Figure 1e: Grandio Seal placement and light-curing

Caries prevention: Practical products and proven approaches

March 4, 2020
Carla Cohn, DMD, looks at some of the most effective caries prevention modalities—remineralization of enamel, exposure to fluoride, use of xylitol, and placement of sealants—and a group of products from Voco that can be used as part of these modalities.

According to Merriam-Webster, the definition of prevention is “the act of preventing or hindering.”1 Caries is a condition that can be prevented, as it is the symptom of a disease. It is the endpoint of the infection of cariogenic bacteria and the action of that infection on the body. When thinking about caries risk management, the goal is preventing caries from developing at all.

It is true that preventing is better than curing. This is not a novel idea—in fact, Thomas Edison has been credited with saying, “The doctor of the future will give no medication, but will interest his patients in the care of the human frame, diet, and in the cause and prevention of disease.”2 A very wise statement. Yet, as dental professionals, we continue to struggle with prevention. Caries is alive and well, and in certain sectors of the population, it is rising in prevalence.3 Some may say it is even rising in severity. In order to stop caries, preventive protocols and modalities must be provided to our patients at the earliest opportunities.

Primary–primary prevention, that which is provided to the expectant parents, is both the truest form of prevention and the most effective.4 For an expecting couple, it is paramount to offer caries education, preventive strategies, and protective factors before the child arrives. This keeps the child from being exposed to cariogenic bacteria. This is critical, as early acquisition of cariogenic bacteria is a major risk factor for future caries.5–7 

The opportunity to provide primary prevention can be challenging, and despite our efforts, infection by cariogenic bacteria can still occur. Given this, much of our preventive effort must rely upon controlling the highest risk factors. This includes evaluating patients’ diets, as well as counseling on oral hygiene, managing exposure to fluoride, use of calcium and phosphate, and applying sealants.

We will now look in more detail at some of the most effective caries prevention modalities—remineralization of enamel, exposure to fluoride, use of xylitol, and placement of sealants—and a group of products that can be used as part of these modalities.


Caries prevention starts with enamel integrity. Enamel is made up of a form of hydroxyapatite (HA) that consists of calcium, phosphate, and a hydroxyl end-member. HA is known to dissolve at a pH of 5.5, a point known as the “critical pH” of enamel.8 This means that dissolution begins at pH 5.5 and when enamel is exposed to bacteria and a fermentable carbohydrate source for those bacteria. When this happens, calcium and phosphate precipitate, resulting in a white-spot lesion. If left unchecked, the caries cycle continues and a frank lesion follows.

Enamel will demineralize with a loss of calcium and phosphate. Alternatively, it will remineralize with an abundance of calcium and phosphate. As described by John Featherstone, PhD, there is a remineralization-demineralization balance in our mouths.9 Factors that increase the possibility of demineralization increase caries risk, and factors that enhance remineralization decrease caries risk. Enamel integrity is affected accordingly.

As described by Colin Dawes, BDS, PhD, whom I had the honor of learning from as a young dental student, there can, in fact, be variation in the critical pH of enamel. Dr. Dawes notes, “The critical pH does not have a fixed value, but rather is inversely proportional to the calcium and phosphate concentrations in the solution.”10 Additionally, when teeth that have lesions are treated at an early stage (that is, prior to loss of tooth structure), they can be remineralized.10 Thus, if our goal is to maintain the mineral content of HA, calcium and phosphate must be available for uptake into the enamel.

There are a number of products on the dental market that provide calcium and phosphate to remineralize enamel. Some examples include:

• nano-hydroxyapatite,

• amorphous calcium phosphate,

• casein phosphopeptide and amorphous calcium phosphate in combination, and

• calcium sodium-phosphosilicate (Novamin).

Nano-hydroxyapatite (calcium and phosphate), a substance that consists mainly of hydroxyapatite, is the active ingredient in Remin Pro (Voco GmbH). This product allows for calcium and phosphate ions to adhere to the tooth surface. Additionally, Remin Pro can release calcium and phosphate for remineralizing enamel, sealing dentinal tubules, and smoothing surface irregularities. The mechanism is through use of a synthetic enamel that rapidly repairs early caries demineralization by nanocrystalline growth.11,12 Remin Pro contains two additional critical protective factors: 1,450 ppm fluoride and xylitol. Fluoride makes enamel harder, and xylitol is a noncariogenic sugar substitute that contributes to fluoride’s effectiveness.


The composition of HA can be changed if enamel is exposed to and uptakes fluoride, as the hydroxyl end-member is substituted with a fluoride ion. This changes HA to fluorapatite or fluorhydroxyapatite.13,14 In doing so, enamel becomes harder and more resistant to acid attack. The critical pH changes from 5.5 to 4.5, allowing for an extra “degree” of acid attack before dissolution occurs.

