10. Fluoride 2 - Fresh Men Dentists

Preventive Dentistry
(Lecture 10)
Other caries preventive factors
Dr Caroline Mohamed
D Caroline Mohamed
Outline of lectures
Topically applied fluoride
Systemically administered fluoride
Fluorides agents and compounds for topical use
Delivery systems for topical self-application of fluoride
Other oral hygiene aids
Delivery systems for professional topical application of
D Caroline Mohamed
Topical Applied Fluoride
• The posteruptive cariostatic effects of fluoride are
correlated with :
– fluoride concentration as well as with
– total exposure time.
The latter is also influenced by the "substantivity" of
fluoride in the oral cavity.
D Caroline Mohamed
• Fluoride clearance fases.
• First within 1 hour.
• The analysis of saliva after a single application of a fluoride
dentifrice or mouthwash shows that much of the retained fluoride
is cleared from the mouth within 1 hour.
• Secondary clearance phase of 2 hours or more.
• The salivary fluoride concentration decreases more slowly.
• The initial rapid clearance phase is the result of salivary washout
release into saliva
of fluoride initially retained in oral reservoirs.
and the second phase is initiated by the
(Duckworth et al, 1991, 1994)
D Caroline Mohamed
Potential reservoirs are:
– the teeth,
– the plaque,
– the soft tissues of the
– the tongue,
– the cheeks, and
– stagnation zones between
the teeth, under the
tongue, and in the buccal
D Caroline Mohamed
• From a cariostatic aspect, the most important
fluoride reservoirs are:
– CaF2 and
– fluoride bound to plaque bacteria.
D Caroline Mohamed
• The most important effects of posteruptive (topical) use of
fluoride are:
– the inhibition of demineralization and
– enhancement of remineralization.
• Fluoride exerts physiochemical effects in:
– the oral fluids, such as the interrod and intercrystalline
fluid, pellicle fluid, plaque fluid, and saliva,
– bound in CaF2, FA, and FHA (fluorohydroxyapatite).
D Caroline Mohamed
Fluoride also:
• reduces acid formation in the dental plaque,
• may reduce plaque formation rate and plaque adhesion,
• may change the ecology of the plaque microflora.
Of these effects, the most important is the reduction of acid
D Caroline Mohamed
• The fall in plaque pH following sucrose exposure is reduced when
plaque fluoride content has been enhanced by repeated topical
• Fluoride alone is inadequate to completely arrest caries process
because its cariostatic effect is limited.
• If plaque pH falls below about 4.5 , the plaque fluid becomes
demineralization will occur, regardless of the presence of
D Caroline Mohamed
Systemically administered fluoride
• The cariostatic effect of fluoride is almost 100%
posteruptive (topical effect).
• Fluoride has been systemically administered in:
drinking water,
chewing gums,
D Caroline Mohamed
• Different concentrations of sodium fluoride have been used
in these delivery systems.
• Fluoridated drinking water is the most cost-effective public
health measure for prevention and control of caries and
remineralization of early enamel caries.
• This is due to the fact that most people drink water several
times a day with even those without regular dental care and
regular use of fluoride toothpaste benefit from water
D Caroline Mohamed
• Water fluoridation should therefore be recommended in all
populations in which there is a relatively high caries prevalence,
poor oral hygiene, and a lack of organized preventive programs or
daily use of fluoride toothpaste.
• The recommended fluoride concentration in temperate climates,
is 0.7 to 1.2 mg of F/L, but in warm to hot subtropical and tropical
regions, only 0.5 to 0.7 mg of F/L is recommended, to prevent the
development of esthetically unacceptable fluorosis.
D Caroline Mohamed
• Results from early studies with fluoridated water
showed about 50% caries reduction in the permanent
dentition and 40% in the primary dentition, compared to
control areas. Significant reductions in root caries were also
seen (Murray et al 1991).
• At that time, caries prevalence was high in the United States
and in Europe, where the studies were run, and few topical
agents such as toothpaste and mouthrinses were available.
D Caroline Mohamed
• Nowadays, the supplementary effect of fluoridated
drinking water would be only 5% to 25% in most European
countries and the USA, because of improved oral hygiene
and daily use of fluoride toothpaste and other topical
fluoride agents, which have resulted in very significant
reductions in both caries prevalence and incidence.
