While having a dental bridge presents unique challenges for orthodontic care, it does not automatically prevent a person from getting braces. A dental bridge is a fixed prosthetic that replaces a missing tooth (pontic) by anchoring to the natural teeth on either side, known as abutment teeth. Braces are designed to apply controlled forces to move individual teeth through the jawbone. Successfully combining these two treatments requires extensive coordination and planning between the treating orthodontist and the restorative dentist.
The Structural Conflict: Why Braces Complicate Bridges
The primary difficulty in treating a patient with a fixed dental bridge is the fundamental difference in how the structures function. Orthodontic movement relies on the periodontal ligament, a soft tissue surrounding the tooth root, which allows the tooth to shift when light, continuous pressure is applied. A traditional bridge, however, fuses the pontic to the crowns placed over the abutment teeth, essentially locking these teeth together as a single, rigid unit.
Applying orthodontic force to a fused unit is problematic because the force is distributed across all connected teeth simultaneously. This can lead to uncontrolled tooth movement, a high risk of the bridge debonding, or structural failure of the prosthetic itself. Furthermore, the supporting abutment teeth were prepared and crowned to receive the bridge, and applying direct force to these already-altered teeth can heighten the risk of root resorption or damage to the underlying tooth structure.
The materials used for bridges, such as porcelain or gold, also complicate the process of affixing traditional orthodontic brackets. Standard bonding agents are designed to adhere to natural tooth enamel, not the smooth, non-porous surfaces of restorative materials. Specialized surface treatments are necessary to achieve a bond strong enough to withstand orthodontic forces, yet gentle enough to prevent damage when the brackets are eventually removed.
Specialized Orthodontic Techniques for Treatment
Orthodontists employ several specialized techniques to bypass the structural limitations presented by a fixed bridge. One common strategy is to avoid placing direct pressure on the abutment teeth entirely, focusing instead on localized tooth movement in other areas of the mouth. This approach isolates the teeth that need to be repositioned from the fixed bridge unit.
For anchorage, Temporary Anchorage Devices, or TADS, are frequently utilized to provide a stable point from which to move teeth. These small, temporary screws placed into the jawbone offer a fixed anchor that is independent of the natural teeth, allowing the orthodontist to move specific teeth without engaging the bridge or its abutment teeth.
In some cases, the original fixed bridge may be temporarily removed and replaced with a provisional, temporary restoration. This allows the orthodontist to move the abutment teeth slightly if necessary for overall alignment, or to apply brackets directly to the prepared abutment teeth surfaces.
When brackets must be placed on the bridge’s surface, the bonding process is significantly modified. For porcelain or ceramic surfaces, the procedure often involves micro-etching the surface with a weak hydrofluoric acid solution and applying a chemical coupling agent, such as silane, before the adhesive is used. These steps create microscopic roughness and a chemical link to ensure a secure attachment that can withstand the forces of chewing and orthodontic wire adjustment.
Post-Treatment Planning: Bridge Replacement
The original prosthetic will almost certainly require replacement after orthodontic treatment. Since braces change the alignment of the surrounding teeth and the position of the abutment teeth, the original bridge will no longer fit the new contours of the mouth once tooth movement is complete. The slight shift in the abutment teeth position means the fixed restoration will no longer be seated correctly.
After the braces are removed, a period of stabilization is required, during which the patient often wears a temporary retainer or provisional bridge. The soft tissues and bone surrounding the newly moved teeth need time to solidify in their final positions, which can take several weeks.
Following this stabilization phase, the restorative dentist takes new impressions of the corrected teeth. The final, permanent bridge is then custom-fabricated to precisely match the new dental alignment and bite. This new bridge is designed to fit the final positions of the abutment teeth, ensuring a stable and long-lasting restoration. The process typically involves a few appointments over two to four weeks, allowing for fabrication time in the dental laboratory.