Do all teeth whiten?

Have you recently stared longingly into a mirror and wondered where it all went wrong for your teeth? You may have noticed your teeth getting progressively yellower as the years have gone by and can’t help but think maybe you have been subconsciously subjecting your teeth to some form of torture. Teeth can stain or discolor for a number of reasons and sometimes there do not have to be dramatic conditions for them to occur. Nevertheless, you can always whiten your teeth through a session at your dentist’s if your teeth start to wither into an unnatural yellow tint. Or can you? Did you know that there are some situations when teeth whitening may not give you the results you need?

Types of staining

Tooth discoloration can occur as a result of surface stains, or due to actual changes in your tooth substance, sometimes even due to the combination of both factors. Dental professionals have isolated three main categories of tooth discoloration, says the American Academy of Cosmetic Dentistry.

Extrinsic stains: These build up on the surfaces of the teeth usually occurring due to pigmented residue from foods and beverages. A common form of extrinsic tooth stains occurs as a result of excessive tobacco consumption. This form of tooth discoloration responds well to teeth whitening procedures.

Intrinsic stains: Also known as internal or deep stains, these kinds of stains can occur from below the surface of the tooth. A common culprit for intrinsic teeth staining is excessive fluoride use. A professional or at-home chemical teeth whitening procedure may be required to get rid of these pesky stains.

Age-related stains: A combination of intrinsic and extrinsic stains, these cause the naturally yellowish dentin to show through due to the wear of the overlying enamel.

What causes teeth staining?

There are multiple contributing factors responsible for the discoloration of the teeth, some of which could be within limits of prevention.

Foods and beverages: Readily pigmented foods such as coffee, tea, red wine, and edibles like berries may cause your teeth to stain.

Tobacco: Cigarettes and smokeless (chewing) tobacco can both greatly impact the color and structure of your teeth

Oral care: Poor oral hygiene may cause tartar and plaque to accumulate on your teeth surfaces, furthering tooth discoloration.

Trauma/disease: Trauma, illness, or disease may sometimes affect the development of enamel in children and can cause discolored teeth. In adults, trauma to the teeth due to accidents can also discolor teeth.

Medications: Certain medications such as those for high blood pressure, chemotherapy, antihistamines, and antipsychotics can also cause teeth to stain.

How does teeth whitening work?

Teeth contain organic molecules in their enamel and dentin that reflect light and are responsible for their coloration. The more complex these molecules are, the more light they reflect, and the more teeth appear stained or discolored. Carbamide peroxide, upon activation, breaks down into hydrogen peroxide and urea.

Hydrogen peroxide is the active whitening agent used to whiten teeth and is used in most in-office teeth whitening procedures. Because this compound is a weak acid with strong oxidizing properties, it can easily pass through the barriers of the tooth and break down complex molecules. As complex molecules begin to reduce in number, less light is reflected and the enamel and dentin appear less stained and more appealing.

Do all teeth whiten?

If you are an advent smoker or drinker, you may be content knowing that you can always turn to teeth whitening as a means to brighten your dulling smile. However, that may not always be available to you. The American Dental Association informs that not all teeth can whiten and thus it is of primal importance that you talk to your dentist before deciding to whiten your teeth.

Some of the situations when your teeth may not respond to teeth whitening as expected are:

Degree of staining: The ADA maintains that teeth whiteners may not correct all types of discoloration. For example, yellow teeth will probably respond well to teeth whitening, brown teeth may not bleach as well, and teeth with gray tones may not bleach at all.

Artificial teeth: When artificial caps are installed, they are created to match the color of your surrounding teeth. Whitening will not work on caps, veneers, crowns, or dental fillings as the porcelain or ceramic used does not retain bleaching and will never stain nor whiten.

Tooth injury: Another classic example of teeth whitening backfires is one caused by tooth injury. Teeth whitening will not work on teeth that have been subjected to a sustainable degree of trauma or injury.

Medication-related staining: Discolorations such as those from medications cannot be changed by teeth whitening. For example, if you took tetracycline as a child, you may have antibiotic staining of the teeth. These intrinsic stains are resistant to teeth whitening so you may well be prepared!

Tooth wear: Teeth wear and tear caused due to age or habitual grinding can cause the underlying dentin to show through. Bleaching products will not help in this situation because they do not affect the dentin.

Furthermore, all teeth may not reach the same level of whiteness. Each tooth has its maximum capacity for whiteness and although bleaching can lighten your teeth even exceeding your natural color, regardless of your stains, your natural color cannot be altered beyond a certain point. Teeth whitening can help in certain situations but may be futile in many others, so it is important that you connect with your dentist about the effects before trying on a procedure! Stay safe and shine bright!

References:

American Dental Association: https://www.mouthhealthy.org/en/az-topics/w/whitening

NHS: https://www.nhs.uk/live-well/healthy-body/teeth-whitening/