• However, in regions with relatively high
caries prevalence, limited dental resources,
and no daily use of fluoride toothpaste,
water fluoridation should still achieve about
50% caries reduction.
D Caroline Mohamed
• However, only about 3% of the world population has access to
fluoridated drinking water, mostly in the USA, where caries
prevalence is low and almost 100% of the population use
fluoride toothpaste and other topical fluoride agents daily.
• The use of the other fluoride delivery systems in the world is
marginal (salt, 0.6%; tablets, etc 0.3%).
D Caroline Mohamed
Prevalence of dental fluorosis
• an increase in the prevalence of dental fluorosis has
been noticed.
• The increase is in the mild and very mild forms of
fluorosis, and is proportionally greater in nonfluoridated areas than in fluoridated areas.
• This is because of the increase in the mean fluoride
intake from all sources since the 1940s.
Some of the reasons that were postulated for
the increase in the prevalence of fluorosis
• widespread use of fluoride in both
• Foods and beverages may be processed in
fluoridated communities but are shipped,
sold, and consumed in non-fluoridated
• Hallo effect
Worldwide distribution
Endemic in 22 countries
in Asia, India and China are worst affected
Mexico in North and Argentina in Latin America
East and North Africa are also endemic
Risk factors
• The most important risk factor in determining
fluorosis occurrence and severity is the total
amount of fluoride consumed from all sources
during the critical period of tooth development.
• Demographic risk factors:
• Age: fluorosis is related to the ingestion of F
during critical period of tooth development.
• SES : fluoride intake from tooth paste and infant
formula can vary by SES status
Optimal levels of fluoride
drinking water
• It was accepted that optimal level of fluoride in
drinking water was 1PPM.
• With other sources of fluoride now days this level
become 0.5 to 1 ppm according to the community.
• Waters with high levels of fluoride content are
mostly found at the foot of high mountains and in
areas where the sea has made geological deposits.
• Known fluoride belts on land include:
• one that stretches from Syria through Jordan,
Egypt, Libya, Algeria, Sudan and Kenya,
• and another that stretches from Turkey
through Iraq, Iran, Afghanistan, India,
northern Thailand and China.
• There are similar belts in the Americas and
Japan. In these areas fluorosis has been
Fluoride dietary supplement
• Was used in non
fluoridated areas
• There is strong evidence
that fluoride
supplements are risk
factor to mild to
moderate fluorosis.
• The risk is high in
fluoridated areas.
Early use of fluoride tooth paste
• Young children in whom
the swallowing reflex is
not fully developed can
ingest up to 0.3 –o,5mg
F at each brushing.
• The risk is not as high as
fluoride supplement
• Infant formula: B/C its own F content and especially
because it is mixed with fluoridated water.
• Other factors that have been associated with
susceptibility of populations to dental fluorosis are
Dietary supplements
• Fluoride dietary supplements were first introduced in the
late 40´s and were intended as a substitute for fluoridated
water for children in non-fluoridated areas.
• Supplements contain fluoride from 0.25 , 0.5 to 1.0 mg
usually as sodium fluoride or calcium fluoride, acidulated
phosphate fluoride or potassium fluoride.
• The original pills have been joined by chewable tablets and
D Caroline Mohamed
• Animals experiments shown that fluoride given once a day is
more likely to cause fluoroses than the same ammount of
fluoride given intermittently.
• In Europe, it is recommended that a dose of 0.5 mg F/day
should be prescribed only to children living in areas
with water supplies containing less than 0.3 ppm F,
who are considered to be high risk, after a diet
analyses, starting only at age of 3 years.
D Caroline Mohamed
American Dental Association. Fluoride and fluoridation. Available at:
www.ada.org/public/topics/fluoride. Accessed June 20, 2007.
D Caroline Mohamed
• The aim of using fluoride tablets is to achieve a supplementary
posteruptive cariostatic effect similar to that provided by other
topical fluoride agents, such as toothpaste.
• Therefore, slow release lozenges should be recommended
because of the prolonged fluoride clearance time in the oral
• An optimal effect should be achieved if the lozenges are used as a
"dessert" directly after meals, particularly in adults with reduced
salivary secretion rates.
D Caroline Mohamed
• For very caries-susceptible patients fluoride chewing
gum should be the preferred systemic agent, to be
used for 15 minutes directly after every meal.
