Influence of abutment periodontal quantity on stress distribution in supporting tissue on extracoronal attachment denture with unilateral distal-extension prosthesis

Objective To investigate the stress distribution in the unilateral distal-extension attachment denture supporting tissue with different abutment periodontal quantities.Methods We reconstructed the three-dimensional finite element models of the extracoronal attachment denture with mandibular KennedyⅡ dentition defect,analyzed the stress distribution of the denture supporting tissue with von Mises ability of sustain pressure when vertical forces were applied,and compared the absorbed-periodontal abutment models with the normal-periodontal abutment models.Results Compared with the normal-periodontal abutment models,on the absorbed-periodontal abutment models,the maximal pressure increased by about 30% on the abutments,about 10% on the periodontal tissues,about 36% and 14% on the alveolar bone under the denture; when the abutment number was increased from two to three,the pressure of supporting tissues did not obviously decrease.Conclusion When the distant-abutment periodontal tissues were absorbed by 1/3,the pressure on the abutments periodontal tissues and the alveolar bone under the denture was obviously enlarged,and increasing the abutment number couldn't effectively decrease the pressure of supporting tissues.