Clinical evaluation of three desensitizing agents in relieving dentin hypersensitivity

Howard E. Strassler, DMD

Commentary by Howard E. Strassler, DMD

Pamir T, Dalgar H, Onal B. Oper Dent. 2007;32(6): 544-548.

OBJECTIVES: This in-vivo study determined whether the application of three different desensitizing agents on exposed dentin surfaces was effective in reducing dentin hypersensitivity in subjects with slight-to-moderate sensitivity. METHODS: Sixty patients with a history of sensitivity were included in this study. At baseline visit the initial sensitivity levels were recorded using a visual analog scale (VAS). In order to activate the sensitivity, evaporative (air-blast) and thermal (chloraethyl) stimuli were applied to each subject. The subject’s responses to the stimuli were marked on the VAS. Then, the subjects were assigned to one of the treatment groups or to a placebo. The agents used were Seal&Protect (Dentsply DeTrey GmbH, Konstanz, Germany), VivaSens (Ivoclar Vivadent AG, Schaan, Lichtenstein), and BisBlock (Bisco, Schaumburg, IL); whereas, distilled water was used as the placebo. The subjects were recalled after four weeks, and their responses recorded again. RESULTS: The VAS scores of the treatment and placebo groups were not different from each other at baseline (P > .05), and thermal stimuli caused higher patient discomfort than evaporative stimuli (P < .05). Alleviation effects of the desensitizing agents were not significantly different from each other, however, the placebo was an exception (P < .05). The differences between the VAS scores at baseline and after four weeks were significant for all three desensitizing agents (P < .05). However in the placebo group, the evaporative stimuli led to insignificant pain variations (P > .05). CONCLUSION: It was concluded that the desensitizing agents used in this clinical study were effective in alleviating dentin hypersensitivity. Meanwhile, the placebo response was shown to play a significant role.

COMMENTARY

Every day in practice the clinician encounters at least one patient with sensitive teeth. Dentinal hypersensitivity refers to a sharp, sudden pain when teeth are exposed to a stimulus. This stimulus can be tactile, exposure to hot and cold food and beverages, exposure to breathing in cold air, or even brushing and/or flossing. No vital tooth in the mouth is immune to dentinal hypersensitivity. Root sensitivity has been reported in incisors, canines, premolars, and molars. The prevalence of dentinal hypersensitivity has been reported to be between 4% and 57% in the general population. Among periodontal patients, the frequency of tooth hypersensitivity is considerably higher (60% to 98%).

The prevalence of dentin hypersensitivity is so great that there is an entire selection of toothpastes that are primarily marketed for treating sensitivity. Manufacturers constantly make claims about their products being superior to others. These two studies present some of what we already know, but it is still important to see it verified with clinical trials: professionally dispensed desensitizing agents work at reducing dentin hypersensitivity. Most times the sensitivity is not completely eliminated, and even when it is, there is a high likelihood of recurrence, which means re-treatment of the sensitive area. Is there one product or treatment that works best?

In the Fiocchi study, patients who had root sensitivity after periodontal therapy were treated with amorphous calcium phosphate (which promotes deposition and clogging of the dentinal tubules) compared to treatment with neutral sodium fluoride. Both products were applied following the manufacturers’ instructions for in-office application. No additional at-home treatment was recommended. In this study there was no difference between the test (ACP) and the control treatment (sodium fluoride) in reducing root sensitivity after scaling and root planing. What was interesting was that ice applied to the buccal surfaces produced the greatest sensitivity. For both products there was a reduction of sensitivity, with the greatest reductions at week 3 and week 4. Also, the study noted prevalence of sensitivity from different teeth: the most prevalent tooth with sensitivity was No. 3 followed by Nos. 6 and 14.

In the Pamir study, all three in-office desensitizing agents clogged the dentinal tubules: one product with a light-cured resin, the other two with precipitation products. The manufacturers’ instructions were followed. Four weeks after application, all three products exhibited similar effects and alleviated dentin hypersensitivity. What was of interest in this study was a significant reduction to the thermal stimulus for the placebo product.

These studies provide valuable information in our dental practices for the treatment of dentin hypersensitivity. It was disappointing that neither study recalled the patients at 6 months or 1 year to provide data on the long-term effectiveness of the treatments. Desensitizing toothpastes (usually with an active ingredient of 5% potassium nitrate) have been demonstrated in many studies to be effective pain reducers. Using an in-office product such as the ones tested, combined with a recommended sensitivity toothpaste, may be the best route for clinical treatment. Patients also need to understand that there is no one-shot treatment that eliminates the pain forever. Dentin hypersensitivity is a chronic condition that must be re-treated on a regular basis to achieve reductions in sensitivity, making eating and breathing at extreme temperatures more bearable.

Howard E. Strassler, DMD
Professor and Director of Operative Dentistry
Department of Endodontics, Prosthodontics and Operative Dentistry
University of Maryland Dental School, Baltimore, Maryland