Fluoride exposure in the form of fluoride varnish has been accepted as highly effective, particularly in children. Compared to sound enamel, demineralized enamel uptakes a greater amount of fluoride. The mechanism of action for uptake is twofold. First, firmly bound fluoride is incorporated onto tooth surface structure. Second, loosely bound fluoride, which has the ability to act as a reservoir and enhance mineralization of adjacent tooth structure, reduces the solubility of tooth mineral and therefore inhibits demineralization.15,16

Studies show that fluoride varnish application is effective in reducing caries. Fluoride varnish is most effective when applied biannually and in conjunction with dietary management and oral hygiene counseling for at least two years. These approaches begin no later than one year of age.17,18

Profluorid Varnish (Voco GmbH) is a 22,600 ppm (5%) fluoride varnish. Even with this seemingly high dosage of fluoride, the risk of ingestion is lower than with fluoride gel application and similar to that of brushing with a fluoridated dentifrice.19–21 Profluorid Varnish is simple to apply, either with a brush or the finger, and treatment can be completed in a few seconds. It is transparent when applied, adherent to moist surfaces, has excellent flowability, and has high immediate fluoride release. Flowability is extremely important, as not all surfaces that are at risk are easily accessible to place varnish. Varnish must be able to flow where it is needed.


Xylitol is a five-carbon sugar alcohol derived primarily from forest and agricultural materials. Xylitol, as well as other sugar alcohols, is not readily metabolized by oral bacteria, and thus is considered a noncariogenic sugar substitute. Xylitol studies show varying results in the reduction of the incidence of caries. The famous Turku studies showed a dramatically reduced decayed, missing, filled score (DMF) for xylitol gum chewers versus sucrose gum chewers.22 Because xylitol is not fermented by bacteria, acid is not produced, and therefore pH is not decreased, demineralization is prevented, and remineralization is enhanced. Over time, xylitol can reduce the accumulation of plaque on the surface of the tooth, resulting in the bacterial makeup of the plaque changing and allowing for fewer and fewer cariogenic bacteria to survive. Use caution, however, as xylitol can cause upset stomach in some patients and is lethal for dogs.

Dental sealants

Dental sealants are an effective tool for preventing caries. They physically obstruct pits and fissures, preventing penetration and colonization of cariogenic bacteria and any fermentable carbohydrate food source.

The American Academy of Pediatric Dentistry and American Dental Association recommend the following guidelines for sealants:

• placement on surfaces based upon patient’s risk, 

• careful cleaning of pits and fissures without removal of any appreciable enamel, 

• diligent follow-up care,

• use of a bonding layer, and

• use of glass ionomer sealants as transitional sealants.23

Many sealant materials are available, and many have excellent properties. The choice of sealant material should include properties that allow for greatest success, including a highly filled material, low slumping, high flowability, and fluoride release. One product that has these properties is Grandio Seal (Voco GmbH). The fill content of Grandio Seal is 70%, which translates clinically into a sealant that has great wear, can withstand occlusal forces, and does not shrink considerably (which leads to the best retention). Flowability permits penetration to both small and deep pits and fissures. Fluoride release protects not only the tooth being sealed, but also makes fluoride available to adjacent teeth.24

Sealant placement techniques should include complete isolation and an intermediary bonding layer (figure 1).25–29 The bonding layer and sealant curing can be one of two different methods: either placement and light-curing simultaneously in a simplified sealant technique or separately. Evidence-based studies show results favoring the individual light-curing technique in cases where conditions are dry and noncontaminated. In cases where there is saliva contamination, bond strength was the same in either simultaneous or individual light-cure placement methods.30–31


When patients have achieved a cavity-free checkup, it is gratifying for them and rewarding for us. As dental professionals, we have a toolbox available to help patients achieve and maintain health. Great products, combined with education and motivation, can give us the results our patients deserve.


