BY-
MALIK ABDUL
FINAL YR

 Member of the halogen family with relative atomic
weight 19
 Atomic number – 9
 Fluorine derived from Latin term ‘fluore’ meaning,
“to flow”
 Occurs in combined form such as Fluorspar[fluorite
CaF2], Fluorapatite[Ca10F2(PO4)6], Cryolite[NaAlF6]
The element Fluorine
 Dr. Fredrick McKay (Colorado Springs, Colorado, USA) –
1901 saw the stains on the teeth of his pts. The local
inhabitants called it the ‘Colorado stain’.
 He called the stain “mottled enamel”.
 First systemic endeavour to investigate the lesion was
made by the Colorado springs dental society in 1902
 He approached one of the America’s foremost authorities
on dental enamel, Dr. Greene Vardiman Black.
 Black asked him to send the mottled teeth for
examination after that he agreed to attend the Colorado
state dental association meeting in 1909, and promised to
spend some weeks in Colorado springs before the
meeting.
HISTORY

 In 1931 U.S. govt appointed Dr. Trendly H Dean to
continue the work of Mckay.
 Dean conducted survey in 22 cities in USA.

 Canned fish products – Salmon & Sardin – 20-
40mg/kg
 Fish protein concentrates – 370mg/kg
 Jowar, banana, potatoes
 Rock salt (40-200ppm)
 Dried tea leaves (100-400ppm)
Sources of fluoride

 Increase enamel resistance (or) reduction in enamel
solubility
 Increased rate of posteruptive maturation
 Remineralization of incipient lesions
 Interference with plaque microorganisms
 Modification with tooth morphology
Mechanism of action of
fluorides

 Fluoride inhibits demineralization in several ways,
 By reducing bacterial acid production
 By reducing the equilibrium solubility of apatite
 By the fluoridation of apatite crystal surfaces
reducing the dissolution rate whether or not there is
reduced solubilty of the bulk material
Increased enamel resistance/Reduction
in enamel solubility

 Importance of fluoride in maturation process lies in
its ability to increase the rate of mineralization of
hypomineralized areas
 Posteruptive maturation involves deposition of
minerals into hypomineralized areas
Increased rate posteruptive
maturation

 Fluoride plays critical role in the reducing of dental
caries by enhancing remineralization.
 Remineralization, the deposition of minerals into
previously damaged areas of the tooth is a process
that results in enamel solubility
Remineralization of incipient
lesions

 Fluoride has been known to inhibit bacterial
enzymatic processes involved in carbohydrate
metabolism
 In high conc., fluoride is bactericidal. Helps reduce
plaque
 In lower conc., fluoride is bacteriostatic. Helps
control the growth of bacteria without destroying
them.
Interferance with
microorganisms

 If fluoride is ingested during the tooth development,
there is some evidence to suggest the fromation of a
more caries resistant tooth slightly smaller with
shallow fissures.
Modification in tooth
morphology
FLUORIDE DELIVERY METHODS
Fluoride can be delivered as…
(A) Topical Fluorides
(B) Systemic Fluorides
TOPICAL FLUORIDES SYSTEMIC FLUORIDES
 These are placed directly
on the teeth
 Some preparations
provide high or low
concentrations of fluoride
over a short period of
time
 These circulate through
the blood stream and are
incorporated into
developing teeth
 They provide a low
concentration of fluoride
over a long period of
time

TOPICAL FLUORIDES
By the definition the term “topically applied fluorides”
is used to describe those delivery systems which
provide fluoride for a local chemical reaction to
exposed surfaces of the erupted dentition.
INDICATIONS
 Caries active individuals
 Children shortly after period of tooth eruption
 Those who take medication that decrease salivary
flow or have received radiation to head and neck
 After periodontal surgery when roots of teeth have
been exposed
 Patients with fixed or removable prosthesis and after
placement or replacement of restorations
 Patients with an eating disorder or who are
undergoing a change in lifestyle which may affect
eating or oral hygiene habits conductive to good oral
health
 Mentally and physically challenged individuals
TOPICAL FLUORIDE PRODUCTS ARE
DIVIDED INTO 2 CATEGORIES
(A) Professionally applied
 Introduced by Bibby in 1942
 Dispensed by dental professionals in the dental office
and usually involve the use of high fluoride
concentration products ranging from 5000-19000 ppm
which is equivalent to 5-9 mg F/ml
(B) Self applied
 Include fluoride dentifrices, mouth rinses & gels
 Are low fluoride concentration products ranging from
200-1000ppm or 0.2-1 mgF/ml.
