Dental caries, although preventable, remains a challenge for practicing dental professionals. From to , 13.4% of children and adolescents ages 3 to 19 had active or untreated caries and 22.8% of adults ages 20 to 74 had untreated tooth decay.1 The caries process involves demineralization of the calcified tooth structures with a breakdown of the organic matrix.2 While the process is multifactorial, Streptococcus mutans remains the main culprit. This microorganism populates the tooth surface and penetrates through the tooth-layered structures during favorable conditions, such as in presence of the fermentable carbohydrates.3
Click here to get more.
Through periods of demineralization and remineralization on the tooth's exterior, the metabolic processes of acidogenic bacteria begin to penetrate the enamel layer, dissolving the calcium and phosphate minerals from the structure.4 For clinicians, managing caries requires collaboration with the patient to support remineralization with adjunctive therapies, such as fluoride, and minimize habits contributing to demineralization.
Fluoride's effectiveness is based on its ability to inhibit the acidogenic process of bacteria, preventing demineralization at the tooth's surface and enhancing remineralization.5 Fluoride disrupts biofilm by penetrating it and interfering with acid production. With a decrease in the pH of dental biofilm, fluoride ions join with hydrogen ions creating the compound HF, which then disperse into the bacterial biofilm. HF's diffusion inside the biofilm leads to the release of additional fluoride ions that inhibit bacterial metabolism.6
Once fluoride accumulates in the biofilm, the pH levels within it decrease and the bacteria then require more energy exertion, effectively slowing down the progression of biofilm growth and acidogenic processes.5 Fluoride concentration is highest at the enamel's surface, with 3,000 parts per million (ppm) in fluoridated areas and 1,000 to 2,000 ppm in nonfluoridated areas. The presence of adsorbed fluoride in the fluid surrounding the crystal structure of the tooth surface serves as a protective barrier against cariogenic activity.4
After demineralization begins on the enamel surface, the structure is able to absorb more fluoride than on an intact surface, as the fluoride incorporates into the hydroxyapatite crystalline structure.2 Remineralization of the tooth involves adding calcium and phosphate back to the affected surface. By bathing the demineralized surfaces with mineral-rich saliva, the pH rises, offsetting cariogenic activity to levels that enable remineralization to occur.6 The introduction of fluoride enhances the attraction of calcium and phosphate to the tooth's surface. Fluoride achieves this by forming a thickened layer on the crystal surface, which draws calcium and phosphate ions.2 This process illustrates the dynamic balance between demineralization and remineralization, as phosphate and calcium ions move in and out of the tooth's outer structure.4
For remineralization to occur, calcium and phosphate must be reincorporated into the tooth's structure. Saliva and its components, particularly proline-rich proteins, assist in both creating a protective layer on the tooth's surface and bringing calcium ions to the tooth to enhance remineralization.7 If the pH maintains a neutral level, saturation with the necessary ions occurs more quickly, enabling remineralization to begin.
Saliva plays a critical role in maintaining oral health by buffering pH levels during resting saliva production.8 Additionally, its ability to deliver fluoride to the tooth's outer layer for remineralization highlights saliva's importance in preventing dental caries.9 The buffering capacity of saliva and the immunoglobulin defense factors further highlight saliva's importance for the health of the oral microbiota.8
Various biological components impact not only salivary flow, but also the organic or inorganic makeup of saliva.10 Thus, clinicians should thoroughly evaluate the presence of saliva when recommending fluoride therapies to maximize the potential for remineralization.
