Clinical review required: A crown can lose retention, chip, fracture, develop decay at its margin or become painful while the tooth beneath remains treatable. Facial swelling, fever, trauma with uncontrolled bleeding, difficulty swallowing or a crown associated with severe escalating pain needs urgent assessment.

What does a failed crown mean?

A dental crown is considered failed when it no longer protects the tooth, provides acceptable function or can be maintained safely. Failure is not a single diagnosis. A crown may be intact but loose; the ceramic may chip while the framework remains sound; or the restoration may look normal while decay, pulpal disease or root fracture develops beneath it. The remedy depends on the cause and the condition of the supporting tooth.

Common signs

Warning signs include movement, a visible crack, sharp edge, food trapping, persistent bad taste, bleeding at the margin, bite pain, temperature sensitivity, spontaneous ache or swelling. A dark line can be exposed metal, stain, shadow or decay and cannot be diagnosed from appearance alone. Some recurrent decay is found only during examination or radiography.

A loose or detached crown

Loss of retention can follow cement breakdown, inadequate tooth height, new decay, contamination, poor fit or heavy forces. Recementation is reasonable only when the crown fits accurately, the tooth is sound and the cause can be controlled. Repeatedly recementing a poorly fitting crown may hide decay or allow further tooth damage.

What to do if the crown comes off

Keep the crown, rinse it gently and arrange prompt dental care. Avoid chewing on the tooth and protect it from very hot, cold or hard foods. Do not use superglue or other household adhesives. Temporary dental cement may be unsuitable if the bite or orientation is uncertain, and forcing a crown into place can create aspiration, swallowing or tooth-fracture risk.

Decay beneath or beside a crown

Crowns do not make teeth immune to caries. Plaque retention, an open or overhanging margin, exposed root surface, frequent sugar intake and dry mouth can contribute. Small accessible lesions may occasionally be repaired, but decay extending beneath the crown often requires removal to see whether the tooth is restorable. Prevention includes fluoride exposure, interdental cleaning and management of dry mouth and diet.

Chipping and fracture

A small ceramic chip can sometimes be polished or repaired with composite. Larger fractures may expose a framework, disturb contact or bite, or indicate inadequate material thickness and overload. A split crown, framework fracture or damage combined with poor fit generally favours replacement. The clinician also looks for grinding, opposing materials and design factors so the next restoration does not repeat the same failure.

Pain after a crown

Short-lived sensitivity can occur after tooth preparation or cementation. Persistent cold pain, spontaneous ache, pain on biting or swelling requires diagnosis. Causes include a high bite, reversible or irreversible pulpal inflammation, a crack, cement irritation, periodontal inflammation or an adjacent tooth. Root-canal treatment should be based on pulpal and apical findings, not performed automatically because a crowned tooth hurts.

Root fracture and restorability

A crown may loosen because the core or tooth has fractured. The dentist evaluates remaining walls, ferrule, decay depth, root length, periodontal support and crack direction. Crown lengthening or orthodontic extrusion can expose sound tooth structure in selected cases, but each changes the gum, bone, timing and aesthetic result. A vertical root fracture or deep non-restorable decay may require extraction.

Gum inflammation and recession

Overcontoured crowns, inaccessible margins, residual cement and poor contact can retain plaque. Recession can expose a root or crown edge and create a colour mismatch without proving decay. Treatment may involve hygiene access, contour adjustment, replacement, periodontal care or selective tissue procedures. Simply extending a new margin deeper under the gum can worsen inflammation.

Bite and contact problems

A crown that feels high can cause tenderness, mobility or muscle discomfort. An open contact may trap food and irritate the papilla; an overly tight contact can prevent cleaning. Adjustment is conservative when the crown otherwise fits, but excessive grinding can weaken ceramic or destroy anatomy. Major positional or contour errors may require remaking the crown.

Aesthetic failure

Colour, translucency, shape, surface texture, gum level and symmetry all affect appearance. A mismatch does not necessarily mean biological failure, but replacement removes additional material and carries pulpal and fracture risk. Photographs, shade records and a diagnostic preview help distinguish correctable polishing or contour issues from a crown that genuinely needs replacement.

How failure is diagnosed

Assessment includes symptom history, visual and tactile margin checks, mobility, percussion, bite testing, periodontal probing, pulp tests where meaningful and radiographs. Existing images help identify change. No single test shows every crack or margin. Removing the crown may be the only way to inspect decay or the core fully, and the crown may not survive removal.

Repair, recementation or replacement?

Polishing suits minor roughness. Composite repair may manage a local chip. Recementation needs a sound tooth and accurate restoration. Replacement is more appropriate for extensive fracture, poor margins, recurrent decay, unacceptable contours or compromised structure. The least invasive option that produces a cleansable seal and stable bite is preferred, but a temporary patch should not be presented as a permanent solution.

When root-canal treatment is needed

If the pulp becomes irreversibly inflamed or infected, endodontic treatment may preserve a restorable tooth. Access can sometimes be made through the crown; in other cases removal improves inspection and restoration. Root-canal treatment does not repair decay, a leaking margin or root fracture, so the final coronal plan must be established first.

If the tooth cannot be saved

Extraction may be considered for a split tooth, non-restorable decay, severe periodontal loss or an unfavourable root fracture. Replacement choices include implant, bridge, removable prosthesis, orthodontic space closure or accepting the space. These have different biological costs. Extraction and immediate implant placement should not be assumed before imaging, infection and bone conditions are assessed.

Preventing another failure

Daily cleaning at the crown margin, fluoride, control of sugar frequency, regular review and early attention to looseness are central. A night guard may protect selected patients with bruxism but does not correct a poorly designed restoration. Material choice should follow tooth position, preparation, available thickness, bonding conditions, appearance and load rather than marketing labels alone.

Treatment abroad and records

Request pre-treatment and final radiographs, tooth vitality or root-canal status, core and post details, preparation scan, crown material, cement or bonding protocol and laboratory prescription. Confirm how bite, contact, shade and margin problems will be assessed after travel. A replacement warranty may exclude the clinical work needed beneath the crown.

Questions to ask

Has the crown failed, the tooth failed, or both?
Is decay or fracture present beneath it?
Can it be removed without destroying it?
Would repair or recementation provide a durable seal?
Is the tooth restorable before a new crown is made?
What caused the problem and how will recurrence be reduced?

Frequently asked questions

Can a fallen crown be reused?

Sometimes, if it fits and both crown and tooth are sound. It requires clinical assessment.

Does a crown always need root-canal treatment?

No. Endodontic treatment is based on pulp and apical diagnosis.

Can a chipped crown be repaired?

Small, favourably located chips may be polished or bonded; larger structural failures often need replacement.

Why does a crown smell?

Food trapping, plaque, an open margin, decay or gum inflammation may contribute and should be examined.

Sources and clinical review references

Editorial review note: Evidence reviewed 22 July 2026. Named clinician review is required before indexation.

Failed Crown