Abstract: A growing demand is felt today for realistic 3D
models enabling the cognition and popularization of historical-artistic
heritage. Evaluation and preservation of Cultural Heritage is
inextricably connected with the innovative processes of gaining,
managing, and using knowledge. The development and perfecting of
techniques for acquiring and elaborating photorealistic 3D models,
made them pivotal elements for popularizing information of objects
on the scale of architectonic structures.
Abstract: Cast metal inlays can be used on molars requiring a
class II restoration instead amalgam and offer a durable alternative.
Because it is known that class II inlays may increase the
susceptibility to fracture, it is important to ensure optimal
performance in selection of the adequate preparation design to reduce
stresses in teeth structures and also in the restorations. The aim of the
study was to investigate the influence of preparation design on stress
distribution in molars with different class II preparations and in cast
metal inlays. The first step of the study was to achieve 3D models in
order to analyze teeth and cast metal class II inlays. The geometry of
the intact tooth was obtained by 3D scanning using a manufactured
device. With a NURBS modeling program the preparations and the
appropriately inlays were designed. 3D models of first upper molars
of the same shape and size were created. Inlay cavities designs were
created using literature data. The geometrical model was exported
and the mesh structure of the solid 3D model was created for
structural simulations. Stresses were located around the occlusal
contact areas. For the studied cases, the stress values were not
significant influenced by the taper of the preparation. it was
demonstrated stresses are higher in the cast metal restorations and
therefore the strength of the teeth is not affected.
Abstract: The study of the generated defects on manufactured
parts shows the difficulty to maintain parts in their positions during
the machining process and to estimate them during the pre-process
plan. This work presents a contribution to the development of 3D
models for the optimization of the manufacturing tolerances. An
experimental study allows the measurement of the defects of part
positioning for the determination of ε and the choice of an optimal
setup of the part. An approach of 3D tolerance based on the small
displacements method permits the determination of the
manufacturing errors upstream. A developed tool, allows an
automatic generation of the tolerance intervals along the three axes.