Three-dimensional finite element analysis on preferable cast circumferential clasps arms design

Objectives: High stresses which result during functions in the cast clasps arms are the main causes of deformations or fractures. The purpose of the study was to evaluate the stress distribution in three-dimensional finite element analysis models of clasps and to select their preferable design. Materials and Methods: A three-dimensional finite element analysis was used for the investigations. Preformed clasp wax patterns for circumferential clasps were selected and three parameters namely length, thickness and width at the base and tip were measured to generate purposely designed experimental three-dimensional models. Generated stresses and deformations were calculated numerically and plotted graphically. The study was made at the Specilaization of Dental Technology of the University School of Dentistry Timisoara, Romania, in collaboration with the Politehnica s University Department of Strength of Materials from the same town during the period 2004-2005. Results were displayed as colored stresses and displacements contour plots to identify regions of different values. The corelations between maximal stress and deformation allow the selection of the preferable parameters of the clasp arm. Results: Within the limitations of this study, the preferable cross-sectional shape of the retentive cast circumferential clasp arm was determined as half-round and the taper 0.6 mm.