Is dentinal hypersensitivity a minor issue affecting a handful of patients? Disappointingly, the answer is no. Research data reveals 57% of the general population suffers from dentinal hypersensitivity with that frequency being considerably higher (60%–98%) in periodontal patients.1 Studies suggest dentinal hypersensitivity peaks between the ages of 20 to 40 with a slightly higher prevalence in women.2 Dentinal hypersensitivity impacts quality of life and emotional well-being.3
Clinical management of dentinal hypersensitivity is possible. Ideally, recognition of the causative agent will allow the clinician to reduce dentinal hypersensitivity by simple methods, including diet modification and brushing techniques.4 Other methods include decreasing the porosity of dentin through the application of at-home desensitizing agents, which is accomplished by depolarization of the nerve or occlusion of the dentinal tubules.4,5 When at-home desensitizing agents prove to be ineffective, patients can benefit from in-office desensitization therapy. Of all the in-office therapies listed, fluoride varnish has become the most commonly used and has proven to be highly effective in reducing dentinal hypersensitivity.
Fluoride varnish is a concentrated form of sodium fluoride (NaF) suspended in an alcohol- and resin-based solution and is approved by the Food and Drug Administration (FDA) for use as a cavity liner and desensitizer.6,7
Currently there are an estimated 49 varnish products on the market. The physical composition of fluoride varnishes is similar. The vast majority of varnishes are composed of 5% NaF. Dosage for children ages 6 years and under is 2.25%. All varnishes contain a film-forming agent (e.g., colophony), a solvent, flavors, sweeteners, and other additives that aid in remineralization (e.g., calcium, casein phosphopeptide, amorphous calcium phosphate, calcium fluoride).8
Solvents impact the viscosity, spreadability, migration, solubility, and fluoride ion release profile of varnishes, thereby impacting their behavior. Calcium additives are important in varnishes because they affect the bioavailability of fluoride, which ultimately impacts varnish performance.
How does fluoride varnish work?
Once varnish is applied to the tooth surface, the fluoride ions are absorbed into the hard tissues, stick to areas of the tooth that have been demineralized, and integrate with hydroxyapatite.9 The fluoride ions are also attracted to the calcium and phosphate ions in the saliva and form a crystalline structure called fluorapatite.10 Fluorapatite has a lower solubility profile than hydroxyapatite, which allows the ions to disassociate and become bioavailable at a lower pH.9,10
Indications for fluoride varnish
Fluoride varnishes are preferred as an in-office treatment because they are quick and easy to use. Fluoride varnishes eliminate the need for trays, making them ideal for young children and patients prone to gagging. Fluoride varnishes also come in various flavors, which helps to increase patient acceptability for infants, toddlers, preschoolers, and children with special needs. There are some disadvantages associated with the use of fluoride varnish, including its tacky feeling on the tooth surface, yellowish tint, and cost.
How to select a varnish
With so many varnish products on the market, how do you pick just one? Fluoride uptake is a key feature for varnishes and helps to determine the effectiveness of the product. Ideally a fluoride varnish should exhibit fluoride uptake 24 hours after an acid challenge.9
Some of the most common varnishes on the market include Duraphat (Colgate), MI Varnish (GC America), 3M Vanish, and Profluorid (Voco). These products are similar in that they aid in the treatment of hypersensitivity, enhance remineralization, and inhibit caries formation. But they differ because of the additives included in an attempt to increase their effectiveness.10
Voco’s Profluorid Varnish is transparent and the only varnish product to contain xylitol, which has a proven cariostatic effect and taste-enhancing properties. Profluorid Varnish is also moisture tolerant, so drying of the treatment area is not necessary, making application very efficient.11 Its unique formulation allows patients to experience immediate relief in sensitive areas with a high yield of fluoride on the treated surface.11 Profluorid Varnish sets within seconds of application and has enhanced flow characteristics, which allows the product to reach areas conventional varnishes may miss.12 Due to its low film thickness, patient acceptance is higher and application by the clinician is faster and easier.
