Sensitivity: Exploring the Root Cause of the Dental Patient’s Pain

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Tooth sensitivity is one of the primary factors prompting patients to visit the dental office.

Tooth sensitivity is one of the primary factors prompting patients to avoid the dental office.

Both statements above are true.

Let’s take the first statement and extrapolate. A scheduled patient hasn’t been in the office for a while, is slightly overdue, or perhaps is a new patient. The fact that their sensitivity (which, to some, is felt as pain) has prompted them to visit the dental office shows that the tooth sensitivity is of great concern to the patient.

Even if they are treated on a routine basis, the fact that they have set an appointment to have their sensitivity examined is a big deal!

Now the second statement may trigger some red flags since the patient more than likely has had tooth sensitivity/pain for a long time, and the “severity” has reached a point of requiring your attention. This patient needs a warm welcome, understanding, and comforting care. He/she is most likely terrified of the dentist from either previous “bad” dental experiences or simply fear of the unknown.

Treat with respect, sincerity, and listen to their story. Motivational questions and understanding their needs help the patient feel confident and respectful of the dental appointment. After all, it is an honor that they chose your office to treat their dental issue.

In both cases, he/she is properly welcomed, and, upon review of why they are visiting today, it is discovered that “tooth pain” prompted them to pick up the phone and schedule an appointment. Your job is to get the facts and be a tooth sleuth of sorts, gathering data for the doctor.

This data-gathering includes questions, radiographs, intraoral images, and visual examination for starts. How long has the patient been in pain? What causes the pain? Hot, cold, pain with pressure, or throbbing for no particular reason?

Since radiographs are basically two dimensional, they may or may not show the cause of the pain. Intraoral images are an amazing adjunct to dental diagnostics as they allow enlarged visual examination of tooth structure. Intraoral images may help the patient see their toothbrush abrasion or attrition, exposed root surfaces, craze lines, fractures, or cracks, as well as white lesion decalcifications, failed restorations, and open margins.

Dentinal hypersensitivity is a common condition of transient tooth pain which is usually the result of gingival recession and exogenous stimuli. Exposed root surfaces that have been abraded by a toothbrush subsequently expose dentinal tubules as a result of the loss of cementum on root surfaces.

Periodontal disease and bruxism are also considerations for the resulting gingival recession. Treating dentinal sensitivity is of concern. However, the causative factor must also be addressed. Hence, a comprehensive periodontal evaluation or bruxism examination needs to be performed as a standard of care.

Causes of Exposed Dentinal Tubules

Reasons for continued dentinal tubular exposure

  1. Poor plaque control, i.e., acidic bacterial byproducts
  2. Excess oral acids, i.e., sodas, fruit juice, swimming pool chlorine, bulimia
  3. Cervical decay
  4. Toothbrush abrasion
  5. Tartar control toothpaste1

Exogenous stimuli: The exogenous stimuli include thermal (cold), tactile (touch), or osmotic changes (sweets or drying the surface)2 or acids.

Why Do Root Exposures Cause Pain?

This is a common question many patients ask regarding tooth sensitivity and pain. Remember, to some, it is felt as pain. Yes, dentin is an insulator, but temperature changes may still cause tooth pain even though the pulp seems protected. The Braanstrom’s hydrodynamic theory of dentin hypersensitivity explains it well:

Fluids within the dentinal tubules are affected by exogenous stimuli. These fluid movements stimulate a nerve receptor sensitive to pressure (baroreceptor) which causes depolarization (nerve endings fire off).1

The brain receives this information as an instant sharp pain. Ouch! Basically, fluids affected by temperature changes move in and out of the dentinal tubules and stimulate receptors which trigger pain to the brain. This last sentence is an easy way to describe to your patients why their root exposures are causing them temperature sensitivities and/or pain.

Now What?

Ruling out failed restorations, fractures, cracks, or bruxism, the most conservative approach is to protect the exposed root surfaces from further damage. This starts with thorough home-care instruction on how to keep the cementum/dentin plaque-free without causing more erosion.