  • Prevention. Merriam-Webster website. Accessed February 3, 2019.
  • Thomas A. Edison Quotes. Goodreads website. Accessed February 3, 2019.
  • Rozier RG, White BA, Slade GD. Trends in oral diseases in the U.S. population. J Dent Educ. 2017;81(8):eS97-eS109. doi:10.21815/JDE.017.016.Koch G, Poulsen S, Twetman S. Caries prevention in child dental caries. Koch G, Poulsen S, eds. In: Pediatric Dentistry. A Clinical Approach. Copenhagen: Handelshøjskolens Forlag. 2001;119-145.Köhler B, Andréen I, Jonsson B. The earlier the colonization by mutans streptococci, the higher the caries prevalence at 4 years of age. Oral Microbiol Immunol. 1988;3:14-17.Alaluusua S, Renkonen OV. Streptococcus mutans establishment and dental caries experience in children from 2 to 4 years old. Scand J Dent Res. 1982;91:453-457.Thenisch NL, Bachmann LM, Imfeld CT, Leisebach Minder T, Steurer J. Are mutans streptococci detected in preschool children a reliable predictive factor for dental caries risk? A systematic review. Caries Res. 2006;40(5):366-374.Barron RP, Carmichael RP, Marcon MA, Sàndor GKB. Dental erosion in gastroesophageal reflux disease. J Can Dent Assoc. 2003;69(2):84-89.Featherstone JDB. The science and practice of caries prevention. J Am Dent Assoc. 2000;131(7):887-899.Dawes C. What is the critical pH and why does a tooth dissolve in acid? J Can Dent Assoc. 2003;69(11):722-724.Roveri N, Battistella E, Bianchi CL, et al. Surface enamel remineralization: biomimetic apatite nanocrystals and fluoride ions different effects. J Nanomaterials. 2009. L, Pan H, Tao J, et al. Repair of enamel by using hydroxyapatite nanoparticles as the building blocks. J Mater Chem. 2008;18(34):4079-4084.Sköld-Larsson K, Modéer T, Twetman S. Fluoride concentration in plaque of adolescents after topical application of different fluoride varnishes. Clin Oral Investig. 2000;4(1):31-34.ten Cate JM, Featherstone JD. Mechanistic aspects of the interactions between fluoride and dental enamel. Crit Rev Oral Biol Med. 1991;2(3):283-296.White DJ, Nancollas GH. Physical and chemical considerations of the role of firmly and loosely bound fluoride in caries prevention. J Dent Res. 1990;69(2):587-594.Lippert F, Anderson TH, Martinez-Mier EA, Zero DT. Laboratory investigations into the potential anticaries efficacy of fluoride varnishes. Pediatr Dent. 2014;36(4)291-295.Weintraub JA, Ramos-Gomez F, Jue B, et al. Fluoride varnish efficacy in preventing early childhood caries. J Dent Res. 2006;85(2):172-176.Lawrence HP, Binguis D, Douglas J, et al. A 2-year community-randomized trial of fluoride varnish to prevent early childhood caries in aboriginal children. Community Dent Oral Epidemiol. 2008;36(6):503-516.Roberts JF, Longhurst P. A clinical estimation of the fluoride used during application of a fluoride varnish. Br Dent J. 1987;162(12):463-466.Ekstrand J, Koch G, Petersson LG. Plasma fluoride concentrations in pre-school children after ingestion of fluoride tablets and toothpaste. Caries Res. 1983;17(4):379-384.Ekstrand J, Koch G, Lindgren LE, Petersson LG. Pharmacokinetics of fluoride gels in children and adults. Caries Res. 1981;15(3):213-220.Scheinin A, Mäkinnen KK, Ylitalo K. Turku sugar studies. V. Final report on the effect of sucrose, fructose and xylitol diets on the caries incidence in man. Acta Odontol Scand. 1976;34(4):179-216.American Academy of Pediatric Dentistry and American Dental Association. Evidence-based clinical practice guideline for the use of pit-and-fissure sealants. Pediatr Dent. 2016;38(5):263-279.Alsaffar A, Tantbirojn D, Versluis A, Beiraghi S. Protective effect of pit and fissure sealants on demineralization of adjacent enamel. Pediatr Dent. 2011;33(7):491-495.Feigal RJ, Musherure P, Gillespie B, Levy-Polack M, et al. Improved sealant retention with bonding agents: A clinical study of two-bottle and single-bottle systems. J Dent Res. 2000;79(11):1850-1856.Hebling J, Feigal RJ. Use of one-bottle adhesive as an intermediate bonding layer to reduce sealant microleakage on saliva-contaminated enamel. Am J Dent. 2000;13(4):187-191.McCafferty J, O’Connell AC. A randomised clinical trial on the use of intermediate bonding on the retention of fissure sealants in children. Int J Paediatr Dent. 2015;26(2):110-115.Ataol E, Ertan A, Cehreli ZC. Sealing effectiveness of fissure sealants bonded with universal adhesive systems: influence of different etching modes. J Adhes Sci Technol. 2016;31(14):1-9.Bagherian A, Shirazi AS, Sadeghi R. Adhesive systems under fissure sealants: yes or no? A systematic review and meta-analysis. J Am Dent Assoc. 2016;147(6):446-456.Torres CP, Balbo P, Gomes-Silva JM, Ramos RP, et al. Effect of individual or simultaneous curing on sealant bond strength. J Dent Child. 2005;72(1):31-35.Gomes-Silva JM, Torres CP, Contente MMMGC, et al. Bond strength of a pit-and-fissure sealant associated to etch-and-rinse and self-etching adhesive systems to saliva-contaminated enamel: individual vs. simultaneous light curing. Braz Dent J. 2008;19(4):341-347.

    Carla Cohn, DMD, is a general dentist who has devoted herself solely to the care of pediatric patients. Her private practice, Kids Dental, is focused on the growth and development of a cavity-free generation. She is also a part-time clinical instructor at the University of Manitoba College of Dentistry and founding member of the Women’s Dental Network in Winnipeg, Manitoba.

    Disclosure: Dr. Carla Cohn is a key opinion leader for Voco GmbH. The products cited in this article are used in her course of everyday practice.