FLUORIDES IN DENTISTRY
PRESENTED BY
NADIA IRSHAD
MDS 3rd year
PAEDODONTICS and Preventive Dentistry

Fluorides in Dental Tissues: Caries
Prevention and Fluorosis
AUTHOR : Michel Goldberg
Goldberg M (2020) Fluorides in Dental Tissues: Caries Prevention and Fluorosis.
JSM Dent 8(1): 1123

CONTENTS
 Introduction
 The element Fluoride chemistry and occurrence
 Total intake of fluoride
 From Air
 From Water
 From Food
 Historical evolution of fluorides
 Fluoride metabolism and bioavailability
 Physiologic distribution of fluoride
 In blood and soft tissue
 In hard tissue

 Excretion of fluoride
 Water fluoridation
 School water fluoridation
 Fluoride tablets
 Fluoridated salt
 Fluoridated milk
 Fluoridated flour and sugar
 Professionally aaplied fluorides
 Self appied fluorides
 Toxicity of fluoride
 Defluoridation
 conclusion

INTRODUCTION
⦁ Dental caries is a major dental disease affecting a large proportion of the inhabitants
of the world.
⦁ It impairs the quality of life for many people causing pain and discomfort.
⦁ Its very high morbidity potential has brought this disease into the main focus of
dental health professionals.

THE ELEMENT FLUORIDE CHEMISTRY &
OCCURRENCE
 -The Federal Register of United States Food and Drug Administration describes
fluoride as an essential nutrient.
 -The WHO expert committee on trace elements included fluorine as one of the 14
physiologically essential elements.
 -These essential elements are required for the normal growth and development of
Human Beings.

 Greek “floris”- destruction
 Latin “fluor”- flow or flux
 Symbol- “F”
 Atomic no.- 9
 Atomic weight- 18.99
 It is a pale yellow, corrosive gas, which reacts with practically all
organic and inorganic substances
 Most electronegative of all elements

 Most electronegative of all elements
 Small size of atom
 High electron affinity

 17th in order of abundance of all elements
 Constitutes about 0.032% in earth’s crust
 Fluoride containing minerals-
 Fluorspar (CaF2) - 48.8%
 Cryolite (Na3AlF6) – rare
 Fluorapetite Ca10(PO4)6F2- 3.8%
WHO Expert Committee on Oral Health Status & Fluoride Use
Geneva, 22-28 November,1993

 Fluoride in Air-
 HF or Gaseous F2
 Dust of f2 containing soils, gaseous industrial, coal smoke,
and volcanic emulsion.
 Fluoride in plants-
 Roots form soil and Leaves form air
 Indian Tea leaves – 70 to 375 ppm
 Vegetables- factories- 10ppm
 Fruits and vegetables- 0.2 to 0.5gm

 Fluoride in animal products-
 Beef, pork and mutton-0.3ppm
 Higher in Chicken- contamination bone and cartilage fragments
 Fish products- up to 20ppm
 Dried sea foods also fluoride rich 84.5ppm (South East Asia)
 Fluoride in beverages-
 Ranges from 0.05 to 1.05 ppm
 Fluoride content in alcoholic beverages generally reflects that of
water used.

Fluoride from Air
 Minimal
Fluoride from Water
 Most important single source of fluoride
 Dependent on fluoride concentration and amount
 Fluctuation –climatic and geographical areas
Fluoride from food
 0.3 to 0.6 mg/day
 Breast fed infant receives 0.003 to 0.004mg/day- formula fed infants
(1.2ppm) fluoride intake increased 50 times

 Excessive consumption of tea and sea foods- increased fluoride
 National Research Council 1980 – safe and adequate
1.5 to 4.0 mg/day in adults
0.05 to 0.07 mg/day in children for optimal dental health
Threshold level drinking water 2.0ppm- dental fluorosis

⦁ The history of fluoride is more than 100 years
old. The first hint of possible connection of
fluoride and dental health was given by:
SIR JAMES CRICHTON BROWNE in 1802.
He emphasized the importance of fluoride

