Stress distribution in the supporting tissue with oblique forces on extracoronal attachment denture to mandibular Kennedy I dentition defect

Objective To investigate the stress distribution in the bilateral distal-extension attachment denture supporting tissue with oblique forces. Methods Reconstruct the three-dimensional finite element models of the extracoronal attachment denture with various abutment number to mandibular Kennedy Ⅰ dentition defect,analyze the stress distribution of the denture supporting tissue with Von Mises ability of sustain pressure when oblique forces were applied. Results With oblique forces,the max Von Mises stress of the distant-abutments periodontal membrane were found at the buccolingual cervix dentis; while the abutment number was increased,the max pressure of the distant-abutments periodontal membrane and the alveolar bone decreased;while the abutment number was increased from one to two,the pressure obviously decreased,and the number from two to three,the pressure decreased slowlier. Conclusion With oblique forces,the pressure decrease of supporting tissue of extra-coronal attachment is not in proportion to the increase of abutment number.