Transcript Slide 1

FLUORIDES
--Prevention III and IV-Dr. Jeff Johnson
University of Kentucky College of Dentistry
Division of Pediatric Dentistry
Department of Oral Health Science
Enabling Objectives
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discuss the systemic effects of fluoride on the developing dentition.
discuss the topical effects of fluoride related to the dentition, oral soft tissues,
oral microflora, and plaque.
describe the effects of acute toxicity of fluoride as a result of overdoses.
describe the effects of long term, excessive, systemic fluoride exposure.
identify the magnitude of caries preventive effects of both systemic and topical
fluorides.
write prescriptions for systemic fluoride as indicated.
calculate fluoride concentrations.
write a brief narrative describing the history of research on systemic and
topical fluorides.
describe the various formulations of over-the-counter (OTC), and office-based
formulations of fluorides.
discuss the advantages and usage of fluoride varnishes.
describe the antimicrobial/antiplaque effects of fluoride.
discuss the roll of fluoride in remineralization and in its caries preventive
effect.
identify the clinical features of enamel fluorosis.
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
Mechanisms of Action
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Topical
promotes
remineralization
inhibits
demineralization
Mechanisms of Action
• 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.
Mechanisms of Action
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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 fluoriderich environment can create
fluoride-rich, low-carbonate apatite,
which is up to 10X less soluble than
the original apatite structure.
Remineralization
Demineralization
Demineralization
Remineralization
Mechanisms of Action
• Systemic
– improves enamel crystallinity
– reduces acid solubility
– improves tooth morphology (controversial)
Mechanisms of Action
• 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.
Mechanisms of Action
• 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 strep produces 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, “. . .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.
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The first use of adjusted fluoride
levels in water supplies for caries
control began in 1945 and 1946 in
the United States and Canada.
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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.
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Sequential cross-sectional surveys
were conducted over the next 13 to
15 years.
Fluoride
--A Brief Glimpse into History-• 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).
Fluoride
--A Brief Glimpse into History-•
The success of water
fluoridation in preventing and
controlling dental caries led to
the development of fluoridecontaining products, including
toothpaste, mouth rinse, dietary
supplements, and professionally
applied or prescribed gel, foam,
or varnish.
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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.
Fluoride
--A Brief Glimpse into History-• 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
Fluoride
--A Brief Glimpse into History-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.
Fluoride
--A Brief Glimpse into History-• Water fluoridation is cost
effective.
• Fluoride is safe and
effective.
• Per person, it costs on
average 50 cents per year.
• 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.
• 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.
• 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 populations.
*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)
Fluoride
--Other Sources-• Fluorides for Professional Use
– FDA approved for professional use:
• Acidulated phosphate fluoride (APF) with 1.23% (12,300
ppm)
Fluoride
--Other Sources-• Fluorides for Professional Use (continued)
– FDA approved for professional use:
• APF
• Neutral sodium fluoride (NaFl) with 2% (9,000 ppm)
Fluoride
--Other Sources-• 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
--Other Sources-• 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 largest single delivery of fluoride.
– The application stays on tooth surfaces 4 to 6
hours after application (product is purposely
colored to detect presence).
Fluoride
--Other Sources-• Fluoride Varnish (continued)
– The 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 the late 1960s 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
--Other Sources-• 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 “offlabel”!
– 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).
Fluoride
--Other Sources-• Which varnish do we
currently use at
UKCD?
CavityShield
– http://www.omniipharma.com/in
office.htm#cavityshield
Fluoride
--Other Sources-• Cavity Shield
– Red Applicator: 0.40 ml for Mixed and Permanent
Dentition
– Yellow Applicator: 0.25 ml for Primary Dentition
Fluoride
--Other Sources--
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
--Other Sources-• 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
--Other Sources-• 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
--Other Sources-•
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 toothpaste, the salivary level of
fluoride between brushing is thought to be 0.2 to 0.8 ppm
(Duckwork, 1991).
Fluoride and Anticipatory Guidance
for the Pediatric Dental Patient
• Early childhood appointments provide a stage
for discussion of family water use, fluoridevitamin 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).
Fluoride and Anticipatory Guidance
for the Pediatric Dental Patient
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In evaluating daily fluoride
exposures for young children, the
use of filters that may remove
fluoride from city and well water
must be addressed.
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Water testing services exist at the
Kentucky State Department of
Health.
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Most commercial infant water
contains 1 ppm of fluoride.
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Other bottled water brands may
have fluoride concentrations in
varying amounts; the information
should be verified by documentation
requests to the particular bottling
company.
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http://www.bottledwater.org
Fluoride and Anticipatory Guidance
for the Pediatric Dental Patient
• 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 Schedule
Fluoride 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
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3 years – 6 years
0.50 mg/day
0.25 mg/day
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6 years – 16 years
1.00 mg/day
0.50 mg/day
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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
Area
Rx: Sodium fluoride solution (0.125 mg F/drop)
Disp.: 40 mg
Sig.: Before bed time dispense 2 drops of liquid in mouth
• 6-Year-Old Residing in a Fluoride-Deficient
Area
Rx: Sodium fluoride tablets (1 mg F/tablet)
Disp.: 120 tablets
Sig.: Before bed time after a thorough brushing, chew one
tablet, swish, and swallow
Fluoride Supplementation Prescriptions
--Examples--
• High Caries Risk Patient
Rx: NaF Gel (0.5% F)
Disp.: (varies depending on product)
Sig.: Brush on fluoride gel once/twice daily instead of
toothpaste
Example: 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 =
• Certainly lethal dose =
F/kg (Hodge
and Smith)
5 mg F/kg
16 – 32 mg
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
and
Concentration 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)
1 ounce = 28.4 grams
8 ounces = 227.2 grams
Atomic Weights:
Na = 23
F = 19
Sn = 119
P = 31
O = 16
Percentage “%” in fluid
means gram per 100 ml
“ppm” means parts per
million
ppm = 10,000 x pph “%”
Example: NaF
23+19 = 42
19/42 = .45 or 45%
Calculation of Fluoride Ion in Fluoride
Compounds
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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.
Calculation of Fluoride Ion in Fluoride
Compounds
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.
Calculation of Fluoride Ion in Fluoride
Compounds
3. Multiply
Multiply 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.
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Calculation of Fluoride Ion in Fluoride
Compounds
Example:
How much F is in 10 ml of Fluorigard mouth rinse?
1. Fluorigard has 0.05% NaF (from the label). From the percentage
given 0.05 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 0.45
3. 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
QUESTIONS?????