The evaluation of the removal forces on the conus crowned telescopic prostheses with the finite element analysis (FEA)

The removable partial dentures supported by the telescopic crowns are an alternative for directly retained removable partial dentures. The stress distribution on the retainers and the surrounding tissues created by the telescopic and conus crowns of different sizes ( 4, 5, 6 mm) and taper (0degrees, 2degrees, 4degrees, 6degrees) was investigated with the finite element analysis (FEA) method. The stress values obtained were evaluated either as strain or tensional forces. The loosening force of the secondary crown being determined as 5 N, the increase in tension of the dentine, metal structure, alveolar bone, periodontal ligament and the pulp were determined by the increasing height and taper. The reason for the increase in tensional forces with increasing taper was the result of the constant loosening force of 5 N applied in all experimental models. The strain was more effective than the tension with the highest stress being in the cervical region of the metal structure. The aim of this study was to determine the force exerted on the teeth and surrounding tissues by the loosened secondary crown.