Prof. d-r R.Kabaktchieva
Purpose of fluoride prevention

Purpose of fluoride prevention is to build
resistant tooth structure for better oral health.

Fluoride prevention is aimed at:
- Prevention of dental caries;
- Slowing the progression of dental caries.
Forms of endogenous fluoride
prevantion
Endogenous fluoride prevention is
carried out by using various ways of
supplying fluoride:
- Drinking water fluoridation,
- Use of natural fluoride
mineral water
- Tablets containing fluoride
- Milk fluoridation,
- Salt fluoridattion and others.
Community water fluoridation
(also referred to as fluoridation )

Fluoridation, is defined as the upward
adjustment of the natural fluoride level in
a community's water supply to a level optimal
for dental health.

It is a population-based method of primary
prevention that uses piped water systems to
deliver low doses of fluoride over frequent
intervals.
 Fluoridation
is one of the top ten public
health achievements of the twentieth
century.
 Fluoridation
contributed to a dramatic
decline in dental caries from
the 1950s to the 1980s, and continues to
effectively reduce and prevent tooth decay
today when multiple sources of fluoride,
such as fluoride toothpaste, are readily
available.

Continued monitoring of fluoride exposure
from all sources, especially from sources
such as fluoride-containing dentifrices, is
important to achieve the appropriate balance
between maximum caries-preventive benefit
and minimal risk of fluorosis.

Fluoridation has been shown to be an
effective intervention and sound public policy.
The American
Dental
Association (ADA) officially
defines water fluoridation as
the adjustment of the natural
fluoride concentration of
fluoride-deficient water
supplies to the recommended
level for optimal dental health.
The
optimal fluoridation level
varies by geographical location
according to the temperature
and is a value that ranges from
0.7 ppm F to 1.2 ppm F.

Parts per million (ppm) and milligrams/liter
(mg/l) are essentially equivalent, and the
terms are used interchangeably.

One part per million is the same
concentration as 1 mg/l.

Some documents refer to concentrations used
in water fluoridation as parts per million;
others use milligrams per liter.
 Fluoride
is the thirteenth most abundant
element on Earth.
 This
naturally occurring substance is found
in water, soil, plants, and, even in air.
 Certain
foods, such as tea and fish,
contain significant amounts of fluoride.
 The
World Health Organization (WHO)
identify fluoride as a nutrient important
for health.
 Fluoridation
can be thought as a form of
nutritional supplementation in which
fluoride is added to the drinking water.






Fluoridation is an ideal public health
intervention because it :
(1) benefits people of all ages;
(2) is socially equitable and does not exclude
any group;
(3) imparts continuous protection with no
compliance or conscious effort required by
consumers, other than drinking optimally
fluoridated water;
(4) works without requiring individuals to access
care
(5) does not require the costly services of health
professionals;
(8) is remarkably cost effective.
Mechanisms of Action of Fluoride
Fluoride works in 3 ways to reduce
and prevent tooth decay
(1) systemically, by being ingested and
incorporated into the enamel structure during
tooth development;
 (2) topically, by promoting remineralization
and inhibiting demineralization of tooth
surfaces after eruption;
 (3) topically, by inhibiting glycolysis in
microorganisms, thereby hindering the ability
of bacteria to metabolize carbohydrates and
produce acid.

 The
greatest effect on reducing and
preventing decay is topical;
 however,
both systemic and topical
mechanisms are important.
 Systemic
fluoride is ingested, or taken
into the body during consumption of
foods or beverages.
 Systemic
fluoride can be incorporated
directly into the hydroxyapatite crystalline
structure of the developing tooth,
the smaller fluoride ions replacing hydroxyl ions in
the crystalline structure of the tooth and producing a
less-soluble apatite crystal.
 Today
it is accepted that the systemic
effect on caries prevention is the lesser
effect;
 however,
there is current evidence that
systemic exposure to fluoride during tooth
formation reduces tooth decay.