The adoption of minimally invasive dentistry has shifted caries management away from surgical interventions to relatively low-cost, less-invasive interventions such as fluoride application.11 Fluoride recommendations are based on individual caries risk assessments, in which specific concentrations are recommended for patients at low, medium, and high risk.2 A personalized assessment must include the presence of any active carious lesions; modifiable risk factors, such as diet; and protective factors related to daily biofilm control.12
Patients at low caries risk have adequate health literacy; acceptable oral hygiene habits, including the daily use of an over-the-counter (OTC) fluoride toothpaste; a healthy diet low in fermentable carbohydrates; and effective biofilm removal regimen.2 Patient education should encourage and reinforce these behaviors. Patients should consume optimally fluoridated water of 0.7 ppm and use OTC fluoride toothpastes with lower ppm concentrations.2
Many patients drink only bottled water, thus eliminating the potential benefits of community water fluoridation. The benefits vs risks of consuming fluoridated water should be part of patient education. Brushing with toothpastes containing 1,000-1,100 ppm of fluoride decreases the number of decayed, missing and filled surfaces (DMFS) when compared to brushing with nonfluoride toothpastes.13 For patients at low caries risk, supplemental fluoride therapies at higher concentrations are not necessary. Studies reveal limited evidence on the benefits of prescription or professionally applied fluoride therapies in a low caries risk individual.14
Moderate caries risk indicates an increase in risk factors, tipping the balance away from protective factors and creating an environment more conducive to caries development. Patient education should focus on meticulous biofilm removal and increasing protective factors. Individuals with moderate caries risk benefit from oral hygiene instructions and nutritional counseling.2 These methods in conjunction with fluoride therapies have the potential to maximize remineralization and prevent caries development.
Research suggests that higher concentrations of fluoride may have a greater impact on remineralization of tooth surfaces.15 Self-applied fluoride mouthrinses in concentrations ranging from 230 ppm to 900 ppm are effective when used regularly in combination with effective biofilm removal.16 Mouthrinses with 0.05% sodium fluoride inhibit caries by disrupting the cariogenic processes on the tooth's surface.17 Research shows the use of fluoride mouthrinse decreases DMFS by 27% in permanent teeth.16
The use of mouthrinses requires active patient compliance for optimal remineralization and caries prevention.17 Patients at moderate caries risk unable to comply may benefit from more frequent maintenance appointments and professionally applied fluoride therapies at higher concentrations.15
Patients at high or severe risk for caries require proactive approaches and collaboration between the dental team and the patient. The effectiveness of fluoride for high caries risk depends on merging antibacterial and fluoride therapies to offset the bacterial processes and maximize opportunities for remineralization.18 Evidence indicates the use of OTC fluoride products in lower concentrations (1,000-1,100 ppm) is inadequate for caries prevention in high-risk patents.2 Thus the clinician must implement evidence-based treatments according to the severity of disease and risk level to promote remineralization.
Those at high caries risk individual should have 5% NaF varnish professionally applied, brush with 5,000 ppm fluoride toothpaste twice daily, use chlorhexidine gluconate 0.12% mouthrinse once daily each month for 1 week, and consume xylitol products daily.18 The 5% NaF varnish contains 22,600 ppm of concentrated fluoride, with biannual application reducing incidence of caries by up to 43% in the permanent dentition.2,12 Patients at high risk should receive varnish applications three to four times per year.2 Some research shows that more frequent intervals for varnish application are more effective in both the primary and permanent dentition.19 Future studies should focus on establishing a more standardized protocol.
Prescription toothpastes with 5,000 ppm of fluoride show significantly greater surface remineralization and inhibition of demineralization when compared to toothpastes with 1,500 ppm or less.15 Toothpastes with 5,000 ppm of fluoride remain in saliva for longer periods of time. A study evaluating salivary fluoride with different toothpaste concentrations identified higher levels of available salivary fluoride after just 3 weeks of use with the 5,000 ppm formulations.20 The available salivary fluoride dropped within days upon switching to lower concentration toothpastes within the same study. Patient compliance and consistency of use are necessary for effectiveness.
Since receiving approval from the United States Food and Drug Administration in for dentinal hypersensitivity, silver diamine fluoride (SDF) has demonstrated efficacy in preventing and treating caries. The most common formulation contains 255,000 ppm of silver ions for their antibacterial properties and 44,800 ppm of fluoride ions to enhance remineralization and decrease demineralization.21
When in contact with the hydroxyapatite crystals on the tooth's surface, the free calcium and fluoride react to create calcium fluoride (CaF2) and silver phosphate.22 SDF provides effective antimicrobial properties capable of disrupting the acidogenic processes of S. mutans, Actinomyces naeslundii, and Lactobacillus acidophilus.
