BY PARAG R. KACHALIA, DDS
Each and every day numerous patients complain about tooth sensitivity to their dentist or hygienist. In fact, some studies show that nearly 50% of the patient population has some extent of tooth sensitivity.1 Some of these patients may be fearful of even having a prophylaxis completed because they fear the procedure itself may incite further discomfort. Many patients may have sensitive teeth due to significant issues such as caries or tooth fractures that require surgical restorative treatment; however, many others may have more simple issues that can be managed by some of the many chemical therapeutics that are available to dental professionals.
This article will examine the various therapies available today and provide guidance to practitioners so that they can maximize their patients' comfort levels. The primary focus will be to provide strategies to combat sensitivity; however, sensitivity often goes hand in hand with caries as well as erosion. The options presented here can also be very helpful for patients who show signs of medium to high caries risk, as well as help slow the progression of tooth decay and put patients on the road to good oral health.
Fluoride varnish-Sodium fluoride in-office therapy has been around for many years and has taken numerous forms ranging from rinses to foams and, most recently, to varnishes. Over the last decade, many practitioners have moved away from the traditional rinses and foams, and instead concentrated their efforts on applying fluoride varnish. Foams and rinses were very messy and also exhibited a poor taste at times. The actual fluoride release of these products was marginal at best, and patient compliance was poor. To combat these issues, practitioners and the dental industry created fluoride applications via varnish. Varnishes have significant contact time and release of fluoride ions. Numerous research projects have examined the benefits of fluoride varnishes, and there is clear evidence that the application of varnishes at least twice per year provides a substantial benefit for caries prevention in both children and adults.2
In many practices, fluoride varnish is used routinely on children from a prevention standpoint; however, fluoride varnishes should also be considered for adults who show signs of caries risk and/or have teeth that exhibit sensitivity. Many times patients may come for a hygiene appointment complaining about sensitivity or may even exhibit signs of sensitivity after a prophylaxis or scaling and root planing treatment. Sodium fluoride varnish should be considered as the first line of defense in these cases. Such varnishes can help treat areas that exhibit root exposure, cervical defects, and even enamel defects.
Products such as Voco's Profluorid Varnish have a 5% sodium fluoride concentration, as opposed to a 2% concentration that is available in fluoride foams and gels. This concentration allows a substantial fluoride release to occur and helps soothe the patient's discomfort. In addition to having a high fluoride release, a varnish must also be easy to apply and maintain appropriate contact to the tooth surface upon which it is applied. Profluorid Varnish has a chemistry that contains a material called colophony, a derivative of tree rosin.
Once the tooth or teeth have been cleaned, the varnish can be applied and stays in place even if the teeth are moist, as the colophony within Profluorid Varnish sets up immediately upon contact with saliva. If the varnish were easily diluted, the effectiveness of the varnish would diminish. After the material is applied, it is best to have patients run their tongue over their teeth (all three surfaces) to help set the varnish and spread the fluoride. In the presence of saliva, sodium fluoride tends to dissolve quickly and can easily be taken up by the dentinal tubules, thus promoting a decrease in sensitivity. In addition, excess fluoride ions can bind to calcium ions that are available in saliva and provide long-term protection from acidic attacks. It's noteworthy that calcium fluoride can ultimately help with the formation of fluorapatite, which is shown to be more resilient to the caries process.3
Liquid varnish-Today, many patients seek out tooth-whitening procedures to obtain a brighter smile that they can be proud of. An
unfortunate side effect of whitening procedures, however, is that the dentition can become very sensitive both during and after whitening. In some cases, patients may avoid whitening altogether if they have had a history of sensitivity and do not want things to get worse. This type of sensitivity is generally stimulated near the gumline and is also common in patients who have had recession or margins of restorations placed onto cementum.
Many initial therapies, including over-thecounter sensitivity toothpastes are available; however, these therapies tend to mask the issue versus solving the underlying problem. Many over-the-counter products simply add potassium nitrate, which acts as a low-level, temporary anesthetic to the tooth, and no physical healing actually occurs. Many of these potassium nitrate products offer only short-term relief to patients in terms of sensitivity reduction.4 On the other hand, dental professionals have products available that can be applied to the dentition and actually solve sensitivity for a much longer period of time. One such product is Profluorid L Varnish by Voco.
Unlike traditional fluoride varnishes, this product has a synthetic resin matrix and is a true liquid. By having a synthetic resin matrix this product is essentially color free and can be combined with whitening therapy and may even open the door to those who avoided whitening for fear of having overly sensitive teeth. Similar to traditional varnishes, sodium fluoride plays a large role in the chemistry; however, Profluorid L also contains both sodium fluoride and calcium fluoride deposits, so the chemistry of each of these compounds is maximized.
