Incisal Halo

Incisal edges are optically complex areas with strategic light dynamics. In this area, prisms converge in a particular way, creating extraordinary optical effects.

Fig.1

Composite failure of a recently done incisal lengthening, probably due to a poor adhesive technique. As one of the most important color characteristics that we will need to copy from this tooth (11) is the incisal halo.

Fig.2

One of the most important steps in restorative dentistry is the field isolation, done carefully, invaginating the rubber dam perfectly to avoid infiltration and to have full vision of the teeth we will work on.

Fig.3

With a medium grit abrasive disc, the invisible composite excess is removed completely, and unsupported prisms are flattened with a very delicate touch in order to respect the sound enamel. These kinds of discs consume very efficiently the composite and have very little action on the enamel.

Fig.4

With an abrasive rubber tip, the preparation is polished in order to have an ideal surface to etch, more efficiently than having irregular prisms on a rough surface.

Fig.5

Etching is performed with orthophosphoric acid for 30 seconds.

Fig.6

Rinse the acid gel for 30 seconds and then the cavity is dried with air indirectly (not aiming to the dentin directly).

Fig.7

The bonding procedures are performed, bonding agents were applied, thinned with air and polymerized for 20 seconds.

Fig.8

In the same way, a second layer of adhesive is applied and cured for one minute, in order to achieve the best possible degree of conversion of the most important layer, the hybrid layer.

Fig.9

The palatal wall is built with an enamel mass with the aid of a palatal silicone key, previously obtained from a mock-up done directly in the mouth.

Fig.10

After the palatal wall is finished, a correction can be done with a diamond bur at low speed and without water in order to achieve a very precise shape. It is very important not to touch the tooth.

Fig.11

One shall not worry about the dust generated, which is very easy to remove. With the brush moistened in a pure photo curing resin, the cavity is fully impregnated and then the excess of adhesive is blown off with plenty of air directly. The cavity will be decontaminated again.

Fig.12

TIP
With the chosen dentin for the overall tooth color, an incisal halo will be modeled with the same dentin, these are proven to be the best masses for this effect, due to their natural opacity and light transmission properties. In other words, an opaque dentin will be used to build up the tooth in an area where the enamel is physically very transparent but optically very opaque.

Fig.13

The dentinal body is placed, in this case, very small, but of extreme importance. Is mandatory to not cure in order to be able to carry on the next step.

Fig.14

With the un-cured dentin, the “LM Arte Misura” instrument is passed along the whole margin in order to detect lack or excess of material, leaving a perfect 0.5 mm spacing for the final enamel layer. With this kind of instrument, it is possible to place the dentin in a bulk way and then remove the excess in a very simply and quickly (picture edited for educational purposes).

Fig.15

The final layer of enamel is stratified occupying as well the opalescent area.

Fig.16

Finishing of the surface with a multi-blade bur.

Fig.17

Polishing is done with fine grit rubber tips and a goat brush (Micerium, Italy) with diamond paste (Diamond twist, Premiere USA), and finally with Astrobrush (Ivoclar, Lichtenstein) with plenty of water.

Fig.18

The restoration finished, and we’re ready to remove the dental dam and occlusion check.

Fig.19

After rubber dam removal and occlusion check, Astrobrush was again used and the patient was asked to come back in one month.

Fig.20

Check-up after a month, shows the teeth already rehydrated and the composite perfectly blended. Showing how a simplified two layer technique can achieve polychromatic results and even a complex structure such as an incisal halo with only two colors.

Fig.21

Before.

Fig.22

After.

Bibliography

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