Fluoride

The overconsumption of toothpaste has negative consequences, particularly for children. This study’s objectives were to describe misleading marketing strategies used in selling children’s fluoridated toothpaste and identify warning label characteristics. Two researchers independently coded the packaging from 26 over-the-counter toothpastes that are specifically marketed for children. Aggressive marketing strategies targeting children were identified: every toothpaste in this sample displayed at least 1 children’s animated character, 50% had at least 1 picture of a food item, 92.3% stated they were flavored and 26.9% depicted a full swirl of toothpaste, directly contradicting dentist recommendations for young children. Further, on most toothpaste tubes, warnings regarding fluoride overconsumption for young children were only listed on the back and in very small font. Misleading marketing strategies are regularly used in selling children’s toothpaste as if it is a food product, while warnings regarding overconsumption among youth are minimized. Dental hygienists are in an important position to help parents of young children implement safe oral care practices.

BACKGROUND:
Fluoride is delivered to the teeth systemically or topically to aid in the prevention of dental caries. Systemic fluoride from ingested sources is in blood serum and can be deposited only in teeth that are forming in children. Topical fluoride is from sources such as community water, processed foods, beverages, toothpastes, mouthrinses, gels, foams, and varnishes. The United States Centers for Disease Control and Prevention (CDC) and the American Dental Association (ADA) have proposed changes in their long standing recommendations for the amount of fluoride in community drinking water in response to concerns about an increasing incidence of dental fluorosis in children. Current research is focused on the development of strategies to improve fluoride efficacy. The purpose of this update is to inform the reader about new research and policies related to the use of fluoride for the prevention of dental caries.

METHODS:
Reviews of the current research and recent evidence based systematic reviews on the topics of fluoride are presented. Topics discussed include: updates on community water fluoridation research and policies; available fluoride in dentifrices; fluoride varnish compositions, use, and recommendations; and other fluoride containing dental products. This update provides insights into current research and discusses proposed policy changes for the use of fluoride for the prevention of dental caries.

CONCLUSIONS:
The dental profession is adjusting their recommendations for fluoride use based on current observations of the halo effect and subsequent outcomes. The research community is focused on improving the efficacy of fluoride therapies thus reducing dental caries and lowering the amount of fluoride required for efficacy.

A double-blind randomized clinical trial was performed in 6- to 7-yr-old schoolchildren to evaluate, in a 30-mo period, whether the caries increment on the distal surface of the second primary molars adjacent to permanent first molars sealed with fluoride release compounds would be lower with respect to those adjacent to permanent first molars sealed with a nonfluoridated sealant. In sum, 2,776 subjects were enrolled and randomly divided into 3 groups receiving sealants on sound first molars: high-viscosity glass ionomer cement (GIC group); resin-based sealant with fluoride (fluoride-RB group); and a resin-based sealant without fluoride (RB group). Caries (D1 – D3 level) was recorded on the distal surface of the second primary molar, considered the unit of analysis including only sound surfaces at the baseline. At baseline, no differences in caries prevalence were recorded in the 3 groups regarding the considered surfaces. At follow-up, the prevalence of an affected unit of analysis was statistically lower (p = .03) in the GIC and fluoride-RB groups (p = .04). In the GIC group, fewer new caries were observed in the unit of analysis respect to the other 2 groups. Incidence rate ratios (IRRs) were 0.70 (95% confidence interval: 0.50, 0.86; p < .01) for GIC vs. RB and 0.79 (95% confidence interval: 0.67, 0.89; p = .005) for fluoride-RB vs. RB [Corrected]. Caries incidence was significantly associated with low socioeconomic status (IRR = 1.18; 95% confidence interval: 1.10, 1.42; p = .05). Dental sealant high-viscosity GIC and fluoride-RB demonstrated protection against dental caries, and there was evidence that these materials afforded additional protection for the tooth nearest to the sealed tooth (clinical trial registration NCT01588210).

Fluorine is the world’s 13th most abundant element and constitutes 0.08% of the Earth crust. It has the highest electronegativity of all elements. Fluoride is widely distributed in the environment, occurring in the air, soils, rocks, and water. Although fluoride is used industrially in a fluorine compound, the manufacture of ceramics, pesticides, aerosol propellants, refrigerants, glassware, and Teflon cookware, it is a generally unwanted byproduct of aluminium, fertilizer, and iron ore manufacture. The medicinal use of fluorides for the prevention of dental caries began in January 1945 when community water supplies in Grand Rapids, United States, were fluoridated to a level of 1 ppm as a dental caries prevention measure. However, water fluoridation remains a controversial public health measure. This paper reviews the human health effects of fluoride. The authors conclude that available evidence suggests that fluoride has a potential to cause major adverse human health problems, while having only a modest dental caries prevention effect. As part of efforts to reduce hazardous fluoride ingestion, the practice of artificial water fluoridation should be reconsidered globally, while industrial safety measures need to be tightened in order to reduce unethical discharge of fluoride compounds into the environment. Public health approaches for global dental caries reduction that do not involve systemic ingestion of fluoride are urgently needed.

