الفهرس | Only 14 pages are availabe for public view |
Abstract The cautious control of biomechanical loading on dental implants is imperative to enable the long-term success of rehabilitation. As implant surface modifications, alterations in the implant abutment connection system have been one of the design parameters most changed by implant manufacturers. Rationales for changing the implant abutment connection design include an attempt to establish better prosthetic stability and decrease of the implant abutment gap that have been reported to occur in many implant systems Also, implant-supported cantilever fixed prostheses remain a challenge to a dentist. Due to the difficulty of the experiment about implants supported cantilever prostheses in patient‟s mouth, in vitro studies or finite element studies have been done since last decade However, these studies were mostly for distal cantilever, and consistent studies concerning mesial cantilever were definitely lacking. As a result, the comparative study between mesial cantilever prostheses and distal cantilever prostheses with different types of connection there for this study aims to evaluate the effect of the different FPD designs (fixed-fixed, mesial and distal cantilever prosthesis) and the geometrical designs of the implant connection systems on the stress distribution. A total of forty two Fixed dental prosthesis were fabricated in this study. Three epoxy resin models with an edentulous span of missing mandibular second premolar, first and second molars will be constructed. Two implants were be selected and inserted in each epoxy model to simulate different designs for replacing the missed teeth: group I: two implants were be inserted replacing lower second premolar and second molar with fixed-Fixed dental prosthesis. group II: two implants were be inserted replacing lower first molar and second molar with mesial cantilever Fixed dental prosthesis. group III: two implants were be inserted in lower second premolar and first molar with distal cantilever Fixed dental prosthesis. The samples will be divided in to two main groups according to the implants’ connection design. In each group two types of abutment connections will be used: Subgroup A: Two implants with hexagonal connection. Subgroup B: Two implants with Tri-Lobe connection. The Fixed dental prosthesis were constructed using CAD/CAM system. Stress distribution were tested using strain gauge. The Data will be collected, tabulated and statistically analyzed Results: The fixed-fixed design showed the best stress distribution. The trilobe connection type shower higher strain in bone than hexagonal type. Conclusion: |