⦁ 1901- DR. FREDRICK McKAY
Permanent stains present on the teeth of local inhibitants of
Colarado Spring, U.S.A. known as COLARADO STAINS
noticed. He called the stain Mottled Enamel
⦁ 1902- DR. J.M. EAGER
described similar stains present on teeth of certain italian
emigrants embarking at Naples as “ denti di chiaie.
⦁ 1916, Dr Green Vardmin Black
supported MCKay work with histologic evidence reporting it
as “an endemic imperfection of the enamel of the teeth

⦁ 1925,Dr F McKay change of water supply from spring
water of the Great Salt Lake of Oakely, Idaho City, showed
no brown stains in children.
⦁ 1928,Dr McKay and Gromer Kempt
Similar observation found in Bauxite where changed water
supply from a shallow well to foot well resulted in children
with badly stained teeth.
⦁ 1931,Mr HV Churchill -A spectrographic analysis of
Bauxite city water showed the presence of fluoride at the
level of 13.7ppm.

⦁ 1933,Dr H Trendley Dean
Shoe Leather Survey
⦁ 1939,Dean and McKay -
Came out with the most conclusive and direct proof that
fluoride in domestic water is primary cause of human
mottled enamel.
-
⦁ 1939,Dr H Trendley Dean -
Hypothesis showing the inverse relationship between
endemic dental fluorosis and dental caries emerged with
survey of four illinois cities.
In the same year- hypothesis showing ‘inverse relationship
between endemic fluorosis and dental caries’

Fluoride metabolism
⦁ Major route of the fluoride absorption is ingestion via the GIT.
⦁ The fluoride source may be organic and inorganic.
⦁ Fluoride is generally ingested in a beverage, in food or as a pharmaceutical
preparation such as NaF tablets.
⦁ The principal source of Fluoride ingestion is WATER.

After ingestion of fluoride , such as drinking a glass of
optimally fluoridated water
Majority is absorbed from stomach and small intestines
Into the blood stream causing short term increase in level of
blood within 20-30 minutes
This conc. declines rapidly within 3-6 hours.

EXCRETION OF FLUORIDE
⦁ Fluoride is excreted in urine and feces and lost through sweat.it occurs in traces in
milk, saliva, hair and tears.
⦁ Principal route of fluoride excretion is via the URINE .
⦁ Kidney is the main pathway of fluoride excretion with an average fluoride intake of
3.9mg/day

⦁ Fejerskov et al 1981 only children benefit from Fluoride incorporate into forming
Tooth enamel before eruption helps to prevent later decay, Presence of Fluoride at the
surfaces of teeth after eruption has been shown to be equal importance.
⦁ Hopcraft et al 2006- Fluoride prevent dental caries on both smooth surfaces and
occlusal surfaces of teeth. Water fluoridation reduces caries by approximately 38% on
approximal surfaces and 26% on occlusal surfaces.

⦁ Singh et al 2007- timing of exposure of Fluoride is also important, with
exposure during crown completion being effective irrespective of exposure at
maturation and post eruption.
⦁ Spencer et al 2008 Children living in non fluoridated areas take fluoride supplements in
the form of tablets, drops, chewable lozenges. However evidence suggests that
supplements increase the risk factor for dental fluorosis.
⦁ Rolla et al 1990- post eruptively, Fluoride affects plaque and saliva.Acid produced by
acidogenic bacteria releases fluoride from the dental plaque, which is then taken up by
demineralised enamel to form a more stable enamel structure.

