What is Fluoride?
• Fluoride is the ionic form of the element
• Fluoride is a mineral found throughout the
earth's crust and widely distributed in nature.
• Found in soils rich in fluorspar,cryolite,and
Rich amounts:sea foods and tea leaves.
Chief Source of Flouride.
• Topical agents (toothpaste).
According to WHO
• Flouridated Salt / Milk
Distribution of Flourides.
• Teeth and skeleton have the highest concentrations
--Due to the affinity of fluoride to calcium.
• Fluoride content of teeth increases rapidly during
early mineralization periods and continues to
increase with age,but at as lower rate.
Use of Flouride.
• Fluoride helps to prevent cavities.
Summary of Anti-Caries Activity of
• Fluoride prevents demineralization.
• Fluoride enhances remineralization.
• Fluoride alters the action of plaque bacteria.
• Fluoride aids in posteruptive maturation of
• Fluoride reduces enamel solubility.
Fluoride prevents demineralization.
• Formation of fluorohydroxyapatite (FAP).
• Inhibition of mineral loss from enamel.
Fluoride enhances remineralization.
• formation of a fluoride reservoir.
• creation of supersaturated solutions.
Fluoride alters the action of plaque
At low pH, fluoride combines with hydrogen
ions and diffuses into oral bacteria as
hydrogen fluoride (HF)
Inside the cell HF dissociates, acidifying the
cell and releasing fluoride ions
Fluoride ions inhibit glycolysis
As fluoride is trapped inside the cell this
becomes a cumulative process
Prevention of cavities by Flouride.
Two different ways:
• Fluoride concentrates in the growing bones
and developing teeth of children, helping to
harden the enamel on baby and adult teeth
before they emerge.
• Fluoride helps to harden the enamel on adult
teeth that have already emerged.
Application Types of Flourides.
• Topically (On the surface).
• Systematically (Throughout the body).
Definition: The term “topically applied fluorides” is used
to describe those delivery systems which provide fluoride
for a local chemical reaction to the exposed surfaces of
1.Caries active individuals
2.Children shortly after periods of tooth eruption,
especially those who aren’t caries free.
3.Those who take medication that reduce salivary flow or
4.Post periodontal surgery when roots are exposed.
Topical Fluorides products can be divided
into two broad categories:-
Professionally Applied Fluorides Product
Self Applied Fluorides Products
Professionally applied topical fluorides:
It was introduced by Bibby in 1942.
Involve the use of high fluoride concentration products
ranging from 5000-19,000ppm, which is equivalent to 5-
Self applied products:
Include fluoride dentifrices, mouth rinses & gels
Are low fluoride concentration products ranging from
200-1000ppm or 0.2-1 mgF/ml.
Topical fluorides are divided into two categories:
• Toothpaste :- Brushing.
• Mouth Rinses :- Gargling.
• Foams :- Professionally used & are put into a
• Gels :- Can be painted on or applied via a mouth
Aqueous solutions & gels
The gel adheres to teeth &
eliminates the continuous wetting
of enamel surfaces required
when solutions are used.
Thixotropic solutions are not
gels, but have a high viscosity
under storage conditions &
become fluid under conditions of
If prophylaxis pastes
containing fluoride are used,
the lost fluoride is
replenished & there is a
significant gain in the
concentration of fluoride.
Developed to minimize the risk of fluoride over dosage
as well as to maintain the efficacy of topical fluoride
Its lighter than a conventional gel & therefore only a
small amount of agent is needed for topical application
The surfactant has cleansing action by lowering surface
tension, this facilitates the penetration of material into
It doesn’t require suctioning so it offers advantages for
Increasing the time of contact between enamel surface & Topical
fluoride agents favors the deposition of fluorapatite &
It s a viscous yellow material, containing 22,600 ppm fluoride as
sodium fluoride in a neutral colophonium base.
Its a clear polyurethane based product containing 7000 ppm
fluoride from difluorosilane.