RATIONALE FOR USING TOPICAL
FLUORIDE AGENTS
 To speed up the rate and increase the
concentration of fluoride acquisition above
the level which occurs naturally
 The initial caries lesion characterized by a
white spot is porous and accumulates
fluoride at a much higher concentration than
adjacent sound enamel hence periodic
application of fluoride would enable
vulnerable enamel sites that are partially
demineralized to accumulate fluoride
PROFESSIONALLY APPLIED
FLUORIDES
FLUORIDE VEHICLES
 AQUEOUS SOLUTIONS AND GELS
 Gel adheres to the tooth surface for a considerable
amount of time and eliminates the continuous wetting
of enamel surfaces when solutions are used
 2 or 4 quadrants can be treated simultaneously when
trays are used for gel application which results in
substantial saving of time
 Thyxotrophic solutions are not gels but have high
viscosity under storage conditions and become fluid
under high stress
 Thyxotrophic solutions are more stable at lower pH
and do not run off the tray as readily as conventional
gels
GELS
FLUORIDATED PROPHYLACTIC PASTES
 If prophylaxis pastes
containing fluoride are
used, the lost fluoride is
replenished & there is a
significant gain in the
concentration of
fluoride.
FOAM
 Developed to minimize the risk of fluoride over
dosage as well as to maintain the efficacy of topical
fluoride treatment.
 ADVANTAGES:
 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 interproximal surfaces.
 It doesn’t require suctioning so it offers advantages for
home use
FOAM
FLUORIDE VARNISH
 It was first developed by Schimdt in Europe in 1964
 Increasing the time of contact between enamel surface
& topical fluoride agents favors the deposition of
fluorapatite & fluorhydroxyapatite.
Technique:
 After prophylaxis teeth are dried but not isolated with
cotton rolls since varnish sticks to cotton
 Total of 0.3-0.5 ml of varnish is required to cover full
dentition
 Application is done first done on lower arch then
upper, using single tufted small brush, starting with
proximal surfaces
 Patient is asked to sit with mouth open for 4 min to let
Duraphat set on teeth
FLUORIDE
VARNISH
 Patient is asked to not rinse or drink anything for one hour
and advised liquid diet till next morning
 DURAPHAT:
It is a first fluoride varnish developed in germany, viscous
yellow material, containing 22,600 ppm fluoride as sodium
fluoride in a neutral colophonium base.
 FLUORPROTECTOR:
It is a clear polyurethane based product containing 7000
ppm fluoride from difluorosilane.
It is dispensed in 1ml ampoules each ampoule containing
6.21mg of fluoride.
 CAREX:
It has low fluoride concentration than duraphat & has
equal efficacy to that of duraphat as caries preventive
agent
TOPICAL FLUORIDES USED IN PREVENTIVE
DENTISTRY:
 SODIUM FLUORIDE
 STANNOUS FLUORIDE
 ACIDULATED PHOSPHATE FLUORIDE
 AMINE FLUORIDE
1) NEUTRAL SODIUM FLUORIDE (NaF)
 Fluoride concentration - 9200ppm
 A minimum of four applications with a 2% NaF
solution gives a caries reduction of about 30%
 METHOD OF PREPARATION
 It is prepared by dissolving 20 gms of NaF powder in
1L of distilled water in a plastic bottle
 TECHNIQUE - KNUTSON’S TECHNIQUE
 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.
 MECHANISM OF ACTION :
 When NaF is applied on tooth surface it reacts with
hydroxyapatite crystals in enamel to form Calcium fluoride
(CaF2) which is the dominant product of the reaction
 As thick layer of CaF2 forms, it interferes with further diffusion
of fluoride from the topical fluoride solution to react with
hydroxyapatite and blocks further entry of fluoride ions. This
sudden stop of the entry of fluoride is termed as ‘chocking off
effect’
 CaF2 acts as a reservoir and fluoride slowly leeches out of it
 The CaF2 formed reacts with hydroxyapatite fluoridated
hydroxyapatite increases the concentration of fluoride on
enamel surface prevents caries
 ADVANTAGES :
 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 intervals.
 DISADVANTAGES:
 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 time.
