Non-rigid connectors in fixed prosthodontics: Current concepts with a case report

Abstract

The occlusal forces applied to a fixed partial denture (FPD) are transmitted to the supporting structures through the pontic, connectors, and retainers. Variables that may influence the longevity of an FPD and its abutment include occlusion, span length, bone loss, and quality of periodontium. The excessive flexing of the long-span FPD, which varies with the cube of the length of span, can lead to material failure of prosthesis or to an unfavorable response. Biomechanical factors such as overload, leverage, torque and flexing, induce abnormal stress concentration in an FPD. Stress concentration is found in the connectors of the prosthesis and in the cervical dentin area near the edentulous ridge. This factor plays an important role in the potential for failure in long-span FPD. The conventional use of a nonrigid connector (NRC) aids in compensating for the difference in the resistance and retention form between the abutments. The design and passive fit of NRC is critical to the success of a long-span FPD. This paper presents the current concepts in the design of an NRC and a case report of Pier abutment treated with FPD having Tenon-Mortise Connector.