Incisal tips through the window

The prevalence of toothwear is increasing in both adolescent and adult populations.^1,2,3 A popular approach for the management of toothwear is to utilize direct composite resin.^4,5,6,7 This minimally invasive technique restores natural form, function and aesthetics by preserving tooth substance and sustaining tooth vitality.

The previous publication focused on using a putty matrix for the restoration of worn maxillary incisor teeth. Many cases also display wear of the mandibular incisor teeth and these present different challenges. Publications have described alternative techniques to the putty index, most notably the vacuum-formed matrix.⁸ However, a common problem encountered with the vacuum-formed matrix is excess composite material flowing into proximal spaces and bonding adjacent teeth together, both of which exponentially increase time for finishing.

This follow-up paper describes a modified method of using a vacuum-formed matrix to circumvent such issues, producing fast predictable composite resin build-ups.

As mentioned previously, a full history, examination, diagnosis, and preventive course of treatment is first required.⁹ Subsequently, a wax-up can be prescribed on mounted study casts.

Figure 1 shows the pre-operative clinical situation. Once the clinician is happy with the wax-up (Figure 2), the laboratory duplicates the wax-up in stone to fabricate the 0.5 mm hard acrylic vacuum-formed matrix (Figure 3). As seen in Figure 3, the matrix covers the entire labial surface of the incisors beyond the gingival margin. This prohibits the clinician from accurately judging the quantity of composite resin to put in the matrix, and the removal of excess flash from proximal areas before curing. An alternative technique is described:

To modify the matrix the clinician should place the matrix back on the wax-up and mark on the labial surface where the wax begins (Figure 4);

Then, taking a scalpel or pair of sharp scissors, cut along this line on the matrix to create a window in the labial surface (Figure 5). This has accomplished two things, it acts as a guide to the quantity of composite required, reducing wastage, and allows the clinician access to the proximal areas, thereby preventing the teeth from bonding together;

Disinfect the matrix and check the fit in the patient's mouth (Figure 6).

Using appropriate moisture control and separation, begin tooth conditioning to receive the composite resin;

Fill the matrix as required and place it on the teeth (Figure 7);

With a wards carver remove any excess and curing appropriately (Figure 8);

Remove the matrix and carry out any finishing being careful not to cause gingival bleeding (Figure 9);

Repeat the process until all the incisors have been restored (Figure 10);

Finally, use articulating paper to check for even occlusal contacts, canine guidance and carry out final polishing.

One drawback of this technique is that there is no capacity to layer the composite resin to recreate incisal characterization. However, Figure 11 shows that it can repeatedly produce clinically adequate results.