Three Dimensional Finite Element Stress Analyses And Comparison For Attachments Used In Extensional Removable Partial Dentures

Attachments are used in western countries for a long time.There are about three kinds of attachment are used in extensional removable partial dentures. The first is rigid attachment, the second is resilient attachment and the third is hinge attachment. Many researches about those result in vary effects.Further investigation is made here for attachment by three dimensional finite element stress analyses method. Four models is established by coordinate test, element divided and compute input, base on one case that is 178 lost removable partial denture. 1. Bolt rigid attachment. 2. hinge attachment which allow the denture active in a plant. 3. Resilient attachment which allow the denture active in vertical. 4. 20 ° occlusal rest conventional denture. The aim is test and compare effects of abutments mucous of various prosthet and give a conduction to clinic .The designs of abutments, periodontal membrane, cortical and cancellous bone, mucous membrane are same in various experiment. So results can be compared. Five cases of load are in tests. 1. Vertical load. 2. Buccal 30 ° load. 3. Distal 30 ° load.4. Lingual 30 ° load. 5 .Mesial 30 ° load. The Value of load is 98N.Result:1. When use rigid attachment, load is bared mainly by abutment, the stress in...