The ABCs of Whitening Sensitivity

Have you ever had sensitivity when bleaching your teeth? Not fun is it? Whether you have or not, you already know you don't want your patients to go through unnecessary discomfort. The fact is, sensitivity is a reality of tooth whitening for some patients regardless of the bleaching products or the con- centrations used. Brushing up on the ABCs of bleaching sensitivity can help you better understand the A) symptoms, B) causes, and C) solutions, and can help you maximize your patients' whitening comfort.

Start by identifying the actual symptoms. Is this a case of soft tissue irritation or pulpal (dentin) sensitivity?

Soft Tissue Irritation
Concentrations higher than 15% can cause soft tissue irritation. The symptoms are tingling or stinging of the gums or the appearance of small blanchings or tenderness. There are three causes of soft tissue irritation. The first is an overlapping tray. Care should be taken to trim the tray away from the soft tissue. The second is overfilling the tray, which is a common mistake of many patients. Instruct the patient to decrease the amount of gel in the tray. Less is best! The proper dose is a small drop in each tooth indentation for a total of only .25cc (10-12 drops). Finally, soft tissue irritation is often caused by food, floss or toothbrush cuts and abrasions. Such wounds need to heal before whitening.

Pulpal Sensitivity
The symptoms, causes and solutions for pulpal/dentin sensitivity include:

Tooth dehydration - Symptoms may come in the form of a dull toothache or a headache. Using short-term modality (20 to 60 minute treatments) should avoid this problem. By the end of the first hour, the carbamide peroxide has been expended by approximately 70% 1. Wear beyond that point does less bleaching and continues to keep the teeth coated with gel. Short-term modality allows rapid saliva re-hydration to quickly counteract the hydrostatic imbalance created by the H2O2 in the dentin tubules and enzyme systems in the pulp. One answer for patient discom-fort is taking a break for a day or two and/or cutting back the treatment time.

Acute Sensitivity - When the patient has a history of acute pulpal sensitivity or is experiencing severe sensitivity, it is being caused by direct access to the dentin from recessed gums, enamel fractures, a chipped tooth, leaking margins, etc. The pain comes in the form of a jolt or shock from a single tooth. In these cases, a KNO3/Fluoride sensitivity toothpaste is recommended for use two weeks prior to whitening and then throughout the treatment. Toothpaste is the safest way to administer KNO3, and it allows the KNO3 to adequately neutralize the nerve endings and the fluoride to reduce dentin orifices. A common pain reliever such as aspirin or ibuprofen is also a good strategy for acute sensitivity due to exposed dentin.

Whether the sensitivity is from soft tissue irritation or pulpal sensitivity, have the patient take a break in the treatments for a day or two to allow him/her to normalize. Then make the appropriate diagnosis and adjustment and continue treatment. Those who experience discomfort will most likely not have the prior magnitude of discomfort.

Sensitivity is based on the patients' perception, which can be positively affected by you. Helping the patients categorize the sensations that are experienced during whitening treatments can help them put what they feel into proper perspective.

Remind them it is safe. Tell them that bleaching gels whiten much like cosme-tologists color or lighten the hair of millions of people. Cosmetologists use 10% to 40% hydrogen peroxide, while dentists whiten teeth with at-home strengths from 3.3% to 10.5% H2O2. Literally millions of people have had their teeth safely whitened - a magnitude of safety rarely enjoyed by other cosmetic procedures. Carbamide peroxide is prescribed to treat gums and combat gingivitis. Under professional supervision, whitening is safe and effective.

Inform your patients what to expect. Keep in mind that 15% to 20% of your patients will experience sensitivity wearing the tray alone. Another 15% on top of that will experience sensitivity with a placebo in the tray.2

Your awareness of these varied sensitivity ABCs will help your patients get the best results with the least amount of discomfort.

1. Clinical Research Associates Newsletter, Tooth bleaching, state-of-art '97, 21:4, 1:3
2. Haywood -- See Footnote 1, Pg. 3

Victoria DaCosta, RDH, is a practicing Dental Hygienist, innovator, and President of GumAerobics -- a fun & simple treatment for gum disease. Visit her website at www.gumaerobics.com, or E-Mail: victoria@gumaerobics.com. For more information, call 888/373-4000.