[Influence of escape channels (vents) in reproduction of occlusal contacts and external surface of complete cast metal crowns]. / Influência nos condutos para escape de ar (ventings) na reprodução dos contactos oclusais e superficie externa de coroas totais metálicas fundidas.

The purpose of this investigation was to verify the influence of ventings on the reproduction of interocclusal contacts from the wax pattern to the cast crown and also to note the influence on surface quality. Comparatively were performed tests with no venting, with one joined on the outside of the full crown wax pattern and two ventings joined on the sprues (Fig. 2). The castings were obtained with a nickel-chrome alloy and investing was performed with phosphate bonded investment. From the results it was possible to conclude: casting without venting presented higher frequency of no reproduction of interocclusal contact points; when using one venting, joined on the outside of the crown wax pattern, the reproduction of the interocclusal contacts was 100%, the venting did not lead to high improvement on the surface quality.