Failed crowns, bridges, implants and veneers

Why dental work fails

Restorations rarely fail for one reason alone. The most common causes are:

• Bite forces. Clenching and grinding put far more load on teeth and implants than chewing does, and a bite that is slightly off concentrates that load on a single crown.
• Decay at the edges. New decay can form where a crown or bridge meets the tooth, often unseen until the tooth underneath is badly damaged.
• Gum and bone health. A restoration is only as stable as the gum and bone around it. Gum disease can loosen teeth and implants that were well made.
• Design and material. A material that is too thin, too brittle or wrong for the bite will chip or crack, and a shape that cannot be cleaned will invite disease.
• Implant factors. An implant placed where the final tooth cannot be restored well, a loose abutment screw, or inflammation in the surrounding bone can each produce a failing implant crown.

Signs that deserve a specialist’s look

• A crown or bridge that has come off more than once
• Porcelain that chips or fractures repeatedly
• Decay or dark lines at the edge of an old crown
• An implant crown that is loose, clicks or has a screw that keeps loosening
• Bleeding, swelling or a bad taste around an implant
• Pain when biting, or food that packs under a bridge
• Veneers that are lifting, staining at the edges or no longer match the bite

How the cause is found

The assessment looks at the whole system, not only the failed tooth. It usually includes a clinical examination, an analysis of the bite, current X-rays, and a cone beam CT when bone or implants are involved. It helps to bring earlier X-rays and treatment records if you have them, because they show what has changed over time.

What happens next

Treatment follows the diagnosis. Depending on the cause, the plan might mean treating the gums first, adjusting the bite, protecting the teeth with a night guard, remaking a restoration with a different design or material, or replacing a failing tooth with an implant. Sometimes the right answer is to monitor a restoration and do nothing yet. The options, including the option of doing less, are explained before anything is started.