FLUORIDES. What is fluoride? Fluoride is the ionic form of the element fluorine. It is negatively...

FLUORIDES

What is fluoride?

• Fluoride is the ionic form of the element fluorine.• It is negatively charged and will not remain as a free

element.• Fluoride has a high affinity for calcium.

– It is, therefore, very compatible with teeth and bone.

Mechanisms of Action

• Topical• Systemic • Antibacterial


• Topical– inhibits demineralization

– promotes remineralization


• Fluoride’s role in remineralization– When bacteria metabolize carbohydrate and produce acid,

fluoride is released from dental plaque in response to lower pH levels at the tooth interface (Tatevossian, 1990).

– To be more acid resistant and contain more fluoride and less carbonate, the demineralized enamel crystal structure takes up released plaque fluoride and salivary fluoride along with calcium phosphate.


• The pH in the oral cavity falls within seconds of ingestion of dietary sugars.

• The pH can stay low for up to two hours.

• Low pH leads to demineralization of the tooth structure.

• When pH returns to normal/neutral, remineralization can occur.

• The original mineral apatite structure of teeth is rich in carbonate, has relatively little fluoride and is relatively soluble.

• Cycles of partial demineralization and remineralization in a fluoride-rich environment can create fluoride-rich, low-carbonate apatite, which is up to 10X less soluble than the original apatite structure.

RemineralizationDemineralization

Remineralization Demineralization


• Systemic– improves enamel crystallinity

– reduces acid solubility

– improves tooth morphology (controversial)


• Several studies have reported that teeth formed in fluoridated communities or exposed to fluoride supplements pre-eruptively tend to be smaller and have shallower pits and fissures than teeth formed in non-fluoridated communities or not exposed to pre-eruptive fluoride supplements (Lovius et al, 1969; Simpson, et al, 1969; Aasenden, et al, 1974).

• These researchers believe that even if the differences are small and do not entirely explain lower caries prevalence, the very fact that measurable alterations in tooth morphology occur when there is pre-eruptive exposure to fluoride indicates that there must be some effect from exposure to fluoride during tooth development.


• Antibacterial– concentrates in plaque

– disrupts enzyme systems• Fluoride inhibits bacterial metabolization of carbohydrates to

produce acid and affects the bacterial production of adhesive polysaccharides (Hamilton, 1990).

• When fluoride is constantly present, mutans Streptococci produce less acid (Bowden, 1990).

Pre-eruptive vs. Post-eruptive Fluoride

• Pre-eruptive fluoride exposure = systemic fluoride exposure

• Post-eruptive fluoride exposure = topical fluoride exposure

According to the CDC 2001 Recommendations for Using Fluoride to Prevent and Control Dental Caries in the United States (at the website), “. . .laboratory and epidemiologic research. . .indicates that fluoride’s predominant effect is post-eruptive and topical.”

HOWEVER. . .

• Clinical epidemiologic data demonstrate both pre- and post-eruptive caries-preventive benefits to teeth from fluoride.

A recent report showed that pre-eruptive exposure to fluoride in Australian children 6 to 15 years old was required for a caries-prevention effect in first permanent molars and that exposure to fluoride after eruption alone did not alter caries level significantly (Singh, et al, 2003).

Maximal caries-preventive effects of fluoridated water were achieved by high pre- and post-eruption exposure.

Summary of Anti-Caries Activity of Fluoride

1. Fluoride prevents demineralization.

2. Fluoride enhances remineralization.

3. Fluoride alters the action of plaque bacteria.

4. Fluoride aids in posteruptive maturation of enamel.

5. Fluoride reduces enamel solubility.

Fluoride--A Brief Glimpse into History--

• Fluoride’s ability to inhibit or even reverse the initiation and progression of dental caries is well documented.

• The first use of adjusted fluoride levels in water supplies for caries control began in 1945 and 1946 in the United States and Canada.

• The first field study occurred in four pairs of cities—Grand Rapids and Muskegon, MI; Newburgh and Kingston, NY; Evanston and Oak Park, IL, and Brantford and Sarnial, Ontario Canada.