2) STANNOUS FLUORIDE (SnF2)
 Fluoride concentration-19500ppm
 Stannous fluoride has been used at 8% and 10%
concentrations
 METHOD OF PREPARATION:
 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 - MUHLER’S TECHNIQUE
 Each tooth surface is cleaned with pumice or other
dental cleaning agent for 5 to 10 seconds;
 Unwaxed dental floss is passed between the
interproximal areas;
 Teeth are isolated and dried with air;
 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 caries.
 MECHANISM OF ACTION:
 When SnF2 is applied in low concentration
tinhydroxyapatite, which gets dissolved in oral tissues
 At very high concentration Ca trifluorostannate forms
along with tin tri-fluorophosphate
 Tin trifluorophosphate is responsible for making the
tooth structure more stable and less susceptible to
decay
 CaF2 is the end product both at low and high
concentration which reacts with hydroxyapatite and a
small fraction of fluorhydroxyapatite also gets formed
 ADVANTAGES :
 Using an 8% stannous fluoride solution at 6 to 12 months
intervals conforms to the practicing dentist’s usual patient –
recall system;
 Administrative difficulties are avoided.
 DISADVANTAGES :
 In aqueous solution the material is not stable;
 8% solution is quite astringent and disagreeable in taste, its
application is unpleasant;
 The solution occasionally causes a reversible tissue
irritation manifested by gingival blanching;
 Causes pigmentation of teeth which has a characteristic
light brown colour
3) ACIDULATED PHOSPHATE FLUORIDE (APF)
 Fluoride concentration-12300 ppm
 METHOD OF PREPARATION
An aqueous solution is 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 solution
For the preparation of acidulated phosphate fluoride
gel, a gelling agent methylcellulose or hydroxyethyl
cellulose is added to the solution.
 TECHNIQUE
 APF is recommended for application at 6 or 12 months
interval
 Oral prophylaxis is done
 Teeth to be treated are completely isolated and
thoroughly dried with air
 Application of gel is done using trays; disposable
foam lined trays are preferred
 It is reapplied every 15-30sec so as to keep the teeth
moist with the fluoride solution throughout the four
min period
 The patient is instructed to eat, drink or rinse his
mouth for atleast 30 min
FLUORIDE
TRAYS
 MECHANISM OF ACTION
 When APF is applied to teeth it initially leads to
dehydration and shrinkage in the vol of hydroxyapatite
crystals which on hydrolysis forms an intermediate
product called Dicalcium phosphate dihydrate(DCPD)
 DCPD is highly reactive and starts forming immediately
after APF is applied
 Fluoride penetrates into the crystals more deeply through
the openings produced by shrinkage and forms fluorapatite
 For the conversion of whole DCPD formed into
fluorapatite, a deeper penetration and continuous supply of
fluoride is required. Because of this reason APF is applied
every 30 sec and the teeth have to be kept wet for 4 min
 ADVANTAGES
 Requires only 2 application in a year;
 The gel preparation can be self applied and thus the
cost of application also gets reduced;
 It has the ability to deposit fluoride in enamel to a
deeper depth;
 DISADVANTAGES :
 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.
4) AMINE FLUORIDE
 They are cariostatic agents
 Some of them are surface active agents i.e. they have
an affinity for enamel and thus will hold the fluoride
for a longer time against the tooth
 They also have anti bacterial properties. Reduced
plaque formation and anti glycolytic activity is also
reported with these compounds
 Amine fluorides have been tested in dentifrices,
mouthrinses and topical gels where they are either
brushed on teeth or applied with a tray but it is not
known if they are superior to the other currently
available fluoride agents
Characteristics Sodium fluoride Stannous
fluoride
Apf
Percentage 2% 8% 1.23%
Fluoride
concentration
(ppm)
9200 19500 12300
ph neutral 2.4-2.8 3.0
Frequency of
application
4 at weekly
intervals 3,7,11 &
13 yrs
biannually biannually
Adverse effects no Tooth
pigmentation
Gingival
irritation
no
Caries reduction 30% 32% 28%
RECOMMENDATIONS FOR TOPICAL
APPLICATION
 No more than 2 g of gel per tray or approximately
40% of tray capacity.
 Pt. may have the need to swallow during the 4min
procedure, saliva ejector is recommended.
 After the procedure the pt. be instructed to
expectorate thorougly for from 30sec to 1min.