Sodium fluoride provides a short-term effect as it is easily dissolved. When large amounts of fluoride are present, calcium fluoride is formed. Unlike the sodium fluoride, it is not easily dissolved and a precipitate occurs. Calcium fluoride then diffuses into the dentinal tubules and helps seal them, decreasing sensitivity. These calcium deposits almost act as a reservoir and can release fluoride over the long run. This dual chemistry innovation allows for a short- as well as a long-term benefit.
In clinical practice, Profluorid L can be applied to all root surfaces that may come in contact with any potential whitening agent, both before whitening is started as well as after. In addition, the product can work very well around existing restorative margins and can simply be painted on once the tooth surface is cleaned and dried. After applying the material, a light air drying of the liquid is all that is needed.
Tooth cream-Another product that can offer a tremendous benefit to patients who have sensitivity or a high caries rate is a tooth cream that can be applied via toothbrush, finger, or bleaching tray. One key benefit of this type of therapy is that the cream can be applied at home by patients themselves, so sustained action of the active ingredients is much more possible. Remin Pro tooth cream by Voco has three active ingredients to protect as well as repair tooth structure that has been compromised: (1) fluoride, (2) hydroxyapatite, and (3) xylitol.
Sodium fluoride has been discussed in great detail and its mechanism via tooth cream is similar to the in-office products presented, but the actual concentration of sodium fluoride is 1,450 ppm versus 22,600 ppm, evident in fluoride varnishes. This lower concentration is intentional in that patients apply the tooth cream at home over multiple cycles; thus a single large boost of fluoride is not needed.
One key ingredient of Remin Pro is nano-hydroxyapatite (nHAP). This ingredient is essentially a combination of calcium and phosphate ions, which actually helps rebuild tooth structure. This nanostructure fills small irregularities and helps protect against erosion and demineralization. These nanostructures also help occlude dentinal tubules and decrease sensitivity. The smooth surface that is formed as a result of nHAP makes the adhesion of dental plaque more difficult. Of particular note is that nHAP even seems to work well in the presence of biofilm, which can be very difficult to penetrate.5
The third active ingredient in Remin Pro is xylitol. Over the years, research has been mixed as to whether xylitol aids in remineralization, but it is clear that xylitol does not support the growth of cariogenic bacteria, which lowers the proliferation of Streptococcus mutans. Some research also shows that with long-term use, Lactobacilli are also reduced. At the bare minimum, xylitol has been shown to provide a smooth surface to which plaque is less likely to stick.
Tooth creams such as Remin Pro work very well in a tray-type delivery. Practitioners may want to consider offering a product like this, especially after whitening procedures. The soft plastic trays that are used to deliver whitening peroxides also work very well in delivering tooth creams after whitening is completed. A recent study showed that when Remin Pro was applied for five minutes twice a day for 15 consecutive days, the dentition was significantly less rough compared to those teeth that have been whitened and have no follow- up treatment.6
Dentistry has evolved greatly, and we now have many therapies available to help prevent discomfort and disease. In this article, three products were discussed, ranging from modalities that are primarily focused on in-office use to those that depend on patients' home care. Each of these therapies can decrease the amount of sensitivity our patients experience and help manage the caries process over time. Some patients may have a very low caries risk in which only one or two teeth are sensitive and a fluoride liquid application can be a tremendous difference. Other patients may have a higher caries risk with extensive sensitivity issues that require restorative therapy in conjunction with one or more of the preventive regimens described. Thankfully, options are available today so that the entire dental team can work together to help patients have an enhanced level of oral health. RDH
Parag R. Kachalia, DDS, is vice chairman of simulation, technology, and research within the University of the Pacific's esthetic rehabilitation program. He is a fellow of the American Dental Education Association's leadership institute, as well as a published author in digital dental photography, digital fixed prosthodontics, and financial management.
REFERENCES
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2. Marinho VC, Worthington HV, Walsh T, Clarkson JE. Fluoride varnishes for preventing dental caries in children and adolescents. Cochrane Database Syst Rev. 2013;7:CD002279. doi: 10.1002/14651858.CD002279.pub2.
3. Takagi S, Liao H, Chow LC. Effect of tooth-bound fluoride on enamel demineralization/remineralization in vitro. Caries Res. 2000;34:281-8.
4. Satyapal T, Mali R, Mali A, Patil V. Comparative evaluation of a dentifrice containing calcium sodium phosphosilicate to a dentifrice containing
potassium nitrate for dentinal hypersensitivity: a clinical study. J Indian Soc Periodontol. 2014;18(5):581-5.
5. Zhang M, He LB, Exterkate RAM, et al. Biofilm layers affect the treatment outcomes of NaF and nano-hydroxyapatite J Dent Res. 2015;94(4):602-607.
6.Heshmat H, Ganjkar MH, Jaberi S, Fard MJ. The effect of Remin Pro and MI Paste Plus on bleached enamel surface roughness. J Dent (Tehran). 2014;11(2):131-6.