Its dispensed in iml ampules each ampule containing 6.21mgof
It has low fluoride concentration than duraphat & has equal efficacy to
that of duraphat as caries preventive agent.
• Important component of toothpaste
• Protects the tooth by making the enamel
• Toothpastes are classified as drugs, not
• Level of fluoride must be carefully controlled
and measured accurately.
• Introduced around the world in the mid
Protection by Saliva.
• After you eat, your Saliva contains acids that
• At other times when your saliva is less acidic it
does just the opposite, replenishing the
calcium and phosphorous that keep your
teeth hard. This process is caused
Helps to Prevent.
• Cavities by strengthening the surface of the
teeth (the enamel).
• Reducing the ability of bacteria contained in
dental plaque to produce acid.
• Re-mineralizing existing dental cavities.
Fluoride can actually heal small cavities in some cases, and prevent the need for dental
Topically fluoride application by a Dentist , Dental Hygienist or any
other Dental Auxiliary has become an established Caries-Preventive
Procedure in the Dental History. The three agents currently used as
professionally applied fluorides are:-
1. Neutral Sodium Fluoride (NaF)
2. Acidulated Phosphate Fluoride (APF)
3. Stannous Fluoride (SnF2)
The fluoride may be used in an aqueous solution, a viscous gel, a
prophylactic paste or as a dental varnish and can be applied using the
Paint on Technique or the Tray Technique.
TOPICAL FLUORIDES USED IN PREVENTIVE
3.ACIDULATED PHOSPHATE FLUORIDE
NEUTRAL SODIUM FLUORIDE
A minimum of four applications with a 2% sodium fluoride
solution gives a caries reduction of 30%.
METHOD OF PREPARATION:
It is prepared by dissolving 20 gms of NaF powder in 1L of
distilled water in a plastic bottle
At the initial appointment teeth are cleaned with pumice slurry &
then isolated with cotton rolls & dried with compressed air.
Using cotton-tipped applicator sticks ,the 2% NaF is painted on
air dried teeth so that all tooth surfaces are visibly wet. The
solution is allowed to dry for 3-4 min.
This procedure is repeated for each of the isolated segments
until all the teeth are treated.
A 2nd, 3rd and 4th fluoride application, each not preceded by a
prophylaxis, is scheduled at intervals of approximately one week;
The four-visit procedure is recommended for ages 3, 7, 11 and 13
years, coinciding with the eruption of different groups of primary
and permanent teeth.
Advantages of neutral sodium fluoride solution :
It is relatively stable when kept in a plastic container;
The taste is well accepted by patients;
The solution is non-irritating to the gingiva;
It does not cause discoloration of tooth structure;
The series of treatments must be repeated only 4 times in the
general age range of 3 to 13, rather than at annual or semiannual
Disadvantage of neutral sodium fluoride solution :
The major disadvantage of the use of sodium fluoride is that the patient
must make 4 visits to the dentist within a relatively short period of
STANNOUS FLUORIDE : (SnF2) :
Stannous fluoride has been used at 8% and 10% concentrations
Method of preparation of stannous fluoride solution :
Solutions of stannous fluoride are not stable. Soon after mixing
they become cloudy due to the formation of tin hydroxide.
A fresh solution of stannous fluoride be prepared for each patient.
To prepare 8% stannous fluoride solution, the content of one
capsule which is 0.8 grams (‘0’ No. of gelation capsule) is dissolved
in 10 ml of distilled water in a plastic container.
Technique of application (Muhler’s technique) :
1. Each tooth surface is cleaned with pumice or other dental
cleaning agent for 5 to 10 seconds;
2. Unwaxed dental floss is passed between the interproximal areas;
3. Teeth are isolated and dried with air;
4. Stannous fluoride is applied using the paint-on technique and the
solution is kept for 4 minutes. Repeat applications are made
every 6 months or more frequently if the patient is susceptible to
Advantages of stannous fluoride :
Using an 8% stannous fluoride solution at 6 to 12 months
intervals conforms to the practicing dentist’s usual patient –
Administrative difficulties are avoided.
