Crowns or Veneers Gone Wrong: What Can Happen and What Can Be Done

What can go wrong, and how often

The figures below come from studies of groups of patients. They tell you what is common and what is rare; they do not tell you what will happen to your teeth.

• Cracks, chips and fractures. A meta-analysis of ceramic veneers followed for an average of 10.4 years found cracks in 4.3 in 100, small chips in 3.5 and complete fractures in 2.5³. The differences between studies were large. Not every crack or small chip means the veneer must be replaced.
• Coming off. In the same meta-analysis, about 2.2 in 100 veneers came off. Veneers bonded mostly to the dentine beneath the enamel fare worse: in a study of 580 veneers followed for up to 12 years, those bonded to dentine were about 10 times as likely to fail⁴. This is one study and shows an association.
• Dark or stained edges. In the same meta-analysis, discolouration along the edges of ceramic veneers³ was reported in about 12.4 in 100. Composite (resin) veneers are less resistant to staining and wear than porcelain².
• A colour that no longer matches. The colour of a veneer cannot be changed once it is bonded⁵, and whitening does not change it. If your natural teeth darken or are whitened later, the veneers may stop matching them.
• The nerve of the tooth. A review of 37 studies of teeth that were alive before they received crowns or other indirect restorations found that in about 5 in every 100, the nerve lost its vitality⁶; in studies with more than ten years of follow-up, about 7 in 100. The certainty of this evidence is low. The more healthy teeth are crowned, the more teeth are exposed to this risk.
• Wear on the opposing teeth. Ceramic crowns can wear the natural teeth they bite against. In studies of monolithic zirconia lasting 6 to 24 months, the deepest points of wear measured on the opposing teeth averaged about 0.1 mm⁷. Surface roughness, polishing and your bite affect it.

Most veneer fractures and debonding happen in the first years¹. A restoration that is still in place may also have been repaired along the way.

What can be done

What a dentist can do depends on the problem, the tooth under the restoration and how much sound tissue is left. These are the usual routes, not a plan for your teeth. Before anything is re-bonded or remade, the dentist should look for the reason it failed, such as decay, gum disease, a poor edge or the bite, and deal with that as part of the plan.

• A small chip or crack. Small chips may be repaired; sometimes a new veneer is needed⁸. Composite is easier to repair than porcelain. Studies comparing repair with replacement of fillings found no clear difference in later failure, but the evidence was of very low certainty⁹ and did not study veneers. So there is no firm rule; ask why the dentist suggests one or the other.
• A veneer or crown that has come off. Keep it and see a dentist soon. A veneer that loosens may need to be re-bonded, repaired or replaced². Do not glue it back yourself: the tooth and the restoration need checking first.
• Stained edges or a colour mismatch. A restoration's colour cannot be whitened: whitening does not lighten crowns, veneers or fillings as it lightens natural teeth¹⁰. Whitening your natural teeth changes only them, so the restorations beside them can look darker afterwards. The options depend on what has changed. If your natural teeth have darkened, whitening them may bring them closer to the restorations. Otherwise the options include polishing a restoration, leaving a small mismatch as it is, or remaking it after talking through what that means for the tooth. If you plan to whiten your natural teeth, tell the dentist before anything is remade. Our tooth shade guide explains how a shade is chosen.
• Pain, or a nerve that has died. A tooth whose nerve has died needs root canal treatment to be kept; whether it can be kept depends on how much sound tooth is left. Pain can also come from decay at the edge of a restoration, the gum or your bite, so it needs an examination and usually an X-ray.
• Removing crowns or veneers. It is not possible to go back to the teeth as they were. A restoration that is taken off is replaced by another restoration, because the enamel removed does not grow back².

If several teeth are involved, ask for the plan tooth by tooth. Some restorations may be fine and need nothing, while others need attention. Our article on "Turkey teeth" explains what should come before a crown on a healthy tooth, and our article comparing crowns and veneers explains the difference.

A second opinion and your records

A second opinion is normal, and you can ask for one at any clinic. Before you go, collect your records. You can examine your file and take a copy¹¹, yourself or through a representative, and private dental clinics must record the diagnosis, treatment and X-rays tooth by tooth¹².

Ask the clinic that did the work for:

• your X-ray records, from before and after treatment
• the treatment plan, and a record of what was done to each tooth, including whether it received a crown or a veneer
• your copies of the consent forms
• the material and shade, if they were recorded

With these, the next dentist sees what was there before. They may still need new X-rays.

If you want to complain

Start by writing to the clinic that did the work. Beyond the clinic, the routes include SABİM 184¹³, the provincial health directorate, the local dental chamber and, for some disputes, consumer routes. Our article on choosing a dental clinic explains each one.

Time matters. Under the consumer protection law, claims for a defective service become time-barred two years after the service was performed¹⁴, even if the defect appears later, unless a law or the contract sets a longer period or the defect was concealed by gross fault or fraud. Whether your case counts as a consumer dispute is a legal question. If you think you have a claim, get legal advice early, and keep your records and photos.

Lowering the risk of further trouble

• If you clench or grind your teeth, tell your dentist. Grinding raises the risk of fracture. In a small retrospective study, among 30 patients with bruxism, those who wore a night guard had fewer fractures¹⁵. A guard may lower the risk; it does not remove it.
• Do not bite nails, pens or very hard food with your front teeth.
• Clean along the edges of every crown and veneer, where the restoration meets the tooth and the gum, and between the teeth.
• Keep regular check-ups, so that a small chip, a leaking edge or a gum problem is found while it is still small.

When to see a dentist

See a dentist, at the clinic that did the work or any other, if you notice:

• a crown or veneer that is loose, cracked or has come off (keep it, and do not glue it back yourself)
• pain when you bite, pain that wakes you at night, or sensitivity that does not settle
• gums that bleed, swell or recede around the restorations
• a restoration that catches your tongue or lip, or a bite that feels wrong

Swelling, pus or a bad taste near a restored tooth can mean an infection: see a dentist urgently, the same or the next day.

Emergencies. Difficulty breathing or swallowing, rapidly spreading swelling of the face or neck, a high fever or swelling around the eye are serious signs. Do not wait for a dental appointment: go to the nearest emergency department or call 112.

Frequently asked questions