Wary of Whiter Teeth? Considering Safety and Sensitivity
by Hyo Lim
People visiting the dentist frequently want to know, “How can I get my teeth whiter?” Driven by the entertainment industry’s obsession for beauty and youth, Americans are striving for whiter, brighter smiles.
There are a variety of options for achieving whiter teeth. Let’s start by answering these questions: What actually is bleaching? Is bleaching safe? What products are effective, and what products and methods are more natural?
Tooth bleaching is a process that oxidizes or breaks apart staining compounds that have discolored or darkened teeth. Teeth are composed of a hard but porous outer layer called enamel and a softer, porous inner layer called dentin. The dentin encases the pulp, the innermost component of the teeth that contains the nerves and blood vessels. Extensions of the nerves infiltrate the dentin and make this portion of the tooth alive. Enamel, unlike dentin, has no innervation. Compounds from food, drinks and smoking enter the enamel over time and eventually reach the dentin. It is this process that slowly discolors teeth.
The bleaching agent or chemical used in whitening is usually hydrogen peroxide or its derivative. Lower concentration hydrogen peroxide is incorporated into over-the-counter products like Crest White Strips. The over-the-counter products, although much cheaper, produce unpredictable results because the concentration of the bleach is low. Also, people would be wise to have an exam and consult with their dentist before using over-the-counter kits—if there is an undetected cavity or if bleach gets into the the nerves of the tooth through a crack or a filling, there can be pain and complications that will require more extensive dental work to repair the damage.
There are two separate bleaching processes performed by dentists: take-home and in-office. In both processes, the concentration of hydrogen peroxide used is much higher than that found over the counter. Take-home bleaching trays are fabricated from molds taken of the patient’s teeth. The patient places bleaching agent in the trays and either wears them for a short time or sleeps in them, depending on the concentration of the hydrogen peroxide. Take-home trays combine the effectiveness of the in-office bleaching with the flexibility of controlling the bleaching process.
The other process is an in-office application of a strong bleaching agent, coupled with a high-intensity light to accelerate the whitening. With higher strength comes a greater risk of sensitivity and discomfort. Improper use or technique can inflame the nerve and irritate the gums. Sharp pains or “zinging”, as well as sensitivity to temperature and spontaneous toothache, are not uncommon. However, concerns of possible oral cancer risk have not been supported. If bleaching is done in moderation and under the supervision of a dentist, it is a safe process.
For those that prefer a natural route, a method for preventing staining is to brush after ingesting food or drink that can discolor, like coffee, wine and tea. Making more frequent visits to the hygienist can help, as can using a simple, safe, at-home toothpaste made by combining baking soda and over-the counter hydrogen peroxide antiseptic.
Dr. Hyo Lim, DMD, practices at Dental Wellness Centre, in King of Prussia. Connect with him at 610-265-4485 or DentalWellnessCentre.com.