A dental bridge is a fixed prosthetic restoration designed to replace one or more missing teeth by anchoring an artificial tooth, known as a pontic, to the natural teeth on either side of the gap. These anchoring teeth, called abutments, are covered with crowns that support the entire structure, restoring both function and appearance. While a bridge is a durable solution, it is not permanent, and replacement is a common necessity to maintain oral health. The average lifespan for a fixed bridge ranges from five to fifteen years, meaning that nearly every patient with a bridge will eventually need to consider replacement.
Why Dental Bridges Require Replacement
The need for replacement often stems from issues compromising the integrity of the supporting abutment teeth or the bridge material itself. Recurrent decay (dental caries) is a primary cause of failure, occurring at the margins where the crown meets the natural tooth structure. If the seal fails, bacteria can leak underneath the crown, causing decay in the prepared abutment tooth that may be difficult to detect without X-rays.
Abutment tooth failure is another significant reason for replacement, such as a fracture beneath the crown or the development of a root canal issue. The materials of the bridge can also fail over time, leading to chipping of the porcelain or fracture of the prosthetic structure, often due to heavy biting forces or grinding habits. Furthermore, gum recession can expose the bridge margins, leading to poor aesthetics, food trapping, and a compromised fit.
Initial Steps: Assessment and Removing the Existing Bridge
Replacing a bridge begins with a clinical assessment to determine the reason for failure and the viability of the underlying abutment teeth. The dentist takes new radiographs (X-rays) to evaluate bone support and check for signs of infection or decay around the roots. Abutment teeth must be healthy enough to support a new restoration; otherwise, alternative treatments like dental implants may be necessary.
Once the abutment teeth are deemed sound, the existing bridge must be carefully removed, often by sectioning the restoration with a dental handpiece. This requires precision to avoid damaging the underlying tooth structure, especially if the abutments are compromised. After removal, the supporting teeth are cleaned, and any decay is removed and restored with a dental filling material.
The abutment teeth are then re-prepared, involving resurfacing or re-shaping them to create the ideal dimensions and contours for the new bridge. This ensures the new restoration will have a precise marginal fit and sufficient thickness for the chosen material. Following re-preparation, a cord is placed around the teeth to push the gum tissue away slightly, allowing for an accurate impression of the prepared margins.
Fabricating and Placing the New Bridge
After preparation is complete, the dentist captures an impression of the prepared area, often using physical material (polyvinyl siloxane) or a modern digital intraoral scanner. This impression serves as the blueprint for the dental laboratory, where technicians custom-fabricate the permanent bridge. The dentist selects the color and material, which may include porcelain fused to metal, high-strength zirconia, or all-ceramic options, depending on the location and aesthetic demands.
During the one to three weeks required for the lab to manufacture the permanent bridge, a temporary restoration is cemented onto the prepared abutment teeth. This provisional bridge protects the newly shaped teeth from sensitivity and shifting, while maintaining the patient’s ability to chew and speak. The temporary bridge is easily removed at the subsequent appointment when the permanent restoration is ready.
The final appointment involves removing the temporary bridge and trying in the new permanent restoration to confirm its fit, bite alignment, and aesthetic appearance. Minor adjustments to the contours or bite surface may be necessary at this stage to ensure comfort and proper function. Once the patient and dentist are satisfied with the final result, the bridge is permanently cemented onto the abutment teeth using a strong, biocompatible dental cement.
Financial Considerations and Post-Procedure Care
The financial commitment for replacing a dental bridge is variable, influenced by factors such as the number of missing teeth, case complexity, and materials selected. Costs for a traditional bridge can range widely and may not include necessary preliminary procedures like treating decay or performing a root canal on an abutment tooth. Dental insurance often covers a percentage of the cost, typically between 50% and 80%, which can reduce the out-of-pocket expense.
The overall treatment timeline typically spans three to six weeks, encompassing multiple appointments from initial removal to final cementation. Maximizing the lifespan of the new bridge requires consistent, specialized post-procedure care, focusing on hygiene around the artificial tooth and its connection to the abutments. Patients must use specialized flossing aids, such as floss threaders or a water flosser, to clean the area beneath the pontic where a regular toothbrush cannot reach. Regular dental checkups and professional cleanings are necessary to monitor the health of the abutment teeth, gum tissue, and bridge margins.