It is recommended primarily for caries-susceptible adults
with reduced salivary secretion rates and for cariessusceptible children and young adults, especially during the
eruption of molars (5.5 to 7 years and 11.5 to 13 years).
D Caroline Mohamed
Fluoride agents and compounds for topical use
• The caries-preventive effect of most topical fluoride
measures to range between 20% and 40%.
• Topical fluoride agents are available for selfcare or
professional application (eg, by dentists, dental hygienist or
dental assistant).
• For selfcare, the fluoride agents can be used: toothpastes;
toothpicks, dental tape, and dental floss; mouthrinses; gels,
artificial saliva, lozenges, and chewing gum.
• Professionally applied fluoride agents are paints; gels;
prophylaxis pastes; varnish, glass-ionomer cement (GC), and
other slow release agents.
D Caroline Mohamed
The cariostatic effect of fluoride toothpastes was
recognized more than 40 years ago.
More than 90% of toothpastes in the industrialized
countries contain fluoride (WHO 1994).
D Caroline Mohamed
• Fluoride toothpaste is by far the most frequently used topical
fluoride agent, used by 450 million people (WHO 1994).
• Only 20 million people use mouthrinses or tablets, while 20
million receive professional applications of fluoride (WHO
D Caroline Mohamed
The main functions of toothpastes are to
facilitate mechanical plaque removal by
brushing and to serve as vehicles for active
agents (fluorides, chemical plaque control
agents, anticalculus agents, etc.).
D Caroline Mohamed
D Caroline Mohamed
The use of fluoride
dentifrices has reduced the
incidence of caries by 9.7%–
Sodium fluoride (NaF) and
e (MFP) are the most
common sources of fluoride
in dentifrices
– These can be used alone
or in combination
1. Twetman S, et al. Acta Odontologica Scandinavica 2003;61;6:347-355.
2. Volpe AR, et al. Am J Dent. 1993;6:S13-S42.
3. Sullivan RJ, et al. J Clin Dent. 1995;6:135-138.
Fluoride formulation factors
and mode of action
Not all fluoride toothpastes are
the same
– Different fluoride source,
pH and choice of
formulation can affect
fluoride uptake1,2
Fluoride needs to be deposited
and slowly released to be
effective following brushing3
– The amount of fluoride
released into saliva and
adsorbed by enamel
during the period after
is critical
1. Friberger P. Scand J Dent Res 1975:83;339-344.
2. White DJ, et al. Caries Res 1986;20:332-336.
3. ten Cate JM. Eur J Oral Sci 1997;105:461-465.
Many different fluoride compounds are used in agents
for self-care and professional application. The three
main categories are:
1. Inorganic compounds, including NaF, stannous fluoride
(SnF2), ammonium fluoride (NH4F) etc.
The salts are readily soluble, providing free fluoride.
2. Monofluorophosphate-containing compounds, such as
sodium monofluorophosphate (Na2FPO4): The fluoride is
covalently bound in the FPO32- ion and apparently requires
hydrolysis to free the F-.
3. Organic fluorides,such as amine fluoride, and silane
D Caroline Mohamed
Ionic compounds
D Caroline Mohamed
Factors that influence fluoride delivery
Fluoride source (NaF, MFP, stannous fluoride)
– For example, MFP requires activation by
hydrolysis by salivary phosphatase to release
active F-
Fluoride concentration in formulation
Formulation properties
– pH will drive different fluoride modes of action
– Ingredients such as divalent cations (eg, Ca2+)
can reduce the amount of available fluoride
– Ingredients such as high levels of phosphates
can reduce fluoride uptake
Sometimes two or more of the above compounds are
combined in the same topical fluoride agent.
The fluoride concentration in agents for self-care, such as
toothpastes and mouthrinses, varies from 0.012% to 0.15%
fluoride, while up to 1 % fluoride is used in gels.
The fluoride concentration in agents for professional
application is usually much higher, ranging from about 0.7%
to 6.0%, which, as discussed earlier, will promote
precipitation of CaF2 reservoirs.
D Caroline Mohamed
Fluorides mouthwashes
• Stannous Fluoride- antiplaque properties
• Sodium Fluoride
• The stannous ion, not the fluoride, which is
responsible for antimicrobial effect.
