How can the gingival areas be customised using infiltration liquids?
If gingiva sections of zirconia restorations are to be customised by staining, different options are available depending on the situation:
1. Use of light dentine shades for the gingival area a defined: bone-coloured lightness from deeper areas can be created by
applying light dentine stains in the gingival area before sintering and subsequent veneering using gingival porcelains.
2. Use of different gingival liquids: for this I like to use, for example gingiva, pink and blue-coloured Ceramill Liquids. Different
accents can be placed using these colours.
3. Of course, gingiva and dentine colours can also be combined with one another. For this the dentine shade is applied vertically
in the root area, i.e. towards the root. The gingiva liquid is applied in the interalveolar region.
(See gingiva in the second photo above: dentine liquid = red, gingiva liquid=green)
Which sintering programme is ideal for such solid restorations?
The choice of a slow sintering programme, ideally with integrated pre-drying programme, is always recommended with such solid framework structures. This is the only way to guarantee that no deformation or cracks occur in the material during sintering. If a pre-drying programme is not possible in the sintering furnace, the restoration must be dried out in advance in a suitable unit.
What should be observed with subsequent porcelain veneering of the restoration?
I recommend corresponding slow programmes with long-span bridges and also bridges with extended gingival areas. This reduces thermal stress in the material and prevents crazing and cracks. It is essential to follow the instructions for use of the respective porcelain manufacturer for slow programmes.
Veneering the gingival area with porcelain or composite?
Basically, the zirconia framework can be easily veneered both with porcelain and also composites. If a large amount of material is to be applied, composite veneering is often more advantageous. If porcelain veneering is used, additional firing cycles could result in thermal stress in the material. Another advantage of composite veneering is that it is easier to correct and repair. There is also the fact that the weight of a composite veneer is lighter than a porcelain veneer.