TOPICAL FLUORIDES
INTRODUCTION
 Fluorides have been proved to the single
most effective weapon in our limited
arsenal of anticaries agents.
 Dental profession has also been cognizant
of the limitations of fluoridation of
community water supply.
 In 1941 began the era of topical fluorides.
 In India >70% of population cannot be
covered by water fluoridation.
 The term topical fluoride therapy refers
to the use of systems containing relatively
large concentrations of fluoride that are
applied locally or topically, to erupted tooth
surfaces to prevent the formation of dental
caries.
 This term encompasses the use of the
fluoride rinses, dentifrices, pastes, gel and
solution that are applied in various
manners.
- Haris and Garcia Goday.
RATIONALE
 Is to speed the rate and increase the
concentration of fluoride acquisition above
the level which occurs naturally.
 Best time to apply topical fluorides is soon
after eruption.
 Periodic applications of fluoride would
enable vulnerable enamel sites that are
partially demanerialized to accumulate
fluoride.
RATIONALE
 Bibby in 1942 was the first to
demonstrate that the repeated
application of sodium or potassium
fluoride to teeth of children
significantly reduced their caries
prevalence.
PROFESSIONALLY APPLIED
FLUORIDES
 Dental personnel have been applying
fluoride to the teeth since the early
1940’s.
 Currently recognized agents include
various fluoride solutions , gels and
varnishes.
SODIUM FLUORIDE
 In 1940 Volker et al showed invitro
that the solubility of enamel could be
appreciably reduced by treating it
with a fluoride solution.
 Milestone studies were conducted by
Bibby (1941) and Knutson
(1942,1947,1948).
METHOD OF PREPARATION OF
SODIUM FLUORIDE
 2% NaF solution can be prepared by
dissolving 20 g of powder in 1 liter of
distilled water in a plastic bottle.
METHOD OF APPLICATION OF
SODIUM FLUORIDE – KNUTSON’S
TECHNIQUE.
 Cleaning and polishing of the teeth.
 Opposing quadrants are isolated with
cotton rolls and teeth are dried
thoroughly.
 2% NaF is applied with cotton
applicator and dried on the teeth for
4 min.
 Procedure is repeated for remaining
quadrants.
METHOD OF APPLICATION OF
SODIUM FLUORIDE – KNUTSON’S
TECHNIQUE.
 Patient is instructed to avoid eating,
drinking or rinsing for 30 minutes.
 2nd, 3rd and 4th applications are given
at weekly intervals.
 A full series of 4 treatments is
recommended at ages 3,7,11 and 13
years.
MECHANISM OF ACTION OF NaF
SOLUTION.
 It reacts with HA crystals to form CaF2.
 Due to the high concentration of fluoride in 2%
NaF to which the solubility product of CaF2 get
excluded fast and the initial reaction is
followed by drastic reduction in its rate and the
phenomenon is called “Choking Off”
 Further calcium fluoride reacts with HA to form
fluoridated HA.
ADVANTAGES
 Relatively stable when kept in a plastic
container.
 Taste is well accepted, non irritating and does
not cause discoloration of tooth structure.
 Multiple chair procedures in public health
programmes.
 The series of treatments must be repeated
only 4 times rather than at annual or
semiannual intervals.
DISADVATANGES
 The major disadvantage is that the
patient must make 4 visits to the
dentist within a relatively short time.
STANNOUS FLUORIDE
 Muhler et al in 1947 found that
stannous fluoride to be 3 times more
effective than sodium fluoride
METHOD OF PREPARATION OF
STANNOUS FLUORIDE
 Freshly prepared before each use.
 Gelatin capsules are priorly filled with
0.8g powdered stannous fluoride and
are stored.
 Just before application, the content of
one capsule is dissolved in 10ml of
distilled water in a plastic container.
METHOD OF APPLICATION OF
STANNOUS FLUORIDE BY MUHLER
 Thorough prophylaxis.
 Isolation of teeth
 Quadrant or half mouth treated at
one time.
 Applied with cotton applicators, and
kept for 4 minutes.
 Recommended frequency is
once/year.
MECHANISM OF ACTION OF
STANNOUS FLUORIDE
 Stannous fluoride with HA in addition
to fluoride, the tin of stannous
fluoride also reacts with enamel and a
new crystalline product formed that is
stannous-tri-flurophosphate which is
more resistant to decay than enamel.
 Tin hydroxy phosphate is also formed
and is responsible for metallic taste.
ADVANTAGES
 The procedure frequency complies
with one year recall appointment
schedule.
DISADVANTAGES
 Material is not stable in aqueous
solutions.
 Since 8% solution is quite astringent
and disagreeable in taste.
 Occasionally causes a reversible
tissue irritation.
 Pigmentation of teeth.