Physiologic Distribution of fluoride
Fluoride in Blood:-
 Blood plasma is most reliable indicator
 ¾ in plasma and ¼ in RBC
 Fluoride exists in both forms
-bounded from
-ionic form- varies concentration F in drinking water
 Increase in plasma F with age and in presence of renal failure
Drinking water 0.25 or 1.25 ppm –plasma level 0.01 or 0.025ppm
Increased reactive sites and voids in old bone is more saturated and filled with F than
young bone

Fluoride in soft tissue:-
 Tissue/ plasma ratio = 0.4 to 1
 Ectopic calcification loci- F accumulation in Aorta,
tendon, cartilage and placenta

Effects on kidney
 Fluoride is normally cleared from the blood by deposition in bone,
excretion in urine- unable to find toxic effect on kidney endemic
fluorosis.
 Patients with chronic renal failure- dialysed with fluoridated have
additional load of fluoride
So fluoride free water is used for kidney dialysis

Fluoride in hard tissue
Bone:-
 Total amount-2.6mg
 Most of F in the body retained in the skeleton-vary according to the renal
clearance
 F enter in mineralized tissue-replacing 0H-, C03
2-
 Remodeling bones deposit more fluoride than older people
 Fluoride deposition is a reversible process

Teeth:-
 Deposition occurs in successive stages.
Initial deposition – organic and mineral phases are laid down
Pre-eruptive maturation phase-before eruption
Post eruptive maturation and aging period
 Dentine contains 4 times more than enamel
 Fluoride concentration not uniform
 Fluoride concentration –initial stages is higher than on completion
(mineralization process- release of F to the bathing fluid)
 Primary teeth less fluoride concentration than permanent teeth

 Fluoride concentration in the outer enamel (2micrometer)-
1700ppm-non fluoridated areas (0.1ppm)
2200 to 3200ppm- optimally fluoridated areas (1ppm)
4800ppm- 5 to 7ppm
 Depth 5 micrometer-
Permanent teeth Primaryteeth
Non-fluoridated areas
Fluoridated areas
1100ppm
2200ppm
670ppm
950ppm

 F concentration in newly erupted teeth- higher in
in incisal than cervical margin
 Diffusion of F in enamel NaF and
monoflurophosphate(100pmm)-
10-9cm2/sec
 Speed at which F penetrates in enamel-
38 micrometer/ hour (186micrometer/ day)

Concentration in dentin:-
more than enamel-apatite crystals are smaller
-surface area and capacity to take is much larger
In permanent teeth:
Highest near the pulpal surface
low in secondary dentin
In primary teeth
complicated –physiologic resorption occurs towards pulpal side
greatest rise and fall – Pulpal surface of multirooted teeth

Fluoride concentration in Cementum:-
 Higher than any skeleton or dental tissue
 Tissue is very thin
 Near the tissue surface- accessible to fluoride present in blood
 Increases with age

Placental transfer of fluoride
 Fluoride in primary teeth and
bones: placental transfer
 Placenta does not selectively
inhibit fluoride transfer
 Higher the fluoride ingestion:
partial barrier may exist

MECHANISM OF ACTION
•Increase enamel resistance/ Reduction enamel solubility
•Increased rate of post eruptive maturation
•Remineralisation of incipient lesions
•Interference with plaque microorganisms
•Modification in tooth morphology

CHEMICAL STRUCTURE OF ENAMEL
38

CHEMICAL STRUCTURE OF ENAMEL
39

UNIT CELL OF
HYDROXYAPATITE
PHOSPHATE
40
CALCIUM
HYDROXYL ION
Ca10 (PO4)6 (OH)2

MAGNESIUM
FLUORIDE
CARBONATES
41

• Carbonate substitute for
phosphate
CARBONATES
• Magnesium substitute for
calcium
MAGNESIUM
• Fluoride substitute for
hydroxyl ion
FLUORIDES
42

DISRUPTIVE FOR CRYSTAL STRUCTURE
LESS STABLE
MORE SOLUBLE IN ACIDS
43
MAGNESIUM
AND
CARBONATES

17
HYDROXYAPATITE CRYSTALSHOWING REPLACEMENT OF ONE HYDROXYLBYA
FLUORIDE ION
FLUORIDE
HYDROXYL COLUMN

Newly
erupted
tooth
Matured tooth
Matured tooth
With fluoride
Enamel structure
(carbonated apatite- more
soluble in acid)
Hydroxyapatite
(less soluble in acid)
Fluorapatite
(least soluble in acid)
Fluoride
uptake
FIRMLY
BOUND
45
DIFFERENT LEVELS OF ENAMEL SOLUBILITY IN ACIDS