Disadvantages of stannous fluoride :
1. In aqueous solution the material is not stable;
2. 8% solution is quite astringent and disagreeable in taste, its
application is unpleasant;
3. The solution occasionally causes a reversible tissue irritation
manifested by gingival blanching;
4. Causes pigmentation of teeth which has a characteristic light
ACIDULATED PHOSPHATE FLUORIDE (APF) :
Method of preparation of acidulated phosphate fluoride :
An aqueous solution of acidulated phosphate fluoride is
prepared by dissolving 20 grams of sodium fluoride in 1 liter
of 0.1 M phosphoric acid and to this is added 50%
hydrofluoric acid to adjust the pH at 3.0 and fluoride ion
concentration at 1.23%. It is also called as Brudevold’s
For the preparation of acidulated phosphate fluoride gel, a
gelling agent methylcellulose or hydroxyethyl cellulose is
added to the solution.
Technique of application :
Acidulated phosphate fluoride is recommended for application at 6 or 12
Oral prophylaxis is done;
The teeth to be treated are completely isolated and thoroughly dried
Clinical application of APF gels should be done using trays that fit the
patient’s upper and lower dental arches. A disposable foam-lined tray
To reduce ingestion of fluoride, a minimum amount of fluoride gel that
will permit complete coverage of the tooth surfaces should be
After the trays have been properly positioned saliva ejector is used to
evacuate the stimulated saliva and excess fluoride;
It is reapplied every 15-30 seconds so as to keep the teeth moist with
the fluoride solution throughout the 4 minute period;
The patient is instructed not to eat, drink or rinse his mouth for at least
Advantages of acidulated phosphate
Requires only 2 application in a year;
The gel preparation can be self applied and
thus the cost of application also gets
It has the ability to deposit fluoride in
enamel to a deeper depth;
Disadvantages of acidulated
phosphate fluoride :
Practical difficulties like the teeth should be
kept wet for for 4 minutes;
It is acidic, sour and bitter in taste;
It cannot be stored in glass containers.
Recommendation For Topical
According to Lecompte (1987), the recommendation for Topical Application of
high potency fluorides are:-
1. Not more than 2gm of gel per tray or approximately 40% of tray capacity should
be dispended. Even more conservative amount should be considered for small
2. To prevent the swallowing of saliva during 4 min topical application , use of
Saliva Ejector is recommended.
3. Following the 4 min of application procedure, the patient should be instructed to
expectorate thoroughly for 30 sec-1 min, regardless the use of suction cause the
Expectoration is the only single most effective way of reducing orally retained
4. When utilising custom individually fitted trays for patients requiring daily or
weekly application of a high fluoride concentration product utilise only 5-10
drops of products per tray.
SELF-APPLIED TOPICAL FLUORIDES
The active agent was NaF which had been added to a
conventional dentifrice containing dicalcium phosphate
as the abrasive.
Mouth rinsing is a practical
and effective means for self-
application of fluoride.
Persons excluded from the
practice are :
1. Children under 6 years of
2. Those of any age who
cannot rinse because of
problems or other
Method of use :
1. Rinse daily with 1 teaspoonful (5 ml) after brushing
2. Swish between teeth with lips tightly closed for 60
Flouride rinses can be used as daily mouth rinse by
community and fortnightly in schools.
30-40% average reduction in dental caries incidence.
Requires community participation.
• Dental fluorosis is a developmental
disturbance of dental enamel caused by
excessive exposure to high concentrations
of fluoride during tooth development.
• Due to Inappropriate use of fluoride-
containing dental products.
When fluoride appropriately used, is safe and effective agent that can be
used to prevent and control dental caries. Fluoride has been contributing to
improve the dental health of persons all over the world. Fluoride is needed
regularly to prevent and protect the teeth from being decayed.