Shade characteristics of natural teeth

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A metal core will always work against us, because it will block light transmission thus creating dark areas in the internal layers of the teeth, which results in a higher opacity in the exterior layers of the crown. If a metal core has to be used, it is imperative to create a ceramic shoulder. The picture clearly illustrates how the metal substructure is blocking the light, while the light passes freely through the other areas until it reaches the preparation, thus creating a soft transition area that favours the integration of the restoration. In this Special Edition, we will identify the different shade characteristics that are present in natural teeth and explain a step-by-step procedure to reproduce these characteristics using ceramic materials. 2
White, orange and brown enamel cracks We can observe this shade characteristic quite frequently in the dental enamel of adjoining teeth. The shade and appearance of enamel cracks vary. While the shade variation does not present that much of a problem, its influence on the appearance of the restoration appears to be more of a difficulty. The appearance of an enamel crack or fissure changes in response to the light refraction angle. In other words, if an enamel crack is exposed to frontal light, it Fig. 1a looks like a fine, clearly defined line (Fig. 1a). If, in contrast, the enamel crack is exposed to lateral light, light refraction is more pronounced (Fig. 1b). Virtually all natural enamel cracks Fig. 1b are located in the enamel. Therefore, the corresponding shade characteristic of a restoration should be created in the same area, i.e. in the final layer of the layering pattern, when the underlying layers have already been covered with a translucent material. It is very important to use the entire thickness of the translucent layer to reproduce the fissure, since this will provide it with a three-dimensional, true-tonature appearance. If we limit ourselves to staining only the intermediate layers, the enamel crack will demonstrate a twodimensional appearance and thus not correspond to the natural model. The enamel crack is created after the internal layering has been built up to the point at which only the translucent material has to be applied to complete the morphology. At this stage, the dentin, incisal and other shade characteristics have already been built up. The next step is to build up the morphology of the tooth using Transpa neutral. The layer should extend to the area where the enamel crack is to be placed. 3
Page 1: Shade characteristics of natural te
Page 5 and 6: Here, however, the crack is created
Page 7 and 8: The same technique can be applied t
Page 9 and 10: The tooth morphology is now complet
Page 11 and 12: Abrasion of the incisal edge Abrasi
Page 13 and 14: If the mamelons need to be more pro
Page 15 and 16: Shade characteristics of our patien
Page 17 and 18: When an entire anterior group of te
Page 19 and 20: Initial situation before treatment.
Page 21 and 22: Crown after having been cemented in
Page 23 and 24: Descriptions and data constitute no

Shade characteristics of natural teeth

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