Ca10 (PO4)6 (OH)2 + 2F -
(HYDROXYAPATITE)
Ca10 (PO4)6 F2 + 2OH –
(FLUOROAPATITE)
LOW CONCENTRATION OF FLUORIDE
Hydroxyapatite
+
Low concentration of Fluoride [Systemic fluorides]
Fluorhydroxyapatite
+
Fluoride Fluorapatite
46

Hydroxyapatite + high conc. of fluoride [Topical fluorides]
CaF2 + Po4 + Hydroxyapatite
HIGH CONCENTRATION OF FLUORIDE
Hydroxyapatite + CaF2
Fluoridated hydroxyapatite ( FHA)
Fluorapatite
Repeated exposure to
fluoride over long
period of time
CaF2 Ca++ and F
F-
+
LOOSELY BOUND
FLUORIDE
20

Ca10 (PO4)6 (OH)2 + 20F -
(Hydroxyapatite)
10CaF2 + 4PO4
3- + 2OH –
(calcium fluoride)
48

CRITICAL PH
49
The critical pH is the pH at which saliva and plaque fluid
cease to be saturated with calcium and phosphate, thereby
permitting the hydroxyapatite in dental enamel to dissolve
Critical pH for
Hydroxyapatite is around 5.5
Fluorhydroxyapatite is around 4.5

• Enamel exposed to a pH
• Ca10(PO4)2(OH)2 + 8H+
5.5 or lower, it will dissolve
10 Ca++ + 6HPO- + 2H2O
The Stephan Curve
50

• concentration of calcium, phosphate and other ions in the
solution
• Plaque stops producing acid pH rises and precipitation
of mineral
• cyclic phenomenon
51

FLUORIDE IN
PLAQUE FLUID
A
C
I
D
I
C
E
N
V
I
R
O
N
M
E
N
T
PENETRATE AT THE
SUBSURFACE
ADSORB TO THE CRYSTAL
SURFACE
PROTECTS CRYSTALS FROM
DISSOLUTION
52
ACIDS

• Hypo mineralized areas ( very common in newly erupted teeth:
prone to dental caries)
• Fluoride RATE OF MINERALIZATION
• Post-eruptive maturation and
similar process but maturation occurs in
remineralisation are
hypo
mineralized areas while remineralisation occurs in
demineralised areas ( incipient caries)

54

FLUORIDE
HIGH CONCENTRATION
55
LOW CONCENTRATION
BACTERICIDAL BACTERIOSTATIC

ENOLASE PHOSPHATASES CATION
TRANSPORT
FLUORIDE INHIBITS
57

FLUORIDE INGESTED DURING
TOOTH DEVELOPMENT
SHALLOW FISSURES
SMALLER CUSP TIPS

Fluoride supplementation
Systemic Topical
Dietary fluorides
Salt fluoride
Fluoride in sugar
Water fluoridation
School water fluoridation
Milk fluoridation
Professional application
Self
application

Water fluoridation
Definitions:-
 ‘Water fluoridation is defined as controlled adjustment of the
concentration of fluoride in a communal water supply so as to maximum
caries reduction and a clinically insignificant level of fluorosis.’
 Defined as’ upward adjustment of the concentration of fluoride ion in a
public water supply in such way that the concentration of fluoride in the
water may be consistently maintained at 1 ppm by weight to prevent
dental caries with minimum possibility of causing dental fluorosis’