ACIDULATED PHOSPHATE
FLUORIDE
 In 1963 Brudevold et al found out
that phosphate containing fluoride
acid solution was of maximum
beneficial effect.
PRACTICAL DIFFICULTIES WITH
THE SOLUTION
 Teeth must be kept wet with solution for 4
minutes.
 APF solution is acidic, sour and bitter in
taste.
 Repeated applications necessitates the use
of suction.
 Multiple chair programme and expensive.
 To overcome all these problems APF gels
were introduced.
ACIDULATED PHOSPHATE
FLUORIDE
APF gel
1. Relatively costly
APF solution
1. Relatively cheaper
2. Readily available
(imported in India)
2. Prepared easily
3. Self application is
possible
3. Applied by dentist /
Auxiliary staff
Preparation of ACIDULATED
PHOSPHATE FLUORIDE
 Contains 1.23% fluoride in 0.1M phosphoric
acid at a pH of 3
 Prepared by dissolving 20 mg of NaF in liter
of 0.1M phosphoric acid.
 To this is added 50% hydrofluoride to
adjust to pH at 3 and F concentration to
1.23%
 For the preparation of APF gel, a gelling
agent methylcellulose or Hydroxyethyl
cellulose is to be added.
Method of application of
ACIDULATED PHOSPHATE
FLUORIDE
 Thorough prophylaxis
 Teeth are isolated
 APF solution is applied and the teeth
are kept moist for 4 minutes.
 Floss may be used for inter proximal
areas.
 Semiannual applications
 Gel can be used as self applications
using trays.
Mechanism of action
 Initially leads to dehydration and shrinkage
in the volume of HAP crystals which further
on hydrolysis forms Dicalcium phosphate
dihydrate (DCPD). This leads to formation
of FA.
 For deeper penetration, a continuous
supply of fluoride is required. So APF has to
be applied every 30 seconds and teeth be
kept wet for 4 mins.
ADVANTAGES
 Requires only 2 applications in a year
and is thus suited for most dental
office routines.
 The gel can be self applied and thus
the cost of application also gets
reduced.
DISADVANTAGES
 Teeth should be kept wet for 4 min
which increases chair-side time.
 Acidic, sour and bitter in taste.
 Cannot be stored in glass containers.
 Causes surface alterations of many
restorative materials.
COMPARISON
Characteristics
Sodium F
Stannous F
APF
1.
2.
3.
4.
5.
2%
9200
4 at weekly
Bland
Stable
8%
19,500
1 or 2/yr
Disagreeable
Unstable
1.23%
12,300
1 or 2/yr
Disagreeable
Stable in
plastic
container
No
Percentage
PPM F
Frequency
Taste
Stability
6. Tooth
No
pigmentation
7. Gingival
No
irritation
Yes
Occasional
transient
No
MONOFLUOROPHOSPHATE
 Fluoride atom is covalently bonded to
phosphorous atom.
 It is unique because only fluorapatite
forms even when it is applied to
enamel in high concentration or at
low pH.
FLUORIDE VARNISHES
 Fluoride retention in enamel was
found to be enhanced by sealing the
surface of teeth with 2 – ethyl – 2
cyanoarylate after fluoride
applications.
FLUORIDE VARNISHES
 2 most commonly used varnishes
are:
1. Duraphat (2.26% F)
2. Fluorprotector (0.7%)
COMPOSITION OF FLUORIDE
VARNISH
 Duraphat:
- Natural resin.
- A neutral colophomium base,
containing 5% wt NaF (2.26% F)
dissolved in ethanol.
- Banana flavoured and sets on tooth
surface in a yellow – brown film.
COMPOSITION OF FLUORIDE
VARNISH
 Fluorprotector:
- polyurethane based transparent
resin, containing 0.1% Fluoride as
difluorosilane (0.9%wt) dissolved in
ethyl acetate and isoamyl propionate
solution.
COMPOSITION OF FLUORIDE
VARNISH
 Biflurid:
- contains 2.7% weight as sodium fluoride
and 2.92% as calcium fluoride.
 Carex:
- contains 1.8% of NaF
 Durafluor
- 5% NaF in a alcoholic suspension of
natural resins
 Fluoritop
marketed in India.
COMPOSITION OF FLUORIDE
VARNISH
 CAVITY SHIELD:
- Most recent.
- 5% NaF in a resinous base.
Advantages:
- avoids wastage.
- prevents over application.
- reduces chance of over ingestion.
TECHNIQUE OF VARNISH
APPLICATION
 Prophylaxis
 Teeth dried but not isolated with cotton.
 A total of 0.3-0.5 ml of varnish equivalent to
6.9-11.5 mg F is required to cover the full
dentition.