SELF APPLIED TOPICAL
FLUORIDES
 Dentifrices
 Mouth rinses
 Gels
 DENTIFRICES
 The first clinical trial of fluoride dentifrice was
initiated by Bibby in 1942
 The various compounds used in dentifrice are sodium
fluoride, stannous fluoride, monofluorophosphate and
amine fluoride
 A 200g tube of Colgate contains 1000ppm of fluoride
with the fluoride compound as Monofluorophosphate
 A single brushing with a full ribbon of paste on
a brush head provides about one gram of
toothpaste and will expose the individual to
approximately 1mgF
 For young children non fluoridated and non
abrasive toothpaste is recommended till the
child is 4 years of age
 After 6 years of age fluoridated toothpaste
should be used
 The amount should be pea sized and the paste
should be pressed into the bristles and not on
top of the brush
 MOUTHRINSES
 Fluoride mouthrinsing is one of the most widely used
caries preventive public health methods
 Caries preventive agents used are Neutral sodium
fluoride, Acidulated phosphate fluoride and Stannous
fluoride
 Sodium fluoride mouthrinses
 Formulated at concentrations of
0.2%(900 ppm F) for weekly use
0.05%(225 ppm F) for daily use
 These are used by forcefully swishing 10ml of the liquid
around the mouth for 60 sec before expectorating it
 Recommendations for fluoride mouthrinses
 Rinse and expectorate technique used for patients in
fluoride deficient communities
 In patients with increased caries risk e.g. those undergoing
orthodontic treatment or radiotherapy
 FLUORIDE GELS
 Fluoride gel products include neutral
sodium fluoride and acidulated
phosphate fluoride with a fluoride
concentration of 5000 ppm and
stannous fluoride with a
concentration of 1000 ppm
 The gels are either applied in trays or
brushed on teeth
 Professionally applied – given twice
a year
 Self applied – once a day or more
 Home fluoride gels are not
recommended for children below 6
yrs and younger
Limitations of fluoride gels
 They violate the principle of delivering low
concentration of fluoride at regular intervals
 Toxicity hazard
 Tedious to use on daily basis
Conclusion
 Fluoridation is universally accepted by the dentists
and other medical professionals as being useful in
preventing tooth decay
 They can be used in areas where there are no
central water supplies, where the fluoride conc. of
well water is low
 Topically applied fluoride has more effect
compared to systemic fluorides
 Topical fluorides are more economical.
 But cannot be done on a large basis
Topical fluordes

Topical fluordes

  • 1.
  • 2.
      Member ofthe halogen family with relative atomic weight 19  Atomic number – 9  Fluorine derived from Latin term ‘fluore’ meaning, “to flow”  Occurs in combined form such as Fluorspar[fluorite CaF2], Fluorapatite[Ca10F2(PO4)6], Cryolite[NaAlF6] The element Fluorine
  • 3.
     Dr. FredrickMcKay (Colorado Springs, Colorado, USA) – 1901 saw the stains on the teeth of his pts. The local inhabitants called it the ‘Colorado stain’.  He called the stain “mottled enamel”.  First systemic endeavour to investigate the lesion was made by the Colorado springs dental society in 1902  He approached one of the America’s foremost authorities on dental enamel, Dr. Greene Vardiman Black.  Black asked him to send the mottled teeth for examination after that he agreed to attend the Colorado state dental association meeting in 1909, and promised to spend some weeks in Colorado springs before the meeting. HISTORY
  • 4.
      In 1931U.S. govt appointed Dr. Trendly H Dean to continue the work of Mckay.  Dean conducted survey in 22 cities in USA.
  • 5.
      Canned fishproducts – Salmon & Sardin – 20- 40mg/kg  Fish protein concentrates – 370mg/kg  Jowar, banana, potatoes  Rock salt (40-200ppm)  Dried tea leaves (100-400ppm) Sources of fluoride
  • 6.
      Increase enamelresistance (or) reduction in enamel solubility  Increased rate of posteruptive maturation  Remineralization of incipient lesions  Interference with plaque microorganisms  Modification with tooth morphology Mechanism of action of fluorides
  • 7.
      Fluoride inhibitsdemineralization in several ways,  By reducing bacterial acid production  By reducing the equilibrium solubility of apatite  By the fluoridation of apatite crystal surfaces reducing the dissolution rate whether or not there is reduced solubilty of the bulk material Increased enamel resistance/Reduction in enamel solubility
  • 8.