Water fluoridation…
 First began in Grand Rapids, U. S. A., in 1945
Studiesonwaterfluoridation(city) Control
1. GrandRapids(Michigan)
2. Newyork
3. Brantford(Ontario-Canada)
4. Evanston(Illinois)
5. Teil (Netherlands)
Muskegon
Kingston
Sarnia
Oak-Park
Culemberg
After 1o years -DMFT of fluoridated cities 60% lower than the control cities

 Murray and Rugg-gunn
 compiled the status of water fluoridation globally
 using over 90 studies he compared cariostatic benefits in primary and permanent
dentition.
 Early 1960’s successful water fluoridation program –in Singapore and
Hongkong
 Backer Dricks conformed caries protection….
 Buccal, lingual and gingival smooth surface- 85%
 Interproximal surface- 75%
 Pit & fissure and occlusal surfaces- 35%
 First study on deciduous dentition in UK by Weaver in North and South Sheilds
(41%)

 Acc to Connet, Beck, Micklem (2010) the Fluoride used for water fluoridation of drinking water it is
not considered as a nutrient but a drug instead.
 Paul Connet (2012) points out the fact that fluoride acts topically and not by systematical
accumulation, so the original reason for fluoride ingesting has disappeared.
 Gray(2008) author of book DRINKING WATER QUALITY highlights children water consumption over
the past 20 yrs from 1.4litres/day replaced by acidic sugar base drinks. So original purpose of fluoridating
water has become redundant.

⦁ 1944-1959 FrancisArnold, Philip Jay and John Knutson
-GRAND RAPIDS MUSKEGON STUDY.
⦁ 1945-1955 David et al
NEWBURGH- KINGSTON STUDY 10 year study.
-
⦁ 1967(1946-1960) Dr JR Blayney, TN Hill, Zimmerman
EVANSTON OAK PARK STUDY .

⦁ 1951 Hutton et al and 1965 Brown and Poplove-
CANADIAN STUDY
⦁ 1961, Backer Dirks et al -DUTCH STUDY (Tiel-
Culemborg
⦁ 1965, Ludwig - NEW ZEALAND STUDY.

 Fluoride compounds used in water fluoridation-
 Fluorospar
 Sodium fluoride- most expensive source
 Silicofluoride
 Sodium silicofluoride- cheapest form
 Hydrofluorosilicic acid
 Amonium silicofluoride
 Types of equipments for water fluoridation-
 Saturation system- 4% NaF (recommended for small towns)
 Dry feeder system-NaF or silicofluoride (medium sized towns)
 Solution feeder- Hydrofluosilicic acid (large towns)

Optimal fluoride concentrations and climatic condition
 In Temperate climates (formative stages) - 1ppm
 Children living in this area- 1mg/daily
 Galagan and Vermillion emperical formula:
Based on daily fluid intake, body wt and temp
ppm F =0.34/E E = -0.038+0.0062 t
E -daily water intake
t- max daily temp in degrees Fahrenheit
WHO recommended (1994)- 0.5 to 1.0 ppm

 Simple modified method to determine opt fluoride
concentration and mean annual temp… Richard etall
oC oF Recommended
ppm
<18.3
18.9-26.6
>26.7
<64.9
66.0-79.9
>80.1
1.1- 1.3
0.8- 1.0
0.5- 0.7
In addition to climatic condition total fluoride intake from sources
otherthan water..
Reasonable goal 60 to 65% caries reduction without fluorosis

Water fluoridation…
Benefits:-
 Both pre eruptive and post eruptive effects
 Topical effect through release in saliva
 Least expensive and most effective
 “Halo effect” or “Diffusion”
Feasibility in INDIA
 Ground water btw 1 and 5mg/ml.. (21mg/ml)
 Ministry of Health Govt of India prescribed 1.0mg/ml and 2mg/ml
 1983 Nanoti & 1988 Nawlakhe given Indian standard specification desirable limit
as 0.6 – 1.2 mg/ml
 Short coming- only implemented only in areas have central pipe water supply
system.
 Only 30% of population have piped water supply

