The dynamic behaviour of a lower complete denture during unilateral loads: analysis using the finite element method.

The purpose of this study was to analyse the correlation between the location and/or direction of unilateral load and the dynamic behaviour of a mandibular complete denture using the three-dimensional finite element method (FEM). The FE model consisted of the body of mandible, alveolar mucosa, and a complete denture, and it could simulate the condition of contact between the surface of the mucosa and mucosal surface of a denture. Load vectors, which simulated premature contacts, were calculated on the supposition that a premature contact on an occlusal facet causes a vertical load on it. Load-A, a load vertical to the anterior occlusal facet, caused the least displacement of the denture and less concentrated stress distribution. Load-P, a load vertical to the posterior occlusal facet, was characterized by the stress distributed in the lingual area of the pre-molar lesion on the contra-lateral side of the load. Load-B, a load vertical to the balancing occlusal facet, caused the largest displacement of the denture. The relationship between loads and stress distribution was agreed approximately with the observations previously reported, and lead to some suggestions about occlusion for complete dentures.