This varnish also has flavors that appeal to both younger patients and adults: bubble gum, cherry, mint, caramel, and melon. In July 2020, Voco released a new flavor, cola lime. It is ideal for patients with allergies, since it does not contain tree nuts, peanuts, corn, shellfish, eggs, milk protein, soy, gluten, triclosan, petroleum, red dye/artificial coloring, saccharin, or aspartame, and is manufactured in a nut-free facility.12
For patients allergic to colophony-based varnishes and those who want the benefits of a varnish without the sticky feeling, Voco offers a liquid varnish. Profluorid L is the only liquid varnish on the market. It is specially formulated with a synthetic resin matrix, so it does not interfere with the bleaching process.13 In fact, this product can be used before, during, and after the bleaching process to ensure maximum patient comfort during treatment. Profluorid L is also great to use before periodontal debridement for patients who are hypersensitive. It has a thin, clear, liquid consistency for easy application without the stickiness. Profluorid L’s composition contains 5% NaF and calcium additives that create the ideal formula for immediate and long-term relief of sensitivity.
As clinicians, it is important that we understand the science behind what we select and offer to our patients. This is the premise behind evidence-based dentistry. While varnishes are similar in their mechanism of action, they do not all behave the same because of the additives, solvents, and matrixes incorporated into their formulations. It is critical to have a solid understanding of how a varnish behaves in order to measure its effectiveness.9 The second part of this article series will explore additional treatment modalities for dentinal hypersensitivity.
Editor’s note: This article is sponsored by Voco. Content has been reviewed for editorial integrity per RDH guidelines. For more information on our editorial standards, see rdhmag.com/page/submission-guidelines.
- Strassler HE. Dentinal hypersensitivity: Dilemmas and treatment. American Dental Assistants Association. April 2019. https://adaa.cdeworld.com/courses/21338-dentinal-hypersensitivity-dilemmas-and-treatment
- Trushkowsky RD. Etiology and treatment of dentinal hypersensitivity. Decisions in Dentistry. December 8, 2016. https://decisionsindentistry.com/article/etiology-treatment-dentinal-hypersensativity/
- Sensitivity: Overview. GSK. https://www.gskhealthpartner.com/en-us/oral-health/conditions/sensitivity/overview
- Longridge NN, Youngson CC. Dental pain: dentine sensitivity, hypersensitivity and cracked tooth syndrome. Prim Dent J. 2019;8(1):44-51. doi:10.1177/205016841900800101
- Miglani S, Aggarwal V, Ahuja B. Dentin hypersensitivity: Recent trends in management. J Conserv Dent. 2010;13(4):218-224. doi:10.4103/0972-0707.73385
- Bowen DM, Pieren JA. Darby and Walsh Dental Hygiene. 5th ed. Elsevier: 2019.
- Picano L. Fluoride varnishes: What is the difference, and which one is best? Dental Economics. April 1, 2020. https://www.dentaleconomics.com/science-tech/cosmetic-dentistry-and-whitening/article/14173399/fluoride-varnishes-what-is-the-difference-and-which-one-is-best
- Chandak S, Bhondey A, Bhardwaj A, Pimpale J, Chandwani M. Comparative evaluation of the efficacy of fluoride varnish and casein phosphopeptide–amorphous calcium phosphate in reducing Streptococcus mutans counts in dental plaque of children: An in vivo study. J Int Soc Prev Community Dent. 2016;6(5):423-429. doi:10.4103/2231-0762.192936
- Klaiber P. Varnish solutions: Making sense of all the options. Presented at: The American Dental Hygienists’ Association Annual Session; June 26-28, 2020.
- Pajor K, Pajchel L, Kolmas J. Hydroxyapatite and fluorapatite in conservative dentistry and oral implantology—a review. Materials (Basel). 2019;12(17):2683. doi:10.3390/ma12172683
- Voco Profluorid Varnish information sheet. Voco. https://www.voco.dental/en/portaldata/1/resources/products/folders/gb/voco-profluorid-varnish_fol_gb.pdf
- Voco Profluorid Varnish product page. Voco. https://www.voco.dental/us/products/preventive-care/fluoride-varnish/voco-profluorid-varnish.aspx
- Dental catalog. Voco. https://www.voco.dental/portaldata/1/Resources/e-paper/dental-programme/us/offline/download.pdf
Joy D. Void-Holmes, DHSc, BSDH, RDH, is a hygienist with 25 years of clinical experience, founder of Dr. Joy, RDH, and creator of the Dental Hygiene Student Planner. She is program chair of the Fortis College dental hygiene program, holds a faculty position at the American Denturist School, and is a professional speaker and published author. She has presented continuing education courses nationally and internationally in the areas of instrumentation, ultrasonics, infection control, nutrition, and biochemistry, along with her signature keynote, Confidence and Courage.