      Importance offluoride in maturation process lies in its ability to increase the rate of mineralization of hypomineralized areas  Posteruptive maturation involves deposition of minerals into hypomineralized areas Increased rate posteruptive maturation
  • 9.
      Fluoride playscritical role in the reducing of dental caries by enhancing remineralization.  Remineralization, the deposition of minerals into previously damaged areas of the tooth is a process that results in enamel solubility Remineralization of incipient lesions
  • 10.
      Fluoride hasbeen known to inhibit bacterial enzymatic processes involved in carbohydrate metabolism  In high conc., fluoride is bactericidal. Helps reduce plaque  In lower conc., fluoride is bacteriostatic. Helps control the growth of bacteria without destroying them. Interferance with microorganisms
  • 11.
      If fluorideis ingested during the tooth development, there is some evidence to suggest the fromation of a more caries resistant tooth slightly smaller with shallow fissures. Modification in tooth morphology
  • 12.
    FLUORIDE DELIVERY METHODS Fluoridecan be delivered as… (A) Topical Fluorides (B) Systemic Fluorides
  • 13.
    TOPICAL FLUORIDES SYSTEMICFLUORIDES  These are placed directly on the teeth  Some preparations provide high or low concentrations of fluoride over a short period of time  These circulate through the blood stream and are incorporated into developing teeth  They provide a low concentration of fluoride over a long period of time
  • 14.
     TOPICAL FLUORIDES By thedefinition the term “topically applied fluorides” is used to describe those delivery systems which provide fluoride for a local chemical reaction to exposed surfaces of the erupted dentition.
  • 15.
    INDICATIONS  Caries activeindividuals  Children shortly after period of tooth eruption  Those who take medication that decrease salivary flow or have received radiation to head and neck  After periodontal surgery when roots of teeth have been exposed  Patients with fixed or removable prosthesis and after placement or replacement of restorations  Patients with an eating disorder or who are undergoing a change in lifestyle which may affect eating or oral hygiene habits conductive to good oral health  Mentally and physically challenged individuals
  • 16.
    TOPICAL FLUORIDE PRODUCTSARE DIVIDED INTO 2 CATEGORIES (A) Professionally applied  Introduced by Bibby in 1942  Dispensed by dental professionals in the dental office and usually involve the use of high fluoride concentration products ranging from 5000-19000 ppm which is equivalent to 5-9 mg F/ml (B) Self applied  Include fluoride dentifrices, mouth rinses & gels  Are low fluoride concentration products ranging from 200-1000ppm or 0.2-1 mgF/ml.
  • 17.
    RATIONALE FOR USINGTOPICAL FLUORIDE AGENTS  To speed up the rate and increase the concentration of fluoride acquisition above the level which occurs naturally  The initial caries lesion characterized by a white spot is porous and accumulates fluoride at a much higher concentration than adjacent sound enamel hence periodic application of fluoride would enable vulnerable enamel sites that are partially demineralized to accumulate fluoride
  • 18.
    PROFESSIONALLY APPLIED FLUORIDES FLUORIDE VEHICLES AQUEOUS SOLUTIONS AND GELS  Gel adheres to the tooth surface for a considerable amount of time and eliminates the continuous wetting of enamel surfaces when solutions are used  2 or 4 quadrants can be treated simultaneously when trays are used for gel application which results in substantial saving of time  Thyxotrophic solutions are not gels but have high viscosity under storage conditions and become fluid under high stress  Thyxotrophic solutions are more stable at lower pH and do not run off the tray as readily as conventional gels
  • 19.
  • 20.
    FLUORIDATED PROPHYLACTIC PASTES If prophylaxis pastes containing fluoride are used, the lost fluoride is replenished & there is a significant gain in the concentration of fluoride.
  • 21.
    FOAM  Developed tominimize the risk of fluoride over dosage as well as to maintain the efficacy of topical fluoride treatment.  ADVANTAGES:  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 interproximal surfaces.  It doesn’t require suctioning so it offers advantages for home use
  • 22.
  • 23.
    FLUORIDE VARNISH  Itwas first developed by Schimdt in Europe in 1964  Increasing the time of contact between enamel surface & topical fluoride agents favors the deposition of fluorapatite & fluorhydroxyapatite. Technique:  After prophylaxis teeth are dried but not isolated with cotton rolls since varnish sticks to cotton  Total of 0.3-0.5 ml of varnish is required to cover full dentition  Application is done first done on lower arch then upper, using single tufted small brush, starting with proximal surfaces  Patient is asked to sit with mouth open for 4 min to let Duraphat set on teeth
  • 24.