• Sequential cross-sectional surveys were conducted over the next 13 to 15 years.


• The findings included:– a reduction in caries of 50 to 70% in children with fluoridated water

supplies.

• As a result, in the 1940s, 1950s, and again in 1962, the U.S. Public Health Service (PHS) developed recommendations regarding fluoride concentrations in public water supplies.

• The recommendations occurred after patterns of water fluoridation and caries experience across different climates and geographic regions in the U.S. were studied through epidemiologic investigations.

• Depending on climate, the recommended range of water fluoridation varied from 0.7 to 1.2 parts per million (ppm).


• The success of water fluoridation in preventing and controlling dental caries led to the development of fluoride-containing products, including toothpaste, mouth rinse, dietary supplements, and professionally applied or prescribed gel, foam, or varnish.

• In addition, processed beverages, which constitute an increasing proportion of the diets of many U.S. residents, and food can contain small amounts of fluoride, especially if they are processed with fluoridated water.


• Benefits of fluoride– Fluoride helps to prevent tooth decay.

• People with non-fluoridated water supplies continue to demonstrate higher rates of decay.

• A 15 year landmark study in Grand Rapids, MI showed that children who had fluoridated water from birth had a 50 to 63% decrease in tooth decay.

• In 1993, the results of 113 studies in 23 countries were compiled and analyzed. The review included 66 studies in primary teeth and 86 studies in permanent teeth. Together the decay reductions were:

» 40 to 49% for primary teeth

» 50 to 59% for permanent teeth


A comprehensive analysis of the 50 year history of community water fluoridation in the U.S. demonstrated that the inverse relationship between higher fluoride concentration in drinking water and lower levels of dental decay continues to be true today.


• Water fluoridation is cost effective.

• Per person, it costs on average $ .50-1.00 per year.

• Water fluoridation is especially beneficial for low socioeconomic communities where there is a disproportionate burden of decay and less access to dental care and other fluoride sources.

• Fluoride is safe and effective.

• Nearly 100 national and international organizations including the ADA, USPHS, AMA, APA, AFP, IADR, the National PTA, the ACS, and WHO endorse optimal fluoridation of community water.

• The ADA has endorsed water fluoridation as safe and effective for over 40 years.

Water Fluoridation

Surgeon General David Satcher wrote in his report, Oral Health in America,

“Community water fluoridation is safe and effective in preventing dental caries in both children and adults. Water fluoridation benefits all residents served by community water supplies regardless of their social or economic status.”

Status of Community Water Fluoridation in the United Sates

• Fluoridated water is currently provided in 10,500 U.S. communities.• 145 million U.S. residents currently benefit from fluoridation.• 62% of the population served by community water system are provided

optimum levels of fluoride.• In 2000, a total of 38 states and the District of Columbia provided access to

fluoridated water supplies to greater than 50% of their population.• Kentucky was one of the first states to mandate that all community water

supplies had to be fluoridated. Kentucky continues to be a leader in the percentage of the public water supplies fluoridated.

*Centers for Disease Control and Prevention, Division of Oral Health Fluoridation Census, 1992 and 2000.

Fluoride--Other Sources--

• Types of fluorides– In the United States, there are three types of fluorides

approved by the FDA as safe and effective for use in dentifrices:

• Sodium fluoride (for use in paste, must be bound to another element or it will bind to the abrasive ingredient)

• Sodium monofluorophosphate (holds fluoride in complex form and is released when exposed to phosphatase enzyme in the mouth)

• Stannous fluoride (was the first used in dentifrice, was previously difficult to stabilize, has gingivitis-reduction properties, but has an astringent taste and potential staining)


• Fluorides for Professional Use– FDA approved for professional use:

• Acidulated phosphate fluoride (APF) with 1.23% (12,300 ppm)


• Fluorides for Professional Use (continued)– FDA approved for professional use:

• APF

• Neutral sodium fluoride (NaFl) with 2% (9,000 ppm)


• Fluorides for Professional Use (continued)– FDA approved for professional use:

• APF

• NaFl

• Stannous fluoride (SnFl) with 8% (not used routinely for topical semi-annual applications)


• Fluoride Varnish– There is strong evidence for the use of fluoride varnish for

caries control of permanent teeth, but the evidence for primary teeth is, while promising, inconsistent and incomplete (IOM Report, 2000).