School water fluoridation
 Suitable alternative –b’cos f consumed during school days
 4.5 to 6.3 ppm- no fluorosis
 Caries reduction 45 to 50%
 Venturi system is most suitable- almost no maintainance
Advantages:-
 Effective public health measure-water supply is not possible
Disadvantages:-
 5 to 6 years old upon starting school- will not provide preeruptive contact..
 Intermittent fluoride exposure-less than 180 days in a year

Fluoride tablets
Provides systemic effect before mineralization and topical effect
after..
In deciduous dentition:-
 Caries reduction 50 -80%, started before2 years continued of 3-4
years
 Hoskova 1968(4 years)
- fluoride tab started prenatally-93%
- since birth- 54%
In permanent dentition:-
 20 to 40% caries reduction
 Longest clinical trial carried out by Aasenden and Peebles-0.5mg
F tab below 3years and 1mg thereafter—followed by 8-11 years

Fluoride tablets…
 Fluoride level in surface enamel (1-2micrometer)
 Increased to 3000ppm
 Fluoridated water- 2300ppm
 Non fluoridated water- 1800ppm
 0.5mgF/day –upper limit desirable level first year of life
 Concluding that fluoride supplements during developing dentitions results in
caries reduction than water fluoridation
Recommended dietary fluoride supplements (1999)
Age in years Concentration offluoride in drinking water ppm
< 0.3ppm 0.3 to0.6ppm >0.6ppm
Birth to6 years None None None
6 months-3 year 0.25mg/day None None
3 to6 years 0.5 mg/day None None
6 to16 years 1.0mg/day None None

Fluoride tablets…
Commercially available NaF (fluoraday, tymaflour and luride)
 2.2 mg NaF- 1mg of F
 1.1 mg NaF -0.5mg of F
 0.55 mg NaF – 0.25mg of F
 Neuromuscular coordination not fully developed until 16- 18 weeks
-up to 2 years drops are preferable
 Daily recommended dose:-
 Below 2 years – 0.5mg
 2 to 3 years -0.5 to 0.7mg
 Above 3 years- 1 to 1.5mg
Fluoride tablets: topical caries preventive agent to be used as Dental Public
Health Measure in Rural India

Fluoride tablets…
To enhance cariostatic effect-
 Chew and suck the tab
 Preferably at bed time..
 Continued at least until 12 to 14 years
 Should not given –water supply exceed 0.7ppm
 Should not given with milk and milk products
 Cannot replace water fluoridation –parents fail to comply with the regimen

Salt fluoridation
 Fluoridated salt in Switzerland for the first time in 1955 (90ppm)
 90ppm -20 to 25% caries reduction
 Optimum level of fluoride in salt –Toth suggested
 Urinary fluoride excretion from salt should be similar to that obtained from
fluoridated drinking water
 200 to 350 ppm salt- 0.85 and 1.05 similar to populations ingested fluoridated
water for 10 years.
 250ppm did not achieve cariostatic effect – optimal fl content water

Salt
fluoridation…
Advantages:-
 Low cost
 Negligible waste
 Ease of implementation
 Free choice for individual households
Disadvantages:-
 Fluoride dosages of different age in different regions
 Lower salt consumption during tooth forming years

Salt fluoridation…
Feasibility in India:-
 Viable and feasible method
Easily monitored
Effective control- supply
Individual monitoring not required
Freely available
Readily acceptable- does not alter the
colour

Milk fluoridation
 First mentioned by Ziegler in 1956
 Stephen et al –daily ingestion of 200ml (7ppm) for 4 years, 38.8% reduction
( 1st permanent molar)
 Hellestrom and Ericsson—fluoride uptake by enamel from salt is greater..
Advantages:-
 Need to drink under 14 years of age
Disadvantages:-
 Incompletely ionized in milk
 Lower absorption from milk than water
 Variation in intake
MILK
FLUORIDATION

