Another Solution for Single-Tooth Ectopias

Clear aligners utilize bonded attachments to help retain the trays and to facilitate individual tooth movements (Fig. 1). The computer-generated attachment setup must be precisely reproduced at the chair using flexible templates and composite resin.

The main clinical problem when placing composite in the small attachment windows of the template is the creation of voids, which may cause attachment surface changes or fractures.¹ A second challenge is the removal of excess flash around the bonded attachment, which may go unnoticed if the composite is enamel-colored. Removing excess flash can be difficult to do without damaging the active attachments.² If left unaddressed, however, excess adhesive can lead to tooth discoloration, plaque retention, or white-spot lesions,³ as well as poor seating of the aligners and the need for extra force when removing the trays.

This article presents a simple technique that can eliminate voids, minimize flash, and facilitate the safe removal of flash from around bonded attachments.

Procedure

1. Test the flexible attachment templates and the first aligner trays in the mouth to ensure that the aligners snap into place and fit properly in both arches.

2. Verify the location and size of the required attachments in the templates.

3. Load the uncured color-changing composite resin^** into the windows of each attachment template (Fig. 2A), slightly overfilling the attachment windows. Use a condenser to apply gentle pressure over the uncured composite, ensuring that the composite will flow evenly into the attachment windows. Inspect the facial surface of the template to be sure there are no voids (Fig. 2B). Compress the composite so that the exposed surface is level with the edges of the attachment windows; this will minimize flash (Fig. 2C). Place the attachment template with the uncured composite in a light-sealed box.

5. Fully seat the template loaded with the uncured composite. The pink color of the uncured composite will make it easier to see any excess flash around the attachment template (Fig. 3).

6. Use an instrument to apply gentle pressure around each attachment to ensure full adaptation of the template. After curing the composite, remove and save the attachment template, then light-cure again.

7. To clean the residual flash from around the attachments, first outline the attachments with a sharp pencil (Fig. 4A). Next, create a contrast between the tooth surfaces and the cured flash around the attachments by wiping the attachments with articulating paper² (Fig. 4B).

8. After the interproximal areas have been flossed, the aligners are ready for patient use. Attachments bonded according to this procedure will closely match the computer-generated setup (Fig. 5).

Discussion

Because the pink color indicator incorporated into the composite becomes activated when exposed to a light source, it helps the clinician to identify any voids through the transparent aligners, as well as to remove excess flash from around the attachments. Outlining the attachments further reveals residual flash for clean-up, thus saving the additional chairtime that could be required to remove tooth-colored composite and avoiding damage to the attachments.