal ligament tissues have been shown to exhibit nonlinear displacement. The mathematic incorporation of known values simulating nonlinear soft tissue behavior has not been investigated previously via 3-dimensional finite element modeling evaluation to demonstrate the effect of prosthesis design on the supporting tissues. Purpose The purpose of this comparative study was to evaluate the functional differences of 3 different partial removable dental prosthesis designs with 3-dimensional finite element analysis modeling and a simulated patient model incorporating known viscoelastic, nonlinear soft tissue properties. Material and methods Three different designs of distal extension removable partial dental prostheses were analyzed. The stress distributions to the supporting abutments and soft tissue displacements of the designs tested were calculated and mechanically compared. Results Among the 3 dental designs evaluated, the RPI prosthesis demonstrated the lowest stress concentrations on the tissue supporting the tooth abutment and also provided wide mucosa-borne areas of support, thereby demonstrating a mechanical advantage and efficacy over the other designs evaluated. Conclusions The data and results obtained from this study confirmed that the functional behavior of partial dental prostheses with supporting abutments and soft tissues are consistent with the conventional theories of design and clinical experience. The validity and usefulness of this testing method for future applications and testing protocols are shown.