– NaFl varnish delivers 2.26% fluoride (22,600 ppm), the strongest concentration of fluoride delivered.

– Application stays on tooth surface 4 to 6 hours after application (product is purposely colored to detect presence)


• Fluoride Varnish (continued)– Effectiveness thought to be the result of substantial

increase in fluorine content of the tooth surface and subsurface enamel

– Fluoride varnish has been used since late 1960 in Europe and Canada as a primary preventive agent, with as much as a 75% reduction in decay (GoranKock, 1975).

– Fluoride in varnish also gradually dissolves into the plaque, saliva, and enamel providing bacteriocidal, bacteriostatic, and remineralizing effects (Nelson, 1984).


• Fluoride Varnish (continued)– No toxic effects were found in the blood plasma levels in preschool

and school children after treatment with varnish. The use of varnishes is, therefore, safer than gels with small children (Ekstrand, 1981). Children younger than six years of age tend to swallow 30 to 50% of gel products (LeCompte, 1987).

– The FDA has cleared fluoride varnish as a cavity liner or root desensitizer. All other uses are currently considered “off-label”!

– After 2 ½ years, fluoride varnish resulted in a higher percentage of caries reduction than 2% NaFl solution or 1.23% APF gel (Tewart, 2000).


• Which varnish do we currently use at UKCD?

CavityShield

Fluoride in Prophy Paste

• Contains 4,000 to 20,000 ppm• May replace the concentration of fluoride removed by

polishing, but does not adequately substitute for fluoride gel or varnish in treating high risk caries patients (Stookey, 1995).


• Fluoride for Home Use– Home delivery modalities

• Neutral sodium fluoride– .05% (225 ppm) –rinse

– .2% (1,000 ppm) –Rx rinse

– 1,000 – 1,500 ppm –Regular over the counter paste

– 1.1% (5,000 ppm) –Rx paste

» Example: Prevident 5000


• Fluoride for Home Use (continued)– Home delivery modalities

• Acidulated phosphate fluoride– .044% (1,100 ppm) –rinse

– 5,000 ppm –Rx gel

• Stannous fluoride– 3,000 ppm –Rx gel

– .63% --Rx rinse


• Fluoride Dentifrices– Best topical application for compliance

– Ingestion: 0.2 to 0.3 mg can be swallowed by pre-school aged children when brushing twice a day

– Recommendations/instructions for use• Fluoride dentifrice (>90% use in U.S.)

• Very small, pea-sized amount in pre-school aged children

• Parents must supervise small children

• Rinse and expectorate following brushing

Comments on the Efficacy of Fluoride

• The greatest preventive benefits are gained at fluoride levels that are greater than or equal to 1,500 ppm of NaFl with frequent applications (Vernon, 1992).

• As little as 1 to 3 ppm affects acid production.– Bacteriostatic at 250 ppm– Bacteriocidal at 1000 ppm (Van Leuveren, 1990)

• Use of regimens according to their individual risk level yields greater probability of success and better cost effectiveness than applying identical treatments to all patients independent of risk levels (Anusavice, 2001).

• Due to fluoridated water and fluoride toothpaste, the salivary level of fluoride between brushing is thought to be 0.2 to 0.8 ppm (Duckwork, 1991).

Comments on the Efficacy of Fluoride

• For children with low risk of dental caries (reference risk assessment criteria previously discussed) “professional topical fluoride applications are not likely to be cost effective.” (Consensus conference of fluoride usage—see website for link.)

• Topical fluorides can be expected to prevent 0.03-0.26 decayed surfaces per year, but only if applied every six months.

• Topical fluorides are not recommended as a routine therapy for children at low risk for caries who live in a fluoridated community, due to their relatively low cost-benefit effectiveness.