  • 25.
     Patient isasked to not rinse or drink anything for one hour and advised liquid diet till next morning  DURAPHAT: It is a first fluoride varnish developed in germany, viscous yellow material, containing 22,600 ppm fluoride as sodium fluoride in a neutral colophonium base.  FLUORPROTECTOR: It is a clear polyurethane based product containing 7000 ppm fluoride from difluorosilane. It is dispensed in 1ml ampoules each ampoule containing 6.21mg of fluoride.  CAREX: It has low fluoride concentration than duraphat & has equal efficacy to that of duraphat as caries preventive agent
  • 26.
    TOPICAL FLUORIDES USEDIN PREVENTIVE DENTISTRY:  SODIUM FLUORIDE  STANNOUS FLUORIDE  ACIDULATED PHOSPHATE FLUORIDE  AMINE FLUORIDE 1) NEUTRAL SODIUM FLUORIDE (NaF)  Fluoride concentration - 9200ppm  A minimum of four applications with a 2% NaF solution gives a caries reduction of about 30%  METHOD OF PREPARATION  It is prepared by dissolving 20 gms of NaF powder in 1L of distilled water in a plastic bottle
  • 27.
     TECHNIQUE -KNUTSON’S TECHNIQUE  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.
  • 28.
     MECHANISM OFACTION :  When NaF is applied on tooth surface it reacts with hydroxyapatite crystals in enamel to form Calcium fluoride (CaF2) which is the dominant product of the reaction  As thick layer of CaF2 forms, it interferes with further diffusion of fluoride from the topical fluoride solution to react with hydroxyapatite and blocks further entry of fluoride ions. This sudden stop of the entry of fluoride is termed as ‘chocking off effect’  CaF2 acts as a reservoir and fluoride slowly leeches out of it  The CaF2 formed reacts with hydroxyapatite fluoridated hydroxyapatite increases the concentration of fluoride on enamel surface prevents caries
  • 29.
     ADVANTAGES : 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 intervals.  DISADVANTAGES:  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 time.
  • 30.
    2) STANNOUS FLUORIDE(SnF2)  Fluoride concentration-19500ppm  Stannous fluoride has been used at 8% and 10% concentrations  METHOD OF PREPARATION:  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.
  • 31.
     TECHNIQUE -MUHLER’S TECHNIQUE  Each tooth surface is cleaned with pumice or other dental cleaning agent for 5 to 10 seconds;  Unwaxed dental floss is passed between the interproximal areas;  Teeth are isolated and dried with air;  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 caries.
  • 32.
     MECHANISM OFACTION:  When SnF2 is applied in low concentration tinhydroxyapatite, which gets dissolved in oral tissues  At very high concentration Ca trifluorostannate forms along with tin tri-fluorophosphate  Tin trifluorophosphate is responsible for making the tooth structure more stable and less susceptible to decay  CaF2 is the end product both at low and high concentration which reacts with hydroxyapatite and a small fraction of fluorhydroxyapatite also gets formed
  • 33.
     ADVANTAGES : Using an 8% stannous fluoride solution at 6 to 12 months intervals conforms to the practicing dentist’s usual patient – recall system;  Administrative difficulties are avoided.  DISADVANTAGES :  In aqueous solution the material is not stable;  8% solution is quite astringent and disagreeable in taste, its application is unpleasant;  The solution occasionally causes a reversible tissue irritation manifested by gingival blanching;  Causes pigmentation of teeth which has a characteristic light brown colour
  • 34.
    3) ACIDULATED PHOSPHATEFLUORIDE (APF)  Fluoride concentration-12300 ppm  METHOD OF PREPARATION An aqueous solution is 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 solution For the preparation of acidulated phosphate fluoride gel, a gelling agent methylcellulose or hydroxyethyl cellulose is added to the solution.
  • 35.
     TECHNIQUE  APFis recommended for application at 6 or 12 months interval  Oral prophylaxis is done  Teeth to be treated are completely isolated and thoroughly dried with air  Application of gel is done using trays; disposable foam lined trays are preferred  It is reapplied every 15-30sec so as to keep the teeth moist with the fluoride solution throughout the four min period  The patient is instructed to eat, drink or rinse his mouth for atleast 30 min
  • 36.
  • 37.