• Mechanism of action:
Tin from the stannous ion enters the cell, impairs
the metabolism and effect the growth and
adherence properties of bacteria. Week
antiplaque activity .
D Caroline Mohamed
Delivery systems for topical
self-application of fluorides
The following topical fluoride agents are available for
dental floss, and dental tape;
mouth rinses;
artificial saliva;
lozenges; and
chewing gum.
D Caroline Mohamed
The following fluoride compounds are used in
l. Inorganic fluorides
Sodium fluoride (NaF)
Sodium monofluorophosphate (Na2FPO3)
Stannous fluoride (SnF2)
Potassium fluoride (KF)
Aluminum fluoride (AlF3)
D Caroline Mohamed
2. Organic fluorides
a. Amine fluoride (Hetaflur)
b. Amine fluoride (Olaflur)
3. Combinations of fluorides
a. Sodium fluoride + sodium
b. Amine fluoride + Stannous fluoride
c. Amine fluoride + Sodium fluoride
D Caroline Mohamed
• Sodium fluoride and sodium monofluorophosphate
are by far the most common, followed by stannous
fluoride and amine fluoride.
• Almost all the NaF, SnF2, and amine fluoride in
toothpastes will be dissolved in the mouth during
brushing, releasing optimal amounts of free Fions.
• On the other hand Na2 FPO3 initially releases fewer
free F- ions, but also supplies FPO32- ions which
within about 1 hour are broken by phosphate
enzymes in the mouth, releasing F- ions.
D Caroline Mohamed
• From 1955 to 1985 the standard fluoride
concentration in toothpastes was about 1,000
ppm of fluoride (0.1% F=1 mg F/g toothpaste),
supplied as 0.2% Na F, 0.76% Na2FPO3, SMFP
and 0.4% SnF2.
• The average caries reduction achieved in
various 2- to 3-year clinical studies was about
25% to 30% (Johnson,1993; Volpe et al, 1993).
D Caroline Mohamed
• The cariostatic elfects of fluoride toothpastes are also
related to accessibility and fluoride clearance in the oral
• Accessibility may be improved by:
1. Frequent mechanical removal of dental plaque,
particularly on the approximal surfaces of the posterior
2. Deliberate application of fluoride toothpaste to the
posterior interdental spaces before approximal
3. Thorough swishing with the remaining toothpaste
slurry after cleaning, followed only by one brief rinse
with water.
D Caroline Mohamed
The following measures may prolong fluoride
clearance time from the oral fluids:
Using as high a fluoride concentration as possible.
Increasing the daily frequency of fluoride toothpaste.
Using the toothpaste technique recommended above.
Filling the posterior interdental spaces with fluoride
toothpaste after cleaning at bedtime.
D Caroline Mohamed
• Toothpastes containing fluoride as well as chemical plaque
control agents should be recommended, particularly to
caries-susceptible patients with high plaque formation rates
(Plaque Formation Rate Index score 4 to 5, periodontitis, or
gingivitis. )
Toothpastes containing SnF2 or amine fluoride
also have documented antiplaque effects.
D Caroline Mohamed
Other oral hygiene aids
• Oral hygiene aids that not only mechanically remove plaque but
also at the same time, release fluoride to the most caries
susceptible tooth surfaces in the dentition, the approximal
surfaces of the posterior teeth, would be most appropriate.
• Several brands of fluoridated toothpicks (TePe, Butler, Elmex,
Jordan, etc) and dental tape and floss (Johnson & Johnson, OralB, Butler, Elmex,Jordan, etc) have been introduced
D Caroline Mohamed
Weekly school-based mouthrinsing with 10-mL neutral 0.2% NaF
solutions for 1 minute are still very cost effective for caries control
in regions where water fluoride concentration is low, for
populations with high prevalence of caries, poor oral hygiene and
no daily use of fluoride toothpaste.
D Caroline Mohamed
• Rinsing with 10 ml of fluoride solution (0.025% F) for 1 minute
after every tooth cleaning procedure is an efficient
supplement for caries control in caries-susceptible patients.