SDF provides clinicians with an effective option for addressing patient anxiety and discomfort while also arresting active lesions in a simple application. The straightforward, noninvasive application of SDF requires minimal training and only basic supplies, and produces no aerosols during application.21
Jabin et al22 found that individuals who received SDF had higher levels of fluoride concentration when compared to those who received fluoride varnish. The well-defined benefits of SDF come with minor side effects, such as staining. Once placed on any demineralized lesion of dentin or enamel, the treated surface turns dark in color, indicating the success of the treatment.22 This requires thorough patient education on the benefits of the procedure prior to placement.
Research shows the application of SDF arrested active lesions in children at high caries risk and older adults with root caries.23 In a 30-month study on the effectiveness of varying concentrations of SDF on active caries in the primary dentition found that the application of 38% SDF had was the most successful at arresting lesions.24 Additionally, researchers found a relationship between biofilm reduction and SDF effectiveness. Children with higher scores on the Visible Plaque Index were less likely to have lesions arrested after SDF application.24 This finding confirms the importance of daily, mechanical biofilm removal in managing dental caries and the role of the dental hygienist in preventive patient education. For children, this requires collaboration between caregivers and the dental team. Current evidence identifies the use SDF as a preventive agent alone or in conjunction with other therapies for older adults at risk for root caries.23 Further studies on the clinical application of SDF should examine its use in prevention and treatment of root caries in addition to studying different types of adult populations.
YongYing supply professional and honest service.
The ability of fluoride to remineralize surfaces, inhibit demineralization, and disrupt bacterial processes related to caries development cement its importance in dentistry. The various modalities for application and delivery of fluoride provide the clinician with numerous options for individualized patient recommendations. The effectiveness of fluoride products must coincide with the patient's caries risk level.
Patient assessment should also evaluate individuals' readiness to assist in their own fluoride delivery. Patients with special needs or those who are medically complex may need additional support. Those with limited dexterity, mobility concerns, or swallowing abilities may need more potent professionally applied concentrations.15 Regardless of the type of fluoride chosen for prevention, any dental caries management plan should include patient education on the need for daily, frequent mechanical biofilm removal to maximize caries prevention.
Editor's note: Originally posted in and updated regularly
Fluoride's effectiveness in preventing tooth decay and dentinal hypersensitivity is well known. Fluoride treatments are supported by the World Health Organization, the Centers for Disease Control and Prevention (CDC), as well as many other agencies. Fluoridation of public water is considered to be one of the most successful public health acts in the fight against dental decay, according to the CDC.1 There are numerous types of professional fluoride applications that can be provided in the dental office as treatment for adults and children. The American Dental Association recognizes 5% sodium fluoride (NaF) or 2.26% fluoride content varnish treatment for the benefit of caries prevention when given at least twice per year to children up to age 18.2 Sodium fluoride varnishes are also recommended for prevention of root caries in adults when administered at least twice a year at patients' prophylaxis appointments. It is easily interpreted that fluoride varnishes are beneficial to all age groups, especially children and individuals with high caries risk.3 So, what is the best type of varnish, and what are the differences between the various topical fluoride treatments?
Currently, we have no studies to support the clinical benefits of one type of professional fluoride treatment over another. It has been shown that the frequency and duration of tooth-to-fluoride contact are the greatest contributors to the success of a treatment modality. When comparing fluoride carriers such as varnish to toothpaste and rinse, there are no proven benefits of a specific delivery system.4 So, why a varnish, and what should we look for in one?5
As a delivery system, varnish is preferred for its ease of use, prolonged fluoride exposure time, and relative safety. A concern with other carrier modalities is that there is an increased risk of ingestion, as well as decreased contact time with the teeth. Most varnishes on the market contain 5% NaF with an alcohol- and resin-based solution. The evaporation of the alcohol makes the system fast drying, and the resin functions to allow the fluoride to adhere to the teeth. The most common resin additive is colophony, a rosin derived from pine tree sap. The carrier is the cause of the main complaint about varnish, in that it is 'sticky' and leaves a noticeable film on the teeth.2
You might also be interested in: 3 ways hygienists can boost acceptance of fluoride varnish
Not all products are created equal, as science has developed different additives to place in varnishes in an attempt to increase their effectiveness. Following is a comparison of some of the most common varnishes on the market.