 Applied on lower arch first
 Wait for 4 min
 Not to rinse or drink anything for 1 hour and
not to eat anything solid upto 18 hours.
Mechanism of action
 When applied, a reservoir of F ions
gets build up around the enamel of
the teeth.
 From this F keeps on slowly releasing
and continuously reacting with HA
crystals.
 A part of calcium fluoride so formed
in low concentration further reacts
with crystals of HAP and forms FAP.
Clinical considerations
 Patients who appear to be at high risk
to caries: manifested by bacteriologic
findings or development of several
new cavities or areas of
demineralization, xerostomia caused
by medications, metabolic
disturbances such as sjogren’s
syndrome or radiation treatment.
RECOMMENDATIONS
1.
Caries active individuals
2.
Children shortly after periods of tooth eruption,
especially those who are not caries free.
3.
Those on medication or have received radiation.
4.
After periodontal surgery
5.
Patients with fixed or removable prosthesis.
6.
Patient with eating disorder.
7.
Mentally and physically challenged individuals.
SELF APPLIED TOPICAL
FLUORIDES
FLUORIDE DENTIFRICES
 1955 – introduced for sale over the
counter.
 The most commonly evaluated are:
- sodium fluoride
- stannous fluoride
- sodium monoflurophosphate
- organic amine fluoride
DENTIFRICES CONTAINING
MONOFLUOROPHOSPHATE
 Preferred chemical form of fluoride
 Since 1969
 Does not occur in nature
 In recent formulations aluminium oxide
abrasive have been used.
FLUORIDE MOUTHRINSES
 First described by Bibby in 1946
 Most widely used caries preventive
public health methods
 ADA acceptance in 1975 for neutral
NaF and APF mouthrinses.
 Later stannous fluoride was also
accepted.
Sodium fluoride mouthrinses
 0.2% NaF for weekly use or 0.05% NaF for
daily use.
 Intended to use by forcefully swishing 10ml
of the liquid around the mouth for 60 sec
before expectorating it.
 Preparation: by dissolving 200mg of NaF
tablet (10mg NaF and the rest lactose as
filler) in 5teaspoons of fresh clean water
(approx 25ml)
 Caries reduction was less than 25 – 30%.
Recommendations for fluoride
mouthrinses
 Patients in fluoride deficient areas.
 A swish and swallow technique should be
followed if the concentration of drinking
water is 0.3ppm or less.
 Beneficial for patients with increased caries
risk e.g.: for those undergoing orthodontic
treatment as well as patients under
radiotherapy.
FLUORIDE GELS
 Fluoride gels for self application include
neutral sodium fluoride and APF with a
fluoride concentration of 5,000ppm and
stannous fluoride which has a conc of
1000ppm.
 Applied in trays or brushed on teeth.
 Patient should be cautioned to expectorate.
 Not recommended for children 6 years and
younger.
FLUORIDE TOXICITY
 Used in excessive quantities, fluorides can
produce toxic and even lethal outcomes when
ingested, inhaled or absorbed into the body.
 Probable toxic dose (PTD): defined as the
dose of ingested fluoride that should trigger
immediate therapeutic intervention and
hospitalization because of the likelihood of
serious toxic consequences.
 Adults:
CLD=32 to 64 mg of fluoride/kg bodywt
320 mg for 10kg child
STD= 8 to 16 mg F/kg body wt.
EMERGENCY TREATMENT
Miligram F ion per
KG body weight
Treatment
Less than 5 mg/kg
1. Give calcium orally (milk) and observe.
2. Induced vomotting not necessary.
More than 5 mg/kg
1. Empty stomach by induced vomiting
with emetic
2. Give soluble calcium in any form.
3. Admit to Hospital and observe.
More than 15 mg/kg
1.
2.
3.
4.
Admit to hospital immediately.
Induce vomiting
Begin cardiac monitoring
Administer IV 10ml of 19% calcium
gluconatesolution.
5. Adequate urine output should be
maintained.
6. General supportive measures for shock.
Acute toxicity
 Symptoms:




Gastrointestinal
Neurological
CVS
Blood chemistry
Chronic toxicity
 Results from long term ingestion of
fluoride.
 Dental fluorosis
 Skeletal fluorosis
 Dental fluorosis is caused by excessive intake
of fluoride during tooth development.
 Ingestion of fluoride concentration 2 or 3 times
greater than the recommended amount caused
white flecks and chalky opaque areas on the
tooth enamel (mild fluorosis).
 Consumption of water containing 4 times the
recommended amount of fluoride causes a
brown pitted corroded appearance on the
enamel surface.
Skeletal fluorosis
 Known as knock knee syndrome.
 Osteosclerosis, ossification of
tendons, pain and stiffness of joints,
outward bending of legs, continuous
back pain.