Influence of clinic design of the prostheses with ERA attachment for distal extension defect: A three-dimensional finite dement analysis / 实用口腔医学杂志

ABSTRACT

Objective:To evaluate the stress distribution and displacement pattern in the restoration of Stern-ERA attachment mandible removable partial denture (RPD) with different designs through three-dimensional (3D) finite element (FE) analysis.Methods:3D-FE models were established based on human CT data and manufacturer's catalog.Vertical and 45° lingual oblique forces of 100 N were applied on the artificial teeth of the RPD.Three ERA attachment partial dentures with different bracing arms were designed,namely the basic design,rest bracing arm design and cross-arch bracing arm design.The von Mises stresses and displacements of abutment teeth and mucosa under denture base were analysed.The displacement of denture bases was examined.Results:Under the vertical and oblique loading,the maximum yon Mises stress was found at the distal shoulder on the distal abutment.The maximun displacement was observed at the buccal and distal occlusal surfaces of the distal abutment.The maximum displacement on the abutment was found to be the highest in rest bracing arm design group (14.91 μm and 63.09 μm),followed by the basic design group (9.38 μm and 50.56 μm) and the cross-arch bracing arm design group exhibited the smallest displacement (8.85 μm and 47.31 μm).Conclusion:The basic design Stern_ERA attachment for unilateral mandible distal extension defect appears to be more reasonable compared with rest arm and crossing-arch arm design from biomechanical point of view.