REPRODUCING NATURE
Luana Tito shares how to interpret the patient’s mucosa in order to achieve a natural characterisation of a dental prosthesis Leave a comment
In order to achieve the natural characterisation of a dental prosthesis, it is necessary for the technician to have a basic understanding of the internal structures they’re trying to replicate.
Only then can they achieve a more natural approximation in the prosthesis according to the colour of the patient’s gums. We need to understand how to interpret the patient’s mucosa. For example, we notice that the colours are more intense with vivid shades in areas like the alveolar mucosa, but in regions like the free gingiva or frenum, we observe softer tones. By training our eyes to interpret mucosa colours, reproducing them becomes easier.
In Brazil, we use the salt and pepper characterisation method. For this we use different shades of pink, dentin colour, and intensive pigments. The colours to be used vary greatly from patient to patient. There’s no ready-made recipe; an analysis is always done to understand what each shade represents.
LAYER BY LAYER
When starting the characterisation, the first thing we do is reproduce the veins by placing wool in the alveolar mucosa region. We must ensure that the wool is of good quality and doesn’t release dye. To determine its quality, you can immerse a piece in monomer for a few minutes; if it doesn’t release colour, it can be used.
The next step involves applying a thin layer of resin to give our piece a skin colour. It is important that the first layers are always thin, so the effect of the subsequent layers becomes visible. With that said, we apply lighter colours around the teeth, allowing the resin to flow slightly into other areas to create a smooth gradient between colour layers, thus adding naturalness to the piece.
In the area of the mucogingival junction, we start with a stronger tone. We finish in alveolar mucosa with intense colours. To mimic the bony plate tones, I use dentin colours, placing them where the roots would be, always paying attention to each volume. I also use a bit of the same intensive colour used in alveolar mucosa before, applying it very cautiously between the roots to create differentiation between layers, imitating the periosteum and adding depth to the characterisation.
After completing these steps, we redo the same process to the second layer, reapplying the veins and following the previous steps, always considering the space we have for this characterisation. A third layer could be necessary.
FINISHING
To finish, we cover the characterisation with a thin layer of resin and place a separating plastic to prevent resin from contacting the plaster, close the flask to check if the amount is appropriate or the excess needs to be cut off. In Brazil, it is very common for the palate of our prosthesis to be colourless. Therefore, after checking the resin space, we isolate our plaster to then complete our prosthesis with colourless resin.
When acrylicising with this method, a homogenisation time is necessary before proceeding with the polymerisation of the prosthesis. The time can vary from company to company.
