You wouldn't expect there to be any objections when you begin to whiten your teeth. But objections can come from unexpected sources. The fact that the process triggers pain in a tooth (or teeth) means that your teeth themselves object to being whitened. Alternatively (or even additionally), you might notice immediate discomfort on your gums. But is a little pain in a tooth or your gums a normal part of the process?
A Mild Reaction
The whitening process shouldn't hurt. A small amount of the teeth whitening gel will make contact with your gums, and this should trigger a mild reaction—which should be a light tingling (at most). Your teeth themselves may become temporarily sensitive while in contact with the whitening gel, but this should fade shortly after you remove the applicator trays containing the whitening gel from your mouth. And remember, this should only be mild sensitivity, and not pain or discomfort. This adverse reaction can indicate a few possible problems, depending on whether it's experienced in a tooth or across your gums.
Discomfort in a Tooth
A sore tooth while whitening can suggest a breach in the tooth. This may be an untreated cavity, a small crack, or general erosion of your dental enamel. It may not necessarily be visible either. Essentially, the whitening gel's active ingredient (carbamide peroxide or hydrogen peroxide) has made contact with the dentin of your tooth. This dentin should be safely hidden beneath your dental enamel, but any enamel deficiency can expose your dentin. Dentin contains multiple microscopic canals which lead to the pulp chamber at the tooth's center, where the tooth's nerve is located. The whitening gel is irritating this nerve, causing your discomfort. The deficiency in your enamel must be corrected, so you may need to have a cavity filled or have problematic enamel augmented with composite dental resin. But what about when it's your gums that are hurting?
Discomfort in Your Gums
Sore gums during whitening is often a type of chemical burn. Excess whitening gel is escaping from the applicator trays and is making prolonged contact with your gums. A small amount of escaped gel will provoke a light tingling. An excessive amount will cause discomfort. This is a problem with teeth whitening gel kits—the one-size-fits-all applicator trays don't tend to offer the most appropriate fit. Unless the tray tightly hugs your teeth, the gel can easily be applied inconsistently, oozing out in significant amounts. So what should you do when your gums are experiencing pain due to your whitening treatment?
How a Dentist Can Help
To whiten your teeth at home, you should see your dentist first. Professional cleaning will be advantageous to remove surface stains (making it easier to whiten your teeth). You should in fact have your dentist make you a customized applicator tray designed for the contours of your teeth. This permits even coverage of the teeth whitening gel, without any escaping and harming your gums. You'll actually get the best results by having your dentist perform the initial treatment, meaning your at-home efforts then only need to maintain these results.
It shouldn't hurt to whiten your teeth, so pain or discomfort is a sign that something is wrong. Be sure to have the cause investigated and addressed before continuing your whitening efforts; otherwise you risk endangering your teeth and gums.