RESULTS:
Micro-CT examination revealed a superficial opaque band approximately 150μm on the arrested cavitated dentinal lesion. This band was limited in the active carious lesion. EDX examination detected a higher intensity of calcium and phosphate of 150μm in the surface zone than in the inner zone, but this zone was restricted in the active cavitated dentinal lesion. SEM examination indicated that the collagens were protected from being exposed in the arrested cavitated dentinal lesion, but were exposed in the active cavitated dentinal lesion. TEM examination suggested that remineralised hydroxyapatites were well aligned in the arrested cavitated dentinal lesion, while those in the active cavitated dentinal lesion indicated a random apatite arrangement.

CONCLUSIONS:
A highly remineralised zone rich in calcium and phosphate was found on the arrested cavitated dentinal lesion of primary teeth with an SDF application. The collagens were protected from being exposed in the arrested cavitated dentinal lesion.

CLINICAL SIGNIFICANCE:
Clinical SDF application positively influences dentine remineralisation.

BACKGROUND:
Fluoride additives contain metal contaminants that must be diluted to meet drinking water regulations. However, each raw additive batch supplied to water facilities does not come labeled with concentrations per contaminant. This omission distorts exposure profiles and the risks associated with accidents and routine use.

OBJECTIVES:
This study provides an independent determination of the metal content of raw fluoride products.

METHODS:
Metal concentrations were analyzed in three hydrofluorosilicic acid (HFS) and four sodium fluoride (NaF) samples using inductively coupled plasma-atomic emission spectrometry. Arsenic levels were confirmed using graphite furnace atomic absorption analysis.

RESULTS:
Results show that metal content varies with batch, and all HFS samples contained arsenic (4·9-56·0 ppm) or arsenic in addition to lead (10·3 ppm). Two NaF samples contained barium (13·3-18·0 ppm) instead. All HFS (212-415 ppm) and NaF (3312-3630 ppm) additives contained a surprising amount of aluminum.

CONCLUSIONS:
Such contaminant content creates a regulatory blind spot that jeopardizes any safe use of fluoride additives.

In 2011, EPA released new risk and exposure assessments for fluoride. The agency announced its intent to use this science and additional research to review the primary and secondary drinking water standards for fluoride and to determine whether to revise them. To make a regulatory determination, EPA also must consider analytical methods for testing for fluoride at lower concentrations, treatment feasibility (including cost), occurrence, and exposure.

This in vitro study was undertaken to evaluate the caries-preventive effect of three orthodontic band cements (a dual-curing resinmodified glass ionomer cement [RMGIC] and two light-curing polyacid-modified composite resin [compomer] cements) in terms of fluoride release, retentiveness, and microleakage after thermocycling. The RMGIC (Ortholy Band Paste [GC Ortholy, Inc., Tokyo, Japan]) showed a significantly higher amount of cumulative fluoride release over 180 days (p<0.001) and significantly greater tensile bond strength (p<0.001) than the compomer cements (Transbond Plus [3M Unitek, Monrovia, CA, USA] and Ultra Band-Lok [Reliance Orthodontic Products, Inc., Itasca, IL, USA]). Its bond strength was unaffected by thermocycling (2,000 cycles), indicating good retentiveness, whereas that of the compomer cements significantly decreased after thermocycling. Moreover, it had lower dyepenetration scores, indicative of less microleakage. These findings suggest that the RMGIC may have a better caries-preventive effect than the compomer cements and is suitable for long-term orthodontic banding.

OBJECTIVE:

To provide a brief commentary review of fluoride-containing toothpastes and mouthrinses with emphasis on their use at home. Toothpastes and mouthrinses are just two of many ways of providing fluoride for the prevention of dental caries. The first investigations into incorporating fluoride into toothpastes and mouthrinses were reported in the middle 1940s. Unlike water fluoridation (which is ‘automatic fluoridation’), fluoride-containing toothpastes and fluoridecontaining mouthrinses are, primarily, for home use and need to be purchased by the individual. By the 1960s, research indicated that fluoride could be successfully incorporated into toothpastes and clinical trials demonstrated their effectiveness. By the end of the 1970s, almost all toothpastes contained fluoride. The widespread use of fluoride- containing toothpastes is thought to be the main reason for much improved oral health in many countries. Of the many fluoride compounds investigated, sodium fluoride, with a compatible abrasive, is the most popular, although amine fluorides are used widely in Europe. The situation is similar for mouthrinses. Concentrations of fluoride (F), commonly found, are 1500 ppm (1500 μg F/g) for toothpastes and 225 ppm (225 μg F/ml) for mouthrinse. Several systematic reviews have concluded that fluoride-containing toothpastes and mouthrinses are effective, and that there is added benefit from their use with other fluoride delivery methods such as water fluoridation. Guidelines for the appropriate use of fluoride toothpastes and mouthrinses are available in many countries.

CONCLUSION:

Fluoride toothpastes and mouthrinses have been developed and extensive testing has demonstrated that they are effective and their use should be encouraged.