Biological-data-based finite-element stress analysis of mandibular bone with implant-supported overdenture.

Background: This study aimed to evaluate the stress distribution in a mandibular bone with an implant-supported overdenture by a biological-data-based finite element analysis (FEA) utilizing personal CT images and in vivo loading data, and to evaluate the influence of the number and alignment of implants and bone conditions on the stress in peri-implant bone.

Methods: FEA models of a mandible were constructed for two types of overdentures: 4 implants supported overdenture (4-OD) and 2 implants supported overdenture (2-OD). The geometry of these models was constructed from CT images of a subject, who wore an implant-supported overdenture.

Stress distribution in the peri-implant bone with splinted and non-splinted implants by in vivo loading data-based finite element analysis.

The aim of this study was to evaluate stress distribution in peri-implant bone and to investigate the influence of splinting implants by finite element analysis (FEA) with in vivo loading data. The magnitude and direction of the force exerted on implants during maximal voluntary clenching of a subject were recorded with 3-D piezoelectric force transducers. FEA using in vivo loading data was conducted on splinted and non-splinted models with two implants.

Bifurcations to diversify geometrical patterns of shear bands on granular material.

The mechanism to diversify geometrical patterns on granular material was elucidated using a group-theoretic image analysis of patterned shear bands, with associated numerical bifurcation analysis. Pattern formation of granular materials took the course of the evolution of a diamondlike diffuse bifurcation breaking uniformity, followed by further bifurcation, mode jumping, and the formation and disappearance of shear bands through localization. A chaotic explosive increase of possible postbifurcation states was emphasized as a mechanism to diversify geometrical patterns.