The concept of dental bleaching has been around for over 50 years with people trying all types of home remedies to brighten their smile. Recent advances in technology have led to many different products that will help achieve whiter teeth. The medicines used for whitening are primarily carbamide peroxide and hydrogen peroxide that are mixed with various gels or liquids or toothpastes to help bubble away extrinsic stain.

The type of stain will determine the success of bleaching. Colors of teeth that are gray or brown will be harder to whiten than yellow teeth.  The color of the tooth represents the reason for the stain. If the teeth are gray or dark or have bands, they may be tetracycline stains due to a mother ingesting antibiotics while a baby’s enamel was forming. Other drugs have also been found to create changes in the color and formation of the enamel coverings of teeth.

Professional teeth whitening can be performed in several ways. First of all, it is important to see your dentist for a thorough exam and x-ray evaluation to make sure that the teeth are healthy and there are no cavities that could become irritated by the dental bleaching solutions. Especially for patients seeking services to be performed by a technician that is not a dentist, a checkup and examination is imperative to rule out any pathology.

Here are some of your most common professional teeth whitening questions answered.

What types of whitening are there?

  1. Mouthguard whitening: This is when custom trays are fabricated that will seal the whitening solution on the front surfaces of the teeth for a directed period of time. Usually this will take 3-4 weeks of daily wear to achieve a multiple-shade improvement.
  2. In-office whitening: These treatments usually involve painting a liquid barrier on to the patient’s gums to prevent burning or irritation from the dental bleaching solution. Then a light or laser is moved close to the teeth to accelerate the whitening process. Multiple shades of improvement are usually achieved in an hour-and-a-half visit.
  3. Super-deep whitening: This is a combination of one or two in-office bleaching sessions with mouthguard whitening occurring in between the office visits. The theory behind this more labor-and-cost-intensive treatment is that the slow and gradual removal of stain can allow the whitening process to proceed deeper within the pores of the tooth, achieving whiter teeth with the best color possible.

How does dental bleaching work?

The enamel crystals in a tooth are the hardest substance in the body. There are very hard enamel rods and below the enamel are tubules or pores that reach to the nerve of a tooth. When acidic solutions are in contact with the enamel matrix, pores are opened and the oxidizing properties of the hydrogen or carbamide peroxide will oxidize any organic debris in the tubules of the tooth. This allows the stain to be dissolved and cleaned the way peroxide works on countertops to remove debris and stain.

Do lasers work better than the lights for achieving whiter teeth?

While there are a few studies that have attempted to show that lights or lasers improve the speed or quality of whitening, literature reviews have shown that they are of minimal value to the professional teeth whitening process. They certainly look impressive but the heat of the lights or lasers may act to dehydrate the tooth and give them the illusion of being lighter at the end of treatment. People need to realize that as the water re-enters the tooth, they may get a bit darker due to pull back after the in-office whitening procedure. There are dentists that feel the lights do improve the bleaching process so it is inevitably up to their philosophy of care.

There are mouth rinses and toothpastes that claim to whiten teeth, do these work?

Any product that is put in the mouth for a very short time will not have the whitening ingredients in contact with the enamel long enough to create deep changes. That being said, the use of these rinses and toothpastes may work after a professional teeth whitening session to help stain from re-accumulating on the teeth.

Does mouthguard whitening work as well as the whitening with a light?

Yes! The use of tray whitening will take longer but will produce the same results over time that you would achieve with an in-office session. This assumes that you will consistently and regularly use the trays as directed and not skip sessions.

My dentist made me trays even with the in-office whitening. Is this because the office whitening wasn’t effective?

No, the trays that are often made are to be used to continue the whitening process so that at the end of the in-office session, you may go even whiter than what was achieved at this visit. As well, in some offices, you may continue to purchase refills at a decreased cost as long as you are a current patient of record. That encourages people to allow the dentist to monitor your overall dental health.  You may wish to touch up the whitening once or twice a year depending upon the types of food you eat and the rate at which your teeth pick up stains.

Will my teeth hurt after dental bleaching?

They may hurt or be sensitive after whitening. Some offices start their patients on a fluoride or fluoride-containing gel prior to the whitening appointment to help decrease sensitivity. The whitening process can result in sensitive teeth, “zingers,” which feel like little jolts of electricity when you suck in air or slight aches in the teeth. It is important to discuss this with your dentist prior to your whitening session. The sensitivity will usually subside completely a day or two after the whitening has been discontinued. Mild analgesics like Tylenol or Advil may help with postoperative discomfort.

I had my teeth whitened and had white blotches appear on my teeth. What are these?

As teeth are dehydrated during whitening, there are different enamel colorations that may appear that are present in deeper enamel layers. These are called hypocalcifications, and they are normal. The hydrating of your teeth with saliva later will mask these spots. Over time the whitening process will deepen and these colors will help achieve a whiter look to your teeth.

I have bad tetracycline-stained teeth and was told by my dentist that whitening won’t work. Will deep bleaching help?

While there are never any guarantees in dentistry, there are studies that have shown that severe tetracycline stains can be greatly reduced and possibly eliminated with prolonged bleaching over a several-month period. Many people have tried whitening for a week or two and become discouraged. It may be possible to achieve great improvements, but it can take 3-6 months of consistent effort.

I had one dark tooth and the doctor said we could bleach it. Is this the same type of procedure?

When a tooth dies (non-vital), the blood vessel may explode into the tooth, causing blood to get into the pores of the dentin. In these instances there are procedures for internal whitening that will help eliminate the stain from inside the tooth.

How is this non-vital bleaching performed?

When a tooth dies it requires a root canal to remove the residual dead nerve and blood vessels. Once this is completed, the root canal system is sealed with a glass ionomer cement or filling, and the pulp chamber (main nerve chamber in the tooth) can be filled with bleaching solution for a period of weeks to remove the stain. This bleaching material is placed and the hole is filled with a temporary filling. The bleaching solution is refreshed weekly until the color of the adjacent tooth is matched. It is usually advisable to “over-bleach” to accommodate any pull back in color that will occur post whitening. Once the desired color is achieved, the tooth will be flushed and clean for two weeks prior to putting in a final filling. That is because the bleaching solution can weaken the bond of your filling so all bleaching solution should be out of the tooth so the oxygen can dissipate and not interfere with the bonding that is to be done.

If I want to do this non-vital whitening but also want to whiten the other teeth, can it be done at the same time?

Yes, the hole in the tooth can be left open (it is sealed) and a mouthguard tray can introduce bleaching solution to the external surfaces of the teeth. Some can be injected directly into the tooth-then the tray is worn to hold it all in place. When not being bleached, wax can be put in the hole to prevent food from getting into the tooth.