Topical fluoride concentrates in the plaque
and saliva, thereby enabling it to come into
frequent contact with the surfaces of the teeth.

Its effects are posteruptive and can benefit
people of all ages .

The decay process involves both
demineralization and remineralizaiton and can
move in either direction.
Cycles of demineralization and
remineralization continue
throughout the lifetime of the tooth

Fluoride, especially that held in plaque, is an
essential nutrient in the remineralization of teeth.

Cariogenic bacteria residing in dental plaque
metabolize sugars and other carbohydrates,
producing acid that begins to dissolve, or
demineralize, the tooth's enamel crystal surface.

Calcium, phosphate, and carbonate are lost
from the enamel and can be captured in the
adjacent plaque.

The lowered pH caused by the acid also releases
fluoride contained in the plaque.

Then the fluoride from the plaque and available
saliva are taken up by the demineralized enamel
along with calcium, phospate, and carbonate;

Тhis results in remineralization as the ions reform into an improved enamel crystal structure
that contains more fluoride and less carbonate,
and is more resistant to acid

Fluoride also inhibits the process that bacteria
use to metabolize carbohydrates, thus reducing
bacterial acid production and reducing
dissolution of tooth enamel.
Therefore,
on a regular basis,
water fluoridation replenishes
small quantities of fluoride to
the plaque and saliva, which
contributes to good oral
health.

Systemic fluorides also provide a topical
effect because saliva contains some
fluoride from ingestion, is continually
available at the tooth surface, and becomes
concentrated in dental plaque where it
inhibits acid-producing cariogenic bacteria
from demineralizing tooth enamel.

Fluoride concentration in the plaque is
50 to 100 times higher than in the whole
saliva.
In summary
Fluoridation has been found to
reduce dental decay through three
mechanisms:
 (1) by systemic ingestion of fluoride,
which is incorporated into the
developing tooth structure and
converts hydroxyapatite into
fluorapatite,
thus reducing the solubility of
tooth enamel in acid and making
it more resistant to decay;
 (2) by topical action of fluoride in the
plaque and saliva, which enhances
remineralization of tooth enamel that has
been demineralized by acids produced by
decay-causing bacteria,
 (3)
by topical interaction with bacteria in
the plaque, which reduce the acid
production by dental-plaque organisms.
Enamel Fluorosis
Fluoridation has risks as well as benefits.
 Fluoride in water can cause a dental condition
known as enamel fluorosis or fluorosis.


The mild and very mild forms of fluorosis may
be so minimally apparent that individuals may
not even realize that their teeth are affected,

The moderate and severe forms of fluorosis
result in stained and pitted teeth that are
cosmetically objectionable.
 Fluoridation
involves finding
the appropriate balance between
the benefits of caries prevention
and improved oral health,
and the potential for cosmetic
conditions associated with very
mild and mild fluorosis.
 Enamel
fluorosis results from
hypomineralization in enamel surfaces
of teeth that have been exposed to fluoride
ingested during enamel formation.
 Enamel
fluorosis can present in a number
of ways, from white striae to the most
severe form that could be classified as a
developmental defect of the enamel.

The degree of fluorosis depends on the total
dose of fluoride from all sources, as well as on
the timing and duration of fluoride exposure.

Enamel fluorosis occurs in children who
consume fluoride when their teeth are
developing;

Fluorosis cannot occur once enamel formation
is complete and the teeth have erupted,
regardless of intake; therefore, older children
and adults are not at risk for enamel fluorosis.
 Standard
of 2.0 ppm F was set to
protect children from
moderate/severe enamel fluorosis.

Questionable, very mild, and mild stages of
fluorosis often result from very young children
swallowing too much fluoride-containing
toothpaste or from inappropriate supplementation
with prescription fluoride products such as

(1) physicians or dentists independently
prescribing fluoride supplements;

(2) physicians or dentists prescribing fluoride
supplements without checking the fluoride
content of the child's water supply.

In either case, a child gets a "double" dose of
fluoride on a daily basis.

