Toothpaste ingredients can lead to lesions

May 1, 1997
Almost any toothpaste can cause contact stomatitis, also known as dentifrice stomatitis, when used by a susceptible patient. Symptoms generally are painful and include a burning sensation, tissue irritation, vesicle formation, and tissue sloughing.

The simple remedy? Don`t use it for a week

Trisha E. O`Hehir, RDH

Almost any toothpaste can cause contact stomatitis, also known as dentifrice stomatitis, when used by a susceptible patient. Symptoms generally are painful and include a burning sensation, tissue irritation, vesicle formation, and tissue sloughing.

When searching for the cause of oral irritations, we may look for a more complex etiology when, in fact, toothpaste may be the cause. Toothpaste ingredients linked to oral irritations include sodium lauryl sulphate, pyrophosphate, and flavoring agents. Simply asking the patient to forgo toothpaste use for a week may solve the mystery.

Some oral irritants linked to toothpastes

Sodium lauryl sulphate (SLS) is a synthetic detergent widely used in toothpastes and also is found in shampoos, cosmetics and laundry detergents. It also is a standard detergent used to test skin irritation. SLS affects the barrier function of skin by enhancing permeability. Dental researchers have now linked SLS to increased gingival blood flow as well as mucosal irritations.

Researchers in Norway used upper and lower splints fabricated with fiber optic laser Doppler probes imbedded just above the gingival margin between the central and lateral incisors.

To establish baseline data, the 14 test subjects reclined comfortably with the splints in place for 10 to 15 minutes. The splints were removed and the anterior mucosa on one side of the mouth received a cotton swab application of SLS while half the control sites received an application of water and the other half received nothing. After 90 seconds, the splints were replaced and the blood flow again measured.

The control sites demonstrated an initial drop in blood flow, probably due to the splint being at room temperature. After an initial drop, the control sites returned to baseline. The sites treated with SLS showed an immediate increase in blood flow, which continued to rise for eight minutes. After that time, blood flow returned toward baseline. The average increase was 120 percent of baseline. Ten of the 14 participants reported a burning sensation that coincided with the increased blood flow.

Testing the detergent on women

To test for mucosal irritation, researchers used SLS on pre- and post-menopausal women. Instead of brushing with toothpaste, the study subjects put a small amount of toothpaste into a maxillary splint which they wore for two minutes twice a day for four days.

This splint testing was repeated four times with toothpastes of varying sodium lauryl sulphate concentrations. In between the four-day splint tests, they brushed with a detergent-free toothpaste for 10 days. This gave the oral mucosa a chance to recover from each test toothpaste. Each group consisted of 14 women, with smokers comprising half of each group.

All the pre-menopausal women developed desquamative lesions, while only half the post-menopausal women showed evidence of mucosal irritation. As the concentration of SLS increased, the difference between the groups also increased, with considerably higher scores in the pre-menopausal group. No one experienced lesions with the detergent-free toothpaste.

An interesting link was noted between smoking and the risk of mucosal irritations. No influence was noted in the pre-menopausal group, but smoking seemed to reduce the risk for desquamation in post-menopausal women, perhaps due to more years of smoking and, therefore, more highly keratinized tissue. It was suggested that decreased sensitivity to SLS by the older group may be linked to hormonal changes as well as a slowing in the turnover rate of mucosal cells. Although tissue is thinner in older women, all layers are evident, thus leading to the conclusion that the tissue becomes more compact, which may explain a reduced risk of tissue irritation.

Effect of `tartar control`

Tartar-control toothpastes contain the anti-tartar chemical pyrophosphate, as well as flavoring agents which have been implicated in tissue sloughing and a burning sensation. To test this connection, researchers compared tartar-control toothpastes and non-tartar-control toothpastes on a large group of dental students and dental hygiene students.

Four toothpastes were tested over a 14-week period. More oral lesions were associated with the two tartar-control toothpastes than with the two non-tartar-control pastes. Questionnaires filled out by the students revealed a taste preference for the non-tartar-control pastes and a higher rate of burning sensation associated with the tartar-control toothpastes.

The link between tartar-control toothpaste and superficial mucocele development also has been found in younger patients, specifically college students. These lesions appear as clear, fluid-filled superficial vesicles which rupture within a few hours, leaving behind small areas of desquamation. Complete healing usually occurs within a couple of days. Patients may complain of a single or several "sore spots" which appear every few days or weeks and heal within a couple of days. If tartar-control toothpaste is being used, its elimination may alleviate the problem.

The case of an older patient with oral lesions was reported by researchers at the University of Southern California Dental School. They examined a 71-year-old woman who previously had consulted 20 health-care specialists over a period of two years for multiple, painful, fluid-filled lesions on her soft palate, retromolar regions, and buccal and lower labial mucosa. The lesions generally appeared after breakfast and the pain was relieved by puncturing the lesions with finger pressure. A variety of diagnosis were made over this time and the patient tried many treatments and medications, but the lesions continued unchecked.

Finally, it was suggested that the patient refrain from using tartar-control toothpaste. This simple remedy controlled the irritation, with only an occasional lesion appearing on the soft palate.

Next time you encounter oral irritation and painful lesions of unknown origin, ask about toothpaste use. Simply refraining from toothpaste use may solve the problem. If toothpaste is the cause, a week without it will give you the answer.

References available upon request.

Trisha E. O`Hehir, RDH, is a senior consulting editor of RDH. She also is editor of Perio Reports, a newsletter for dental professionals that addresses periodontics.