• Topical fluorides have their greatest effect on smooth surface enamel. Their impact on caries prevention is significantly less on fissures due to the impaction of plaque in fissures. The clinical relevance of this is that it is critically important that in applying a topical fluoride it be carried inter-proximally (to the most susceptible smooth surfaces of teeth) with dental floss.

Fluoride and Anticipatory Guidancefor the Pediatric Dental Patient

• Early childhood appointments provide a stage for discussion of family water use, fluoride-vitamin combinations, introduction and prudent use of fluoridated dentifrice and the inappropriateness of mouth rinses for the very young.

• Timely patient education prior to the high fluorosis risk period between 22 and 36 months of age may minimize inappropriate fluoride use and fluorosis (Den Besten, 1994).


• In evaluating daily fluoride exposures for young children, the use of filters that may remove fluoride from city and well water must be addressed.

• Water testing services exist at the Kentucky State Department of Health.

• Most commercial infant water contains 1 ppm of fluoride.

• Other bottled water brands may have fluoride concentrations in varying amounts; the information should be verified by documentation requests to the particular bottling company.


• Core components of anticipatory guidance for the very young should include:– Encouragement for use of optimally fluoridated water

– Minimal dentifrice per use

– Professional supplementation subsequent to water testing

Fluoride Supplementation ScheduleFluoride Content of Water

Adapted from American Academy of Pediatric Dentistry Handbook, 1999

AGE <0.3 ppm 0.3 – 0.6 ppm >0.6 ppm

6 months – 3 years 0.25 mg/day -- --

3 years – 6 years 0.50 mg/day 0.25 mg/day --

6 years – 16 years 1.00 mg/day 0.50 mg/day --

Prescribing Fluoride Supplements

• Select doses: age, water F status (based on water analysis)

• Select supplement: drops, tablets, lozenge, rinse• Write prescription: specific directions; maximize 120

mg per Rx• Educate parent and patient

Pertinent Issues

• Dose/frequency—effectiveness (low dose, high frequency is current “best” use of F)

• Bottled water (variable fluoride content, may vary seasonally and with manufacturer)

• Filtration systems: point of use system can reduce fluoride

• Prenatal use (not shown effective)• Formula (0.1 – 0.3 ppm on average for both soy and

milk-based formulas)

Fluoride Supplementation Prescriptions--Examples--

• 8-Month-Old Residing in a Fluoride-Deficient AreaRx: Sodium fluoride solution (0.125 mg F/drop)

Disp.: 40 mgSig.: Before bed time dispense 2 drops of liquid in mouth

• 6-Year-Old Residing in a Fluoride-Deficient AreaRx: Sodium fluoride tablets (1 mg F/tablet)

Disp.: 120 tabletsSig.: Before bed time after a thorough brushing, chew one tablet, swish, and swallow

Fluoride Supplementation Prescriptions--Examples--

• High Caries Risk PatientRx: NaF Gel (0.5% F)Disp.: (varies depending on product)Sig.: Brush on fluoride gel once/twice daily instead of toothpasteExample: Prevident 5000

The Fluorosis Issue

• Fluorosis is a permanent intrinsic white-to-brown discoloration of enamel.

• Increase in prevalence due to ambient fluoride.

• Sources of ingested fluoride– Diet/ “halo” effect from foods, beverages

– Dentifrice consumption

– Previous supplementation schedules based on presumed lower fluoride intake

– Inappropriate prescriptions for children already receiving adequate fluoride

• Measured by Dean’s Index (mild to severe)

Fluoride Toxicity

• Symptoms of overdose– GI (nausea and vomiting)

– CNS

• Death in 4 hours• Probably toxic dose = 5 mg F/kg• Certainly lethal dose = 16 – 32 mg F/kg (Hodge

and Smith)

15 mg F/kg (Whitford)