Duraphat (Colgate) was the first varnish on the market in . This varnish contains 5% NaF suspended in an alcohol-based solution of natural resins. Duraphat varnish is tinted; this is reported to be for easy visualization. The product has a high viscosity.
MI Varnish (GC America) is unlike any other varnish. It contains 5% NaF + Recaldent (CPP-ACP). Recaldent is a novel combination of casein phosphopeptide (CPP) and amorphous calcium phosphate (ACP). The casein peptide naturally occurs in milk and binds to teeth in the oral cavity, mucosa, and even biofilm, which allows the ACP to be stabilized until it reaches the teeth to recalcify tooth structures.7 MI paste and Recaldent have been greatly studied and proven to be an effective way to remineralize teeth.
Fluor Protector S (Ivoclar Vivadent) is different in that it contains 1.5% ammonium fluoride (NH4F). This varnish uses ethanol and water as solvents to allow for a decreased viscosity and increased wetting and flowability. After the solvent evaporates, the fluoride concentration is up to four times higher on the tooth surface, providing 3% fluoride content locally. To increase efficacy, a polymer additive helps the varnish to adhere to the teeth. Its transparency, homogeneity, and thin viscosity provide a high level of patient acceptance and satisfaction.8
Kolorz ClearShield (DMG America) contains 5% NaF. This varnish, as named, goes on completely clear for an esthetic appearance. This product works to improve the varnish experience with its many different flavor choices, such as watermelon, bubblegum, mint, cookie dough, and caramel, making each varnish treatment more enjoyable.
Vanish Varnish (3M) is a unique product in that it is proven to release fluoride over the course of 24 hours. As we have read, one of the greatest indicators of a fluoride treatment's effectiveness is its duration. The longer the duration of contact with the fluoride, the greater effect it can have on teeth. Another unique component of this product is that it has tricalcium phosphate, in addition to the NaF, to help with the remineralization of teeth. This varnish is an alcohol-based suspension of modified rosin. The product reports an increased flowability and a decreased film thickness.9 Another major advantage of this varnish is its effectiveness on polished and unpolished teeth, as well as in wet or dry environments. The product's extended release is a great advantage too.
References
1. Water fluoridation basics. Division of Oral Health. National Center for Chronic Disease Prevention and Health Promotion. Centers for Disease Control and Prevention website. https://www.cdc.gov/fluoridation/basics/index.htm. Updated January 24, . Accessed February 17, .
2. Professionally applied topical fluoride: Evidence-based clinical recommendations. J Am Dent Assoc. ;137(8):-. doi:10./jada.archive..
3. Weyant RJ, Tracy SL, Anselmo TT, et al. Topical fluoride for caries prevention: Executive summary of the updated clinical recommendations and supporting systematic review. J Am Dent Assoc. ;144(11):-. doi:10./jada.archive..
4. Marinho VCC, Higgins JPT, Sheiham A, Logan S. One topical fluoride (toothpastes, or mouthrinses, or gels, or varnishes) versus another for preventing dental caries in children and adolescents. Cochrane Database Syst Rev. (1):CD. doi:10./.CD.pub2
5. Karlinsey KL. Fluoride varnishes: Why they work & what to look for. EC Dent Sci. ;5(6):-.
6. Martel S. A new generation of fluoride varnish is coming to you. Oral Health Group website. https://www.oralhealthgroup.com/features/new-generation-fluoride-varnish-coming/. Published September 14, .
7. GC America proudly introduces MI Paste & MI Paste Plus. Frequently asked questions. GC America MI Paste Family website. http://www.mi-paste.com/FAQ_MIP.php.
8. Fluor Protector S. Ivoclar Vivadent website. https://www.ivoclarvivadent.com/en/p/all/fluor-protector-s.
Want more information on Fluoride Manufacturers? Feel free to contact us.