We do not recommend treating patients with dental prosthetics and implants (such as crowns, bridges, dentures and implants) because:
- Crowns usually can't support engagers.
- Bridges also usually can't support engagers. They can create too much retention, making it difficult to remove the aligner, and because they're anchored to other teeth, they usually impair the movement of multiple teeth in an arch.
- Dentures are designed to fit together with the opposing natural arch. If any teeth move, the dentures will probably need to be replaced or adjusted.
- Even partial dentures will most likely need to be replaced, because shifting even a few teeth in an arch can cause other teeth to move, as well. Also, making aligners over partial dentures can create very odd surfaces that will affect the manufacturing process.
- Implants cannot be moved because they are fused to the bone. Putting an aligner on an implant might cause the implant to fail if too much force is applied.