Everyday Challenge: Composite Restoration

A 25-year-old female patient presented at the dental practice for a routine check-up. She went to the dentist regularly and had no complaints. Bitewing radiographs were taken to diagnose caries. This revealed an insufficient filling on the mesial occlusal surface of tooth 26, which continued into the proximal region (Fig. 1), which was not immediately apparent on visual inspection (Fig. 2). The cold test was clearly positive. The patient was therefore informed about renewal of the filling on tooth 26.

The treatment started with anaesthesia of the working area. The working area was then isolated with a heavy-gauge rubber dam (Isodam heavy 6x6). The master clamp is positioned as far distal as possible. In principle, a large isolation field is preferable for this type of treatment (sextant or quadrant isolation). An important step in isolation is punching the perforations in the rubber dam. A marking template is a useful tool for this. However, the perforations should not be too large, as this would make sufficient inversion considerably more difficult.

After application of the rubber dam, it was inverted at the tooth neck. This measure serves to seal the working area against liquids. Isolation is not complete without adequate inversion. Various techniques are available for this purpose. In this case, ligatures made of Gorilla Floss (very high stability and sturdiness) were chosen. These ligatures not only ensure inversion, but also retraction of the gingiva. This makes it much easier to restore deep cavities – as in this case.

After removing the old filling, the cavity became visible (Fig. 3). This could now be extended in a minimally invasive manner while preserving the substance. In the process, undermining enamel portions were only removed until all carious dentine was accessible with the rose bur. After caries removal, the cavity was cleaned with the sandblaster (28 μm aluminium oxide) (Fig. 4). This procedure removes the resulting debris and improves the adhesive bond.

When inserting the matrix, make sure that it is not deformed. Only an optimised emergence profile ensures good hygiene. In cases like this, deep margin elevation is often necessary to guarantee optimum emergence. With deep margin elevation, the deep part of the cavity is built up first using a special matrix. The contact point is then restored using a normal matrix. The procedure works very well with consistent isolation, but takes more time as two work steps are necessary.

Without deep margin elevation, the wedge for fixing the matrix could deform it and thus severely impair emergence. However, in this case the more time-consuming deep margin elevation was avoided and a plastic wedge (Palodent V3 large wedge) was used instead to fix the matrix (Fig. 5). This does not deform the matrix, but still fixes it sufficiently. Unfortunately, the teeth are not separated as much by the plastic wedge. Separation is therefore carried out using the clamping ring (do not use clamping rings that are too worn!). Using the plastic wedge therefore saved time in the case shown.

Finally, the cavity was conditioned and bonded using the acid-etching technique (in the case shown, with Optibond FL). The restoration was carried out according to a tried and tested procedure:

• Step 1: Reconstruction of the marginal ridge with Estelite Asteria NE (Tokuyama Dental);
• Step 2: Dentine replacement with Estelite Asteria A3B (Tokuyama Dental);
• Step 3: Cusp-by-cusp technique of the central cusp slopes with Estelite Asteria OcE (Tokuyama Dental);
• Step 4: Supplementation of the peripheral morphology with Estelite Asteria WE (Tokuyama Dental)
• Step 5: Colouring the fissures with Inspiro Fissure (EdelweissDR).

Once the composite layering was completed, the entire restoration was cured again under glycerine gel. This removes the oxygen inhibition layer. This significantly improves polishability and considerably increases durability. After removing the excess composite, the restoration was pre-polished (EVE Rotary Twist System). The desired high gloss was finally achieved with goat hair brushes (Fig. 6 and 7).

It is often the seemingly small, simple things that are full of surprises. Who would have thought that the patient, who had not complained of any symptoms, would have such an extensive lesion? Unfortunately, the bonding of the initial restoration was not sufficient to adequately seal the cavity.

In order to be able to achieve a good and, above all, long-term stable result for such lesions, it is therefore necessary to observe certain things such as carefully sealing the working area against liquid, attaching adequate ligatures for inversion, as well as preparation that is gentle on the substance but still practicable and the correct use of the matrix – not to forget etching and bonding lege artis as well as the restoration of the defect with the appropriate composites.

In this way, a composite restoration was achieved on tooth 26 that is not recognisable as such and absolutely fulfils its task of preserving the tooth and concealing the defect (Figs. 8 and 9).