Education is key. With the patient’s permission, demonstrate proper sulcular brushing with an extra soft toothbrush. Using a hand mirror, show and explain that the toothbrush needs to gently navigate the gumline vs. scouring the teeth. Take images of their root exposures prior and post-brushing for cause and effect.

Nutritional counseling is as important as oral hygiene instruction in controlling the continuation of dentinal sensitivity. All day snacking and drinking not only produce caries but chronic dentinal sensitivities from ongoing acid attacks.

Treatment Options

  1. Occlude dentinal tubules to prevent fluid flow: stannous fluoride or a combination of stannous and sodium fluoride, (dentinal sealers), fluoride varnishes
  2. Desensitize the nerve: potassium nitrate toothpaste (suggest take-home fluoride trays)
  3. Full root coverage: grafting, pinhole technique coverage, or simple bonding
  4. Endodontic treatment and crown: worst-case scenario

Using a dentin desensitizer followed by fluoride varnish seems to work quite well and is a quick and easy in-office procedure for patient and practitioner. This will most likely need to be repeated at each dental appointment for effectiveness since exogenous stimuli will still occur. Recommend a sensitive OTC toothpaste as well as a prescription strength sensitivity toothpaste for continued comfort.

Remember, every patient has varying results when treating sensitive teeth. Inform the patient that occasionally the only way to desensitize a tooth is to devitalize it with a root canal, but that is “worst-case scenario.”

The patient will be the informer. He/she will surely let you know if chosen treatment has diminished sensitivity to a manageable level. There are so many desensitizing products to choose from that it can be overwhelming. To help make an informed decision before purchasing a large volume of products, ask your dental product representative for differing samples to try. Take note of the results.

Before you leave, check out the Today’s RDH self-study CE courses. All courses are peer-reviewed and non-sponsored to focus solely on pure education. Click here now.

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  1. Jacobsen, P., Bruce, G. (2001) Clinical dentin hypersensitivity: understanding the causes and prescribing a treatment. The Journal of Contemporary Dental Practice. Feb. 15, 2001, 2(1):1-12. Retrieved from
  2. Addy, M., Mostafa, P., Newcombe, R. (1990) Effect of plaque of five toothpastes used in the treatment of dentin hypersensitivity. Clin Prev Dent. 1990;12; 28-33.
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Rebecca Marie Friend, BS, RDH
Rebecca Marie Friend, RDH, BS, attained her Associate of Applied Science degree in Dental Hygiene from Ferris State University, Big Rapids, Michigan, in 1987, where she also met and married her husband. She has been a practicing dental hygienist for over 30 years and has raised three sons while working as a full-time clinical dental hygienist. Rebecca currently practices in Battle Creek, Michigan. She resides in neighboring historic Marshall, Michigan. Rebecca is board certified in Nitrous Oxide and Local Anesthesia Administration and is certified in low-level laser therapy. Continuously striving to improve upon her skills and methods of forward-thinking in the dental world, she recently attained her Bachelor of Science degree in Oral Health Promotion through Action Research at O’Hehir University. She is actively involved in a mentorship with students at O’Hehir University. “I take pride in my abilities as a skilled periodontal therapist. I enjoy the patient-practitioner relationship that develops when trust and health are gained, taking mindful care of every individual that I connect with. The benefits of helping others achieve a healthy mouth and regain their confidence with a great smile and healthier self are very rewarding. Whole-body health begins with the mouth.” In her free time, Rebecca enjoys visiting the beautiful shores of Lake Michigan, where the sunsets are magical, the dunes are stunning, and the rocks are a collector’s delight. She loves to immerse herself in nature whenever she gets a chance and enjoys canoeing, kayaking, nature walks, flexibility training, yoga, and little “get-a-ways” with her husband. Family life has always been important to her, and now that her three grown sons have spread their wings, she has a little more time to spread hers.