Monitoring total fluoride intake is
complicated, considering the availability of
multiple sources of fluoride.

Also, fluoride from tablets/drops is
ingested and absorbed at one time of day,
as opposed to fluoride in water in which the
ingestion and absorption of low-dose
fluoride is distributed throughout the day.

These factors have been considered in the
establishment of fluoride dosage schedules,
which were adjusted downward in the 1990s,
particularly for children in the first 6 months of
life.

The Dietary Fluoride Supplement Schedule
approved by the American Dental Association,
the American Academy of Pediatrics, and the
American Academy of Pediatric Dentistry should
be followed when fluoride supplements are
prescribed
Dietary Fluoride Supplement Schedule, 1994
Fluoride Ion Level in Drinking Water (ppm)a
Age
<0.3 ppm F
0.3-0.6 ppm F
None
None
None
6 months-3
years
0.25 mg/dayb
None
None
3-6 years
0.50 mg/day
0.25 mg/day
None
6-16 years
1.0 mg/day
0.50 mg/day
None
Birth-6
months
a
b
>0.6 ppm F
a-1.0 part per million (ppm) = 1 milligram/liter (mg/l)
b-2.2 mg sodium fluoride contains 1 mg fluoride ion.
SSource: Meskin, 1995105; American Academy of Pediatrics Committee on Nutrition,
1995106; and American Academy of Pediatric Dentistry, 1995107.
Recommendations to reduce
the risk for enamel fluorosis.

All persons should know whether the fluoride
concentration in their primary source of drinking water is:
- below optimal (less than 0.7 ppm F),
- optimal (0.7-1.2 ppm F),
- above optimal (greater than 1.2 ppm F).
This knowledge is the basis for all individual and
professional decisions regarding use of other fluoride
modalities
(e.g., fluoride toothpaste, mouthrinses, or supplements).

The risk of developing very mild fluorosis versus
the benefit of decreased dental caries and
attendant treatment costs should be
communicated to patients who express concern.

Severe fluorosis does not occur from fluoridated
water alone, and most frequently occurs when
there is too much naturally occurring fluoride in
water.
Optimal Fluoride Levels
Тhe higher the average temperature in a
community, the lower the recommended water
fluoride level. For every geographic location in the
United States, a specific optimal fluoride
concentration is recommended for the drinking
supply, with optimal levels ranging from 0.7 to 1.2
ppm F
 In addition, optimal fluoride concentrations were
recommended at a time before there were other
regular sources of fluoride exposure, such as
discretionary fluoride toothpaste, mouthrinses, or
dietary supplements.

Other Fluoride Vehicles
Salt
fluoridation results in small
amounts of fluoride being released from
plasma throughout the day.

To achieve dental-caries reductions at levels
comparable to water fluoridation, the level of
fluoride supplementation of refined salt should
be at least 200 mg F/kg as sodium fluoride or
potassium fluoride.
 Salt
fluoridation requires centralized
salt production, as well as
monitoring.
 Countries
using salt fluoridation
include Switzerland, France, Costa
Rica, Jamaica, Germany, Mexico,
Colombia, Ecuador, Venezuela, and
Uraguay
Milk fluoridation
 The
addition of 5 mg of fluoride to 1 liter of
milk,
has been introduced as a vehicle of school-based fluoride
delivery in some countries (Bulgaria, Chile, China, the Russian
Federation, and the United Kingdom).

Additional studies are required to adequately assess milk
fluoridation as a viable caries-prevention strategy.

According to the WHO report, "The distribution of fluoridated
milk can be more complicated than that of fluoride
supplements (tablets or drops).“
Fluoride mouthrinses

School-based weekly fluoride rinse programs,
use 0.2% sodium fluoride in preventing coronal
caries in school children who are at risk for
dental caries.

The National Preventive Dentistry Demonstration
Project examined preventive efforts from 19761981 in ten cities in the United States and
reported
fluoride mouthrinse programs had little effect in
reducing caries, especially among children from
fluoridated communities.
END