In dentistry, three-dimensional reconstructions after computed tomographies are used in traumatology and implantology. The aim of the study was to achieve three-dimensional reconstructions after computed tomographies, in order to obtain faithful models which can be used for numerical simulations of the teeth and prosthetic restorations. Because of the small dimensions and high complexities used in dentistry, it was necessary to obtain enlarged radioopaque models. Axial slices of 1 mm were made. Resulted images were transformed into curves and these in point clouds. The points were used to get a network and than for surfaces and solids, necessary for numerical simulations. The faithfulness of the solids depends on the structural complexity, the aggrandizement degree and the images processing procedures. Three-dimensional reconstructions of complex prosthetic restorations is difficult to obtain using computed tompographies. Keywords: three-dimensional reconstructions, computed tomographies, teeth, prosthetic restorations