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Home » 10 Reasons You Have Tooth Decay Under Veneers

10 Reasons You Have Tooth Decay Under Veneers

Veneers protect teeth against damage, mask discoloration, and correct misshapen teeth. But, under certain circumstances, tooth decay under veneers is not impossible.

This article discusses extensively the most common 10 reasons that cause and accelerate the decay in the teeth underneath your veneers.

With reference to various cosmetic dentistry research journals, government agencies, academic organizations, and independent studies, we also analyze how you, as a dental patient, can avoid tooth decay under your veneers.

10 Reasons You Have Tooth Decay Under Your Veneers

Your dental veneers were not properly bonded

If your veneers are not properly bonded to your teeth, the result can be any or all of the following:

  • Veneers could chip or break off
  • There will remain a gap between the tooth surface and the veneers, which will act as a safe pocket for microorganisms like yeast or bacteria
  • Food particles may enter the space, causing discoloration and feeding the bacteria to accelerate tooth infection

According to Biomedical Investigations in Dentistry, two popular ways of preparing your tooth surface for veneers are:

  • Sandblasting or airborne particle abrasion
  • Silica coating

Sandblasting creates a rough tooth enamel surface to enable a micromechanical interlock between the teeth and the bonding material. Silica coating means blasting the tooth surface with silica-coated alumina particles.

Both of these processes require a superior level of skills and experience. The absence of that may result in improper installation of your veneers and tooth decay.

Fractured or broken veneers are causing tooth decay

Your new veneers can break or fracture for several reasons. The following stand out:

  • Constant grinding or clenching of your teeth (You are not a good candidate for dental veneers if you clench or grind your teeth – The Journal of the American Dental Association)
  • Improper design or installation of the veneers
  • Eating hard, crunchy, or sticky foods
  • Weak tooth structure due to root canal treatment or dental decay
  • Aggressive enamel removal as part of your cosmetic treatment

The fracture can happen only at the veneer level or at the veneer and cement level.

Some fractures may be repaired. Consult your dentist to learn if yours can be saved. If not, they have to be removed and replaced with new ones.

The decay began in the unprotected part of the tooth

Veneers do not cover the backside of your teeth or what remains of them below the gumline. A large part of your real teeth remains open to your oral environment.

If you do not take proper care of your teeth, they may suffer from decay.

The decay may begin as simple gum disease or plaque buildup, gradually becoming cavities or tartar formation.

Under normal circumstances, you need to have your teeth in good condition to make your veneer treatment successful. The best way to do that is to talk to your dentist about your dental problems.

Poor dental hygiene may not sound important, but it may cost you a fortune.

The oral bacteria were not extracted properly before installing your veneers

Before installing the veneers for you, your dental professional must extract all bacteria from the surface at the front of your teeth. If due diligence is not done, the bacteria may infect the bonded tooth surface, thus causing serious tooth decay and complications.

Entrapped bacteria may cause bad breath in your mouth.

They may gradually overtake the edges of your veneers and spread to your gums. The result can include the following:

  • Tooth decay under veneers
  • Gum inflammation
  • Bleeding
  • Receding gums

Poorly fitted dental veneers are behind your tooth decay

Veneers cover the front part of the tooth to give you a beautiful smile. They are a great way to cover minor imperfections on your tooth’s surface.

However, for them to be effective, veneers should fit snugly against your teeth. If they fit poorly, they will allow microorganisms and food debris to enter beneath them and cause cavities.

In addition, your teeth may suffer decay if your veneers do not cover the entire prepared tooth surface.

Practicing good oral health with a solid oral hygiene routine may not be enough to protect your teeth in such circumstances.

Consult your dental practitioner immediately if you believe your veneers are not a perfect fit for your teeth. Your dentist will examine your veneers and gums and solve your problem.

Delaying your treatment is not an option. Any delay may compromise your oral health.

Your root canal treatment has failed

If you had undergone root canal treatment on one of the teeth receiving a veneer, you need to pay special attention to it. Like any other cosmetic dental restorations, root canals may fail. When they do, they let bacteria into the pulp chamber through to the apex of the tooth. The result is an acute infection and tooth decay.