• Fluoride mouthrinses containing chemical plaque control
agents (triclosan + copolymer+ sodium lauryl sulfate [Colgate
Total], chlorhexidine, amine fluoride + SnF2 [Meridol], etc)
should have a greater cariostatic effect than pure neutral NaF
D Caroline Mohamed
Artificial saliva
For patients with dry mouth (xerostomia), artificial saliva
containing NaF is available to improve physical and subjective
symptoms and reduce the risk of rampant caries in these
extremely high-risk patients.
However, in these patients, meticulous mechanical and chemical
plaque control and combination of the most efficient fluoride
agents are also essential.
Fluoridated artificial spray is formulated either as a gel or as a
spray; patient acceptance is generally higher for the spray,
which is usually applied 20 to 30 times a day.
D Caroline Mohamed
D Caroline Mohamed
The effect of fluoride gels is related to the concentration, time
of application, accessibility, and other factors.
Most commercial fluoride gels for daily use by self-care contain
about 0.5% fluoride in the form of neutral NaF, acidulated
phosphate fluoride, SnF2 or amine fluoride plus NaF. The last
two also have documented anti plaque effects.
D Caroline Mohamed
• To improve the effect of the gels, the
recommended application time is 4 minutes or
more preferably applied in customized trays.
D Caroline Mohamed
Delivery systems for professional topical
application of fluorides
The following systems are available for professional application:
• fluoride solutions for painting gels,
• prophylaxis pastes, and
• slow-release agents, such as varnishes and glass-ionomer
The fluoride concentration in agents for professional use ranges
from 1% to 8%.
D Caroline Mohamed
The fluoride compounds most commonly used
professionally are neutral NaF, acidulated
phoshate fluoride,and SnF2 .
Amine fluoride and silane fluoride are also in
some commercial products.
For optimal accessibility, plaque must be
removed by professional mechanical tooth
cleaning before the fluoride agent is applied
to the tooth surfaces at greatest risk.
D Caroline Mohamed
Professionally applied fluoride agents
recommended for public health programs for.
1. for areas with relatively homogenous high-risk
prevalence, fluoride-deficient drinking water and lack
of fluoride toothpaste, but personnel resources
available for a school-based preventive program;
2. in special risk groups such as the mentally
handicapped or elderly people with reduced salivary
flow, exposed root surfaces and heavily restored
dentitions; and in people with senile dementia.
D Caroline Mohamed
professionally applied fluoride agents are
also justified as a public health measure for
specific groups of children, during eruption
of the first and second molars (5 to 7 year
olds and 11 to 13 year olds).
D Caroline Mohamed
Fluoride solutions for painting
The most common fluoride solutions for
painting are neutral 2% NaF (1% F), 8% SnF2
(2% F) and acidulated phosphate fluoride
(1.23% F).
D Caroline Mohamed
Fluoride gels
Fluoride gels for professional use contain a similar
assortment of fluoride compounds as gels for self-care
(neutral NaF, acidulated phosphate fluoride, SnF2,
amine fluoride plus NaF).
For optimal accessibility, plaque must he removed by
professionally by mechanical tooth cleaning, the gel
syringed into the posterior interproximal spaces,
followed by gel application in a customized tray for
more than 4 minutes.
D Caroline Mohamed
Fluoride gel in disposable trays
D Caroline Mohamed
Prophylaxis pastes
• They are used mainly for professional
mechanical tooth cleaning but also for
finishing and polishing and may contain
D Caroline Mohamed
Semislow-release and slow-release fluoride
• These are such as fluoride varnishes, glassionomer
• Examples of fluoride varnishes are:
Duraphat (5% NaF; 2.3% F), Fluor Protector (silan
fluoride; 0.1% F) and Bifluorid 12 (6% NaF + 6% CaF2;
about 6% F).
Based on clinical studies, the caries reduction achieved
by fluoride varnishes ranges from 20% to 70%.
D Caroline Mohamed
Fluoride varnish
D Caroline Mohamed
• It is recommended that the initial varnish application be
repeated 3 times within 7-10 days in patients with caries
risk, to heal gingivitis, thereby reducing the plaque formation
rate, and to arrest enamel caries by sealing the outer
micropore surface as soon as possible.
• Thereafter the varnish should be reapplied at needs related
intervals, 2-4 times/year.
D Caroline Mohamed
• Detail the techniques for fluoride gel
application and fluoride varnish application
and their indications.
D Caroline Mohamed
It is not fun!
D Caroline Mohamed
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