Would Cutting Enamel To Remove Black Triangle Weaken my Teeth?

I am one week away to get my braces off. My teeth looks perfect, except that I have some black triangles formed between my teeth and gum. My orthodontist suggests to cut off part of the enamel to make my teeth narrower and less angled. Then he will close the space between teeth to make the black triangle disappear. My question is that would this procedure (trim some enamel) weaken my teeth and make them very sensitive? Would it be worth it, or would cause more problem in the future? Thanks!

Doctor Answers 7

Fixing black triangles

Black triangles can happen for a few reasons,1) triangular-shaped teeth, 2) loss of gum tissue between teeth due to gum disease, 3) roots of teeth tilted away from each other.

If the teeth are shaped like triangles, a very slight narrowing of the enamel near the ends, and then continued orthodontic treatment to fully close space between the teeth would work well.  

If there is a loss of gum tissue, it would first be important to try to find the reason for this and correct it, otherwise even after "fixing" the black triangle it could reappear. Gum tissue can be lost by too-vigorous cleaning especially with electric toothbrushes and flossers, or by bite problems especially if the front teeth touch the bottom teeth too hard when you close your teeth together.

If the roots of the teeth are tipped away, your orthodontist can try to get them more parallel, but sometimes this isn't possible due to your specific bite.

Good luck!

Black triangles can be reduced or eliminated by reducing contact areas between teeth

Your orthodontist has given you very solid advice about the reduction of black triangles.  A small amount reduction of enamal at the contact areas between teeth and the closure of the space created will have the effect of the reduction or elimination of the black triangle.  Don't worry.  The reduction of the enamel will not pose any  increased risk of decay.  A safe reduction would be no more than 1/4 the thickness of the enamel.


Kent Lauson, DDS, MS
Denver Orthodontist

IPR is quite common in black triangle reduction...

Assuming that you do not too much bone loss (ie periodontal disease), and that your teeth are not too fan shaped, an acceptable amount of enamel reduction between teeth to reshape their contact and make them broader (and then closing the remaining space) can dramatically change the appearance of a black triangle for patients orthodontically

Mazyar Moshiri, DMD, MS
Saint Louis Orthodontist

Use caution when slenderizing your teeth

This would work to eliminate the dark triangles. 

The concerns that I would have, and I am saying this not having seen you or your teeth,  are as follows. 

*  When you shave away enamel, you could cause tooth sensitivity if too much enamel is removed.  As long as you don't do more than about 1/2 mm you should be OK. 

*  The bigger concern I would have is that by narrowing the teeth, you will have to retract them to close the spaces.  This can take up tongue space, change your facial profile, and "lock" your bite in so that the lower jaw is somewhat trapped inside the upper jaw.  If there is a lot of retraction done, this can push the jaw back and impact the airway patency as well.

*  Locking the lower jaw in can lead to TMJ (jaw joint) problems as well.

Speak to your dentist and your orthodontist to see if they are concerned about any of these possible outcomes.

Martin Frankel, DDS
Toronto Dentist
3.7 out of 5 stars 3 reviews

Interproximal polish is minimal

While in your "minds eye" any removal of enamel is destructive, most interproximal contouring is extremely small and insignificant.  We sometimes add fluoride to help the polished area, but that may be overkill for most situations.  

Another option is Bioclear Method.  This is augmentive, and adds material where the space is, and extends onto the tooth for strength and esthetics.

Lance Timmerman, DMD, MAGD
Seattle Dentist
4.3 out of 5 stars 6 reviews

A simple solution to a common problem

Excellent question. It is actually one we dentists/orthodontists all asked ourselves. For years we have preached "protect enamel." We warn of wearing down teeth too much. Many bad things can occur if enamel isn't worn down properly; sensitivity, decay, crowns, root canals, etc.

There are a few truths to know that will put your mind at ease, when addressing a black triangle.

1) processed foods in our diet

2) cavemen

3) weak enamel

4) fluoride

Over the past century we have has a huge increase of process foods. The typical caveman diet (now in vogue again) was mainly of nuts berries and carcases. If you even have the opportunity to look at a caveman skull, notice their teeth. You will see not only are there more teeth than we have now, you'll see that they are very square and perfectly aligned.

The reason is our teeth we built to last with a caveman diet and be wore them down "interproximally". On average we actually have several mm of enamel surrounding the tooth, before any real harm is done. As orthodontists and dentists we can take advantage of this to achieve a much more cosmetic, often more hygienic and more stable result by preforming mild interproximal reduction (IPR). {Results are more cosmetic bc the black triangle are less noticeable or gone all together. Hygiene can improve bc food gets caught in the black triangles less and less surface area for plaque to accumulate. Stability is your long term orthodontic result is much more stable when their is a solid broad contact compared to a previous pin point contact.)

Some studies have actually stated that by doing IPR you are likely removing weakened (acid attacked) enamel and allowing for a more fortified enamel wall to protect the tooth. To insure that this is the case continue using a fluoride toothpaste. Anything with the ADA approve logo on it is acceptable, floss floss floss (they even have fluoride fortified floss) and a fluoride risen is never over kill.

Keep in mind black triangle will worsen over time because of osteoporosis so taking calcium is always a good thing too.

Word of advise: make sure you can visualize the tooth not looking too skinny prior to doing so, triangular teeth tend to be the best for IPR. Bonding can be another viable option for a black triangle if you'd like to add to the tooth and not take away from it.

Jacqueline Demko, DDS, MSD
Chesterfield Orthodontist

Interproximal reduction is often a good and easy solution to close black triangles.

A slight amount of enamel can be removed from the side of some front teeth in order to help close small "black triangles" .  This is a simple solution to a very common problem.  As long as proper care is taken, the teeth should not be sensitive or any more prone to decay. This includes only removing a small amount of enamel and re-polishing the surfaces afterwards. A few things to be aware of:

  1. It would be wise to treat the areas with a fluoride gel, rinse, or varnish afterwards.
  2. Your orthodontist needs to be sure there is sufficient overjet or clearance to bring the teeth inwards. And the small amount of inward movement should not adversely affect the lip profile.
  3. It might add a couple extra months to your treatment...but it should be worth it.

I have attached a short video to demonstrate how this works.  It is very worth the wait. 

Good luck,

Dr. Depew

Doug Depew, DMD
Atlanta Orthodontist
5.0 out of 5 stars 1 review

These answers are for educational purposes and should not be relied upon as a substitute for medical advice you may receive from your physician. If you have a medical emergency, please call 911. These answers do not constitute or initiate a patient/doctor relationship.