Root canals may fail for many reasons, including the following:

  • The load of bacteria is too high to control
  • Leaks in the composite filling material
  • Absence of good oral hygiene
  • Severe gum disease
  • The sealing materials have broken down
  • Fracture

In this case, your veneers have nothing to do with the decay in your teeth. Other dental conditions, for example, root canal failure, are causing the decay.

Chronic gum disease may be active behind the tooth decay under your veneers

Sometimes it is difficult to determine whether gum disease is causing tooth decay under veneers or veneers are causing gum disease that causes tooth decay.

We have spoken about ill-fitting veneers above. We know that they can cause gum inflammation and gum disease.

Sometimes gum disease begins with the process of installing veneers. If the process is too aggressive, your gums may pull away from your teeth, creating a haven for bacteria to grow. That bacteria may travel around the veneers looking to attack your teeth – given that you maintain poor oral hygiene.

Excess bonding cement remaining on your teeth

Your gums may be inflamed if your dentist does not remove the excess bonding cement from the surface of your teeth.

The cement may irritate your gums and cause inflammation and bleeding.

The condition may soon turn into gum infection or gum disease. It may be difficult to clean your infected gums, which may help the infection reach under the veneers.

The gums can be irritated and inflamed because of allergic reactions to dental ceramics. The result is the same: gum infection and tooth decay.

The margin of the veneers is too far from or below your gum line

It is of utmost importance that your reputable cosmetic dentist places your veneers exactly at your gum line.

Any veneers far away from the gum line are sure to irritate your gums. On the other hand, if they are placed below the gum line, that will affect your oral health.

Bacteria will leak into that space and cause infection and tooth decay.

Dental trauma has everything to do with tooth decay under veneers

If you are into physical sports and do not wear mouthguards to protect your teeth, you may experience trauma in your mouth.

Such a trauma or impact may damage your veneer teeth internally. Your teeth may chip or fracture. The condition may turn into bleeding, infection, and/or tooth decay.

Tooth decay under veneers: A note from SupreDent

Veneers cannot protect or regenerate a failing tooth. If a tooth is decayed, the first step should be to seek treatment for that decay. Even an experienced cosmetic dentist cannot protect a failing tooth without proper treatment. What they can tell you, however, is that you treat the failing tooth first before enhancing its esthetic look with veneers.


Can veneers Infect your teeth?

Veneers do not infect your teeth. However, if you have ill-fitting veneers, or veneers that are fractured, there is a chance that your teeth will be infected. The infection is caused by the fracture through which bacteria penetrate under the veneers to attack your teeth.

What is prepping?

Prepping is preparing your teeth for veneer treatment. Your dentist will remove a thin layer of enamel off your teeth to make room for thin veneer shells. In other words, your dentist will reshape your teeth to make them ideal for your veneers.

I have gum disease. Can I get veneers?

You can get veneers, but your gum disease has to be treated first. Consult your dentist to make a custom treatment plan for you. Veneers cannot save failing teeth. Veneers on failing teeth will fail.

What is the best veneer for me?

There is no best or ideal veneer in the market. The best veneers for you are the veneers that suit your teeth best. You have to consider several factors before committing to getting veneers treatment. They are: the esthetic outcome of the treatment, treatment cost, condition of your teeth, the color or shape of the veneers, the material you choose for your veneers, etc.

What is the survival rate of veneers?

According to research, conventional veneers survive at least 9.32 years while no-prep/minimally invasive veneers survive 10.28 years without failure.


Martin Ågren, Wen Kou & Margareta Molin Thorén (2019) Bond strength of surface-treated novel high translucent zirconia to enamel. Biomaterial Investigations in Dentistry, 6:1, 35-42.

Nalbandian, S., Millar, B. The effect of veneers on cosmetic improvement. Br Dent J 207, E3 (2009).

Smielak, B., Armata, O. & Bojar, W. A prospective comparative analysis of the survival rates of conventional vs no-prep/minimally invasive veneers over a mean period of 9 years. Clin Oral Invest 26, 3049–3059 (2022). 

Also from SupreDent:

Dental Porcelain Veneers: Costs, Procedure, and Benefits

Tooth Abscess: Causes, Treatments, and Prevention