Tooth Sensitivity/Toothache

Why are my teeth sensitive? 
Tooth sensitivity is caused by the stimulation of nerve cells within tiny tubules located in the dentin (the layer of tissue found beneath the hard enamel that contains the inner pulp). When the hard enamel is worn down or gums have receded causing the tiny tubules to be exposed pain can be caused by eating or drinking food and beverages that are hot or cold; touching your teeth; or exposing them to cold air.

Hot and cold temperature changes cause your teeth to expand and contract. Over time, your teeth can develop microscopic cracks that allow these sensations to seep through to the nerves. Exposed areas of the tooth can cause pain and even affect or change your eating, drinking and breathing habits. Taking a spoonful of ice cream, for example, can be a painful experience for people with sensitive teeth.

Is tooth sensitivity a common condition?
Sensitive teeth is one of the most common complaints among dental patients. At least 45 million adults in the United States and 5 million Canadians suffer at some time from sensitive teeth.

How can I avoid sensitivity?
Some toothpastes contain abrasive ingredients that may be too harsh for people who have sensitive teeth. Ingredients found in some whitening toothpastes that lighten and/or remove certain stains from enamel, or sodium pyrophosphate, the key ingredient in tartar control toothpastes may increase tooth sensitivity.

To prevent sensitivity from occurring, use a soft bristled toothbrush. Avoid using hard bristled toothbrushes and brushing your teeth too hard, which can wear down the tooth's root surface and expose sensitive spots. The way to find out if you're brushing your teeth too hard is to take a good look at your toothbrush. If the bristles are pointing in multiple directions, you're brushing too hard.

How do I know when it's time to see a dentist? Is is more like a toothache?
If a tooth is highly sensitive for more than three or four days and reacts to hot and cold temperatures, it's best to get a diagnostic evaluation from Dr. McBride to determine the extent of the problem. Before taking the situation into your own hands, an accurate diagnosis of tooth sensitivity is essential for effective treatment to eliminate pain. Because pain symptoms can be similar, some people might think that a tooth is sensitive, when instead they actually have a fracture, cavity or abscess that's not yet visible.

How do I describe my symptoms to the dentist?
Sensitivity may be defined as a short sharp pain, which is usually initiated by hot or cold foods or exposure to cold air. Aching often follows. Because sensitivity may mean different things to a patient and dental professional, be sure to clarify exactly what you feel when you discuss the condition with Dr. McBride. Be sure to tell him when the pain started and if there is anything, such as the application of a warm compress, that helps eliminate the pain.

Do some products work to help decrease sensitivity?
Toothpastes for sensitive teeth usually contain a desensitizing agent that protects the exposed dentin by blocking the tubes in the teeth that are connected to nerves. In most cases, these products must be used on a regular basis for at least a month before any therapeutic benefits may be noticed.

What can the dentist do for my sensitive teeth? 
Dr. McBride and the hygienist have a variety of regimens to manage tooth hypersensitivity, including both in-office treatments and patient-applied products for home use. If you are diagnosed with dentin hypersensitivity, Dr. McBride may apply a desensitizing agent or a protective coating. We have a treatment of inorganic salts that can be painted on the exposed dentin (the sensitive part) which provides an insulation and desensitization of the nerve endings.  This desensitization is ideal for persons that find the sensitivity is noticeable when they attempt to drink cold beverages or touch their teeth. It can last between three months to over a year before reapplication.  

You may be prescribed a stannous fluoride gel or an over-the-counter desensitizing toothpaste containing fluoride and either potassium nitrate or strontium chloride. These ingredients help block transmission of sensation from the tooth to the nerve. It also might help to massage the special paste onto your gums with your finger after brushing. This must be reapplied daily to usually continue to keep the teeth from becoming sensitive again.

"Permanent" desensitization can be difficult to achieve.  A tooth can be filled if there is a hole or crevice in the tooth at the sensitive part, but can fall out if the cause of the hole or crevice was not treated.  Consult Dr. McBride whether or not this is an option for your situation.

What should I do after the dentist has applied a desensitizing agent? 
Listen closely to Dr. McBride's instructions. He may advise you not to eat or drink for a short period of time to eliminate all sources of irritation, such as acidic foods or medication, highly concentrated foods or flavored toothpastes. You may also be instructed to change oral hygiene habits that are likely to cause abrasion or use a daily fluoride application (a rinse or brush-on gel.)

What do I do if the sensitivity has occured since tooth whitening?
Ideally, we like to anticipate sensitive teeth before whitening and desensitize them.  If you did not previously have sensitive teeth, but find that you do after the application of the whitening system, this can be caused by dehydration of the enamel's microtubules.  Replenish with lots of unchilled water consumption and swishing with water; hold off on reapplication of the whitening systems by staggering the application to every other day and on the alternate days apply a fluoride gel in the trays, wearing this at bedtime as you would have the whitening gel.  This fluoride can be prescribed over the phone and picked up at a pharmacy, or purchased at our office.  Another way to manage sensitivity is to protect exposed dentin with something like petroleum jelly during whitening applications.  We have mini-sized cotton-tipped applicators for the application of the petroleum jelly, immediately prior to the application of the whitening system.   

Important note: Many times, sensitive teeth are due to a bite being off – the teeth are not hitting evenly - with more pressure on one or some teeth than there should be. Dentists who are aware of this and who are trained to evaluate systems, not just symptoms, will evaluate this possibility. If this is the case, treating with the above regimens may just be masking the symptoms of a deeper problem. Diagnosis is at least as important as treating.  This is one of Dr. McBride's specialties.

Sources: Dentalnotes, February 1998, January 1996, South African Dental Journal, August 1999, Vol.54 No. 8, Mark Ide; The Dental Advisor: "Dentin Hypersensitivity, " volume 12, number 2, June 1993, General Dentistry: "Hypersensitive dentinal pain attenuation with potassium nitrate, " January/February 1999; The Journal of the American Dental Association: "Assessing the efficacy of three dentifrices in the treatment of Dentinal Hypersensitivity, " Vol. 127, February 1996; George McLaughlin, DMD, Fellow of the Academy of General Dentistry.