A dental bridge is a fixed restoration designed to replace a missing tooth by “bridging” the gap in your smile. This prosthetic device consists of an artificial tooth held in place by crowns attached to the natural teeth on either side of the space. A cantilever bridge is a specific type of dental bridge that is distinguished by being supported on one side only, using a single tooth next to the gap for its anchor. This design offers a unique solution when a traditional two-sided bridge is not possible.
Defining the Cantilever Bridge Structure
The cantilever bridge is composed of two structural elements: the pontic and the abutment. The pontic is the artificial tooth that fills the space where the natural tooth is missing, and it is crafted to match the color and shape of the surrounding teeth. The abutment is the natural tooth or teeth adjacent to the gap that provides the necessary support for the restoration. In a cantilever design, the pontic is attached to the abutment on only one side, meaning the replacement tooth extends out over the space. This single-sided connection requires the abutment tooth to be prepared and fitted with a crown to securely hold the pontic.
Ideal Placement Scenarios
This type of bridge is often recommended when a healthy natural tooth is only present on one side of the space requiring replacement. A cantilever design is particularly well-suited for replacing a missing tooth in the anterior, or front, part of the mouth. The biting forces in the front are much lighter compared to the back, making a single abutment support more feasible. For example, a common application is replacing a small upper lateral incisor, using the stronger adjacent canine tooth as the sole abutment. Conversely, this design is avoided in the posterior region, where chewing forces exerted on molars can be up to 200 pounds of pressure.
Long-Term Stress and Potential Issues
The unique, single-sided support system creates a mechanical disadvantage for the restoration over time. Forces applied to the unsupported pontic act as a lever, generating increased and uneven stress on the single abutment tooth. This mechanical action is referred to as torque, which causes a rotational force on the anchor tooth. This excessive strain can lead to several long-term complications, including the abutment tooth loosening or fracturing. The single point of attachment also makes the bridge more susceptible to failure, such as the restoration loosening or debonding from the supporting tooth.
Care and Alternatives
Maintaining a cantilever bridge requires diligent oral hygiene, with special attention paid to the area beneath the pontic and around the abutment tooth. Since a regular floss strand cannot pass through the connection, specialized tools like floss threaders or superfloss are necessary to clean the underside of the artificial tooth and prevent decay on the supporting tooth. Brushing and flossing daily, along with regular professional checkups, helps monitor the health of the abutment and the integrity of the bridge.
Alternatives to Cantilever Bridges
If a cantilever bridge is not the best option, alternatives are available for replacing a missing tooth. The traditional fixed bridge requires healthy teeth on both sides of the gap to act as dual abutments for greater stability. A dental implant is often considered the gold standard, as it replaces the tooth root with a titanium post, which avoids placing any stress on the adjacent natural teeth.