     MECHANISM OFACTION  When APF is applied to teeth it initially leads to dehydration and shrinkage in the vol of hydroxyapatite crystals which on hydrolysis forms an intermediate product called Dicalcium phosphate dihydrate(DCPD)  DCPD is highly reactive and starts forming immediately after APF is applied  Fluoride penetrates into the crystals more deeply through the openings produced by shrinkage and forms fluorapatite  For the conversion of whole DCPD formed into fluorapatite, a deeper penetration and continuous supply of fluoride is required. Because of this reason APF is applied every 30 sec and the teeth have to be kept wet for 4 min
  • 38.
     ADVANTAGES  Requiresonly 2 application in a year;  The gel preparation can be self applied and thus the cost of application also gets reduced;  It has the ability to deposit fluoride in enamel to a deeper depth;  DISADVANTAGES :  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.
  • 39.
    4) AMINE FLUORIDE They are cariostatic agents  Some of them are surface active agents i.e. they have an affinity for enamel and thus will hold the fluoride for a longer time against the tooth  They also have anti bacterial properties. Reduced plaque formation and anti glycolytic activity is also reported with these compounds  Amine fluorides have been tested in dentifrices, mouthrinses and topical gels where they are either brushed on teeth or applied with a tray but it is not known if they are superior to the other currently available fluoride agents
  • 40.
    Characteristics Sodium fluorideStannous fluoride Apf Percentage 2% 8% 1.23% Fluoride concentration (ppm) 9200 19500 12300 ph neutral 2.4-2.8 3.0 Frequency of application 4 at weekly intervals 3,7,11 & 13 yrs biannually biannually Adverse effects no Tooth pigmentation Gingival irritation no Caries reduction 30% 32% 28%
  • 41.
    RECOMMENDATIONS FOR TOPICAL APPLICATION No more than 2 g of gel per tray or approximately 40% of tray capacity.  Pt. may have the need to swallow during the 4min procedure, saliva ejector is recommended.  After the procedure the pt. be instructed to expectorate thorougly for from 30sec to 1min.
  • 42.
    SELF APPLIED TOPICAL FLUORIDES Dentifrices  Mouth rinses  Gels  DENTIFRICES  The first clinical trial of fluoride dentifrice was initiated by Bibby in 1942  The various compounds used in dentifrice are sodium fluoride, stannous fluoride, monofluorophosphate and amine fluoride  A 200g tube of Colgate contains 1000ppm of fluoride with the fluoride compound as Monofluorophosphate
  • 43.
     A singlebrushing with a full ribbon of paste on a brush head provides about one gram of toothpaste and will expose the individual to approximately 1mgF  For young children non fluoridated and non abrasive toothpaste is recommended till the child is 4 years of age  After 6 years of age fluoridated toothpaste should be used  The amount should be pea sized and the paste should be pressed into the bristles and not on top of the brush
  • 44.
     MOUTHRINSES  Fluoridemouthrinsing is one of the most widely used caries preventive public health methods  Caries preventive agents used are Neutral sodium fluoride, Acidulated phosphate fluoride and Stannous fluoride
  • 45.
     Sodium fluoridemouthrinses  Formulated at concentrations of 0.2%(900 ppm F) for weekly use 0.05%(225 ppm F) for daily use  These are used by forcefully swishing 10ml of the liquid around the mouth for 60 sec before expectorating it  Recommendations for fluoride mouthrinses  Rinse and expectorate technique used for patients in fluoride deficient communities  In patients with increased caries risk e.g. those undergoing orthodontic treatment or radiotherapy
  • 46.
     FLUORIDE GELS Fluoride gel products include neutral sodium fluoride and acidulated phosphate fluoride with a fluoride concentration of 5000 ppm and stannous fluoride with a concentration of 1000 ppm  The gels are either applied in trays or brushed on teeth  Professionally applied – given twice a year  Self applied – once a day or more  Home fluoride gels are not recommended for children below 6 yrs and younger
  • 47.
    Limitations of fluoridegels  They violate the principle of delivering low concentration of fluoride at regular intervals  Toxicity hazard  Tedious to use on daily basis
  • 48.
    Conclusion  Fluoridation isuniversally accepted by the dentists and other medical professionals as being useful in preventing tooth decay  They can be used in areas where there are no central water supplies, where the fluoride conc. of well water is low  Topically applied fluoride has more effect compared to systemic fluorides  Topical fluorides are more economical.  But cannot be done on a large basis