Fluoride Toxicity

• Treatment (Augenstein et al)– Determine child’s weight and estimate amount ingested– <8 mg F/kg: give milk, observe > 6 hours, refer if

symptoms develop– >8 mg F/kg: give syrup of ipecac, followed by milk; refer

immediately– Unknown dose: if asymptomatic treat as <8 mg F/kg, if

symptomatic (already vomited) give milk, refer immediately

– Contact poison control center: gastric lavage, IV calcium gluconate

Guidelines for Calculating the Quantity andConcentration of Fluoride

Ion in Fluoride Compounds

Introduction--Why do we calculate the Fluoride Ion?--

• Fluoride by “nature” is a very active element. Its active nature will not allow it to be found in its pure form. As a result, fluoride combines with other elements to form fluoride compounds. We have to calculate the amount of fluoride ion in each compound in order to:

1. Compare the strength of different fluoride compounds by knowing the concentration of fluoride ion in each compound.

2. Calculate the exact amount (“quantity”) of fluoride ion ingested in case of accidental ingestion of any fluoride compound.

--What are the Risks of Ingesting More than the Recommended Dose of Fluoride?--

• In contrast to the desirable anti-cariogenic effect of fluoride, it is also a toxic substance. Acute ingestion of fluoride in large quantities may be followed by rapidly developing signs and symptoms, which may result in death. When it is ingested in relatively small amounts during the period development, it may produce changes in the quality and appearance of enamel (fluorosis). When somewhat larger amounts are ingested over a period of years, changes in the quality and the quantity of the skeleton may occur. This, in fact, is the basis of the use of fluoride ion for the treatment of osteoporosis.

Important Information Before Any Calculation

Percentage “%” means parts per hundred (pph)

Percentage “%” in fluid means gram per 100 ml

1 ounce = 28.4 grams

8 ounces = 227.2 grams

“ppm” means parts per million

ppm = 10,000 x pph “%”

Atomic Weights:

Na = 23

F = 19

Sn = 119

P = 31

O = 16

Example: NaF

23+19 = 42

19/42 = .45 or 45%

Calculation of Fluoride Ion in Fluoride Compounds

• What is the information being requested? Concentration or Quantity of fluoride ion. Follow three simple steps in calculating the fluoride ion in fluoride compounds.

1. Determine the fluoride compound.

You should know the fluoride compound (e.g. NaF), its concentration, and the weight in “milligrams” of that product (only if you are interested in weight). This information can be calculated from the information provided in the product’s label.


2. Calculate the Ratio of Fluoride Ion

This ratio is the key factor for all of the calculations of fluoride. It is the result of the atomic weight of fluoride multiplied by the number of fluoride atoms in the compound divided by the total molecular weight of that compound.

For example: NaF has a ratio of .45 of fluoride ion. This 0.45 is equal to 19/42. “19” is the atomic weight of one fluoride atom. “42” is the molecular weight of the compound.


3. MultiplyMultiply the calculated ratio by the percentage, ppm, or the weight of the fluoride compound to get the percentage, ppm, or the weight of the fluoride ion in that compound.


• Example:

How much F is in 10 ml of Fluorigard mouth rinse?1. Fluorigard has 0.05% NaF (from the label). From the percentage given0.05 gram of NaF per 100 ml

= 50 milligram of NaF per 100 ml= 5 mg of NaF per 10 ml

2. The ratio for NaF is 0.453. Multiply

-If we are interested in concentration of fluoride ion, then we multiply the percentage of the compound (0.05%) by the ratio. 0.05% x 0.45 = 0.0225% fluoride ion (concentration in % pph); To get the ppm, multiply 0.0225 % x 10,000 = 22,500 ppm of fluoride ion in Fluorigard mouth wash

-If we are interested in weight or the quantity (as the example requested), then we multiple the weight of the compound in “mg” by the ratio; 5 mg x 0.45 = 2.25 mg of fluoride in 10 ml of Fluorigard mouth wash

FLUORIDES. What is fluoride? Fluoride is the ionic form of the element fluorine. It is negatively...

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Transcript of FLUORIDES. What is fluoride? Fluoride is the ionic form of the element fluorine. It is negatively...