Contribuition to the planning of implant-supported RPD in the dista region

ABSTRACT

This study compared the suitability of different connections between abutment tooth and prosthesis and between prosthesis and implant in a model of a mandibular distal implant-supported RPD. Finite Element Analysis (FEA) was used, with the application of strictly vertical loads, varying the type of connection, rigid or hinged, between the RPD and the abutment tooth, and between the RPD and the implant. In the model, the load on the abutment tooth rose from 15.2 N to 33.2 N when the link between the abutment tooth and the RPD changed from hinged to right and the link between implant and RPD changed from rigid to hinged. The load on the implant decrease from 84.8 N to 66.7 N when the link between the abutment tooth and the RPD changed from hinged to rigid and the link between the implant and the RPD changed from rigid to hinged. The bending moment on the implant decrease from 0.18 Nm to zero when the connection between the implant and the RPD changed from rigid to hinged. Maximum deflection of the RPD varied from -1.95 micrometer to -5.09 micrometer as the links changed from right to hinged. A rigid connection between the abutment tooth and the RPD transmitted higher loads to the abutment tooth and decreased loading on the alveolar ridge mucosa and on the implant when compared to a hinged connection, and a hinged connection between the implant and the RPD decreased the bending moment transmitted to the implant and increased loads on the alveolar ridge mucosa and on the abutment tooth. We concluded that a hinged connection is recommended between the prosthesis and the implant to preserve the implant and prevent bone resorption.