Milk fluoridation…
 Requires parental or school efforts
 Technical difficulties
 Problem in distribution
 High cost
Feasibility in India:-
 Binding with calcium and protein in milk
 Not seem to viable and feasible
 Cannot afford milk daily
 No central milk supply system
 Variation in intake and quantity of milk

Fluoridation of flour and sugar
 Advantages requiring much less of chemical
 Fluoridation of sugar has adv –combining the culprit and cure (difficulty
to provide proper dosage)
 The effects of fluoridating the water can extend to communities
without a fluoridated water supply through a phenomenon known as
the 'halo effect. ' This effect occurs when food and beverages prepared
with fluoridated water are consumed in non-fluoridated communities,
sharing the benefits of their fluoridated water.

Exception to school water fluoridation, salt fluoridation most
promising alternative to water fluoridation.
Method Average % cariesreduction
ofdentalcaries
Community water fluoridation
School water fluoridation
Dietary fluoride supplementation
50 to 65%
40%
50 to 65%

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.

SODIUM FLUORIDE(NaF)
- Neutral ph, 9200 ppm
-1941 Bibby, 1942 Knutson,
-1948 Knutson & Fedelman
• Method of Preparation:-
20 gm in 1 liter of distilled water
• Technique of application
(Knutson & Fedelman tech 1948).
- four appointmets
- quardrant/half mouth, isolated
- applicator sticks, dried 3-4 mins
- procedure repeated
20gms
1 L

 Mechanism of action :-
Ca10 (PO4)6 (OH)2 + 20 F-  10 CaF2 + 6PO4
-3 + 2(OH)-
“CHOKING OFF EFFECT”
CaF2 + 2Ca5 (PO4)3 OH  2Ca5 (PO4) 3F + Ca (OH)2
Advantages:-
• Chemically stable
• Taste accepted
• Non irritating
• No discoloration
• Public health programs … multiple chair procedure
Disadvantages:-
• Four visits short time
• John E. Butts 1966 in journal of public health dentistry
• Sodium fluoride has been shown to be safe and effective as an agent for
fluoridization; Virtually all researchers agree that approximately a 40 percent
reduction in new carious lesions may be expected from the application of sodium fh-
ride to the teeth of children who live in nonfluoride areas;

STANNOUS FLUORIDE
1957 Muhler & Dudding
Method of Preparation:-
0.8 gms powdered in 10 ml of distilled
Water
Technique of application
(Muhler Tech)
 Teeth cleaned,isolated
Paint on technique
Repeat every 6 months
 Ref: MS Muthu, Pediatric dentistry principles and practice, 2nd edition,2011; pg:155-159,
Elsevier publication.
 Ref: J.J.Murray, Fluorides in caries prevention, 3rd edition, 1999; pg:179-207,Butterwort2h0-
0.8 gm
10L

Mechanism of action :-
•At low concentrations
Ca5 (PO4)3 OH + 2SnF2  2CaF2 + Sn2 (OH)PO4 + Ca3(PO4)2
• At high concentration is:
Ca5 (PO4)3 OH + 16 SnF2  CaF2 + 2Sn3F3PO4 + Sn2 (OH)PO4 + 4 Ca (SnF3)2
2Ca5(PO4) 3OH + CaF2  2 Ca5 (PO4) 3F + Ca (OH)2
• Advantages:-
- conforms to the dentist’s recall system
- administrative difficulties are avoided
• Disadvantages:-
- material not stable
- unpleasant taste
- tissue irritation
- teeth pigmentation
 ML Baker et al. 2013. Journal of clinical dentistry
 When properly formulated into commercially available dentrifrices , stabilizes
SnF2 provides greater level of enamel protection from citric acid ersion than
either NaF or Sodium MFP.

ACIDULATED PHOSPHATE FLUORIDE
 Brudevold et al developed APF formula in 1960s
Method of application
Solution Gel
Method of preparation
Foam
•20gms of sodium fluoride in 1l of 0.1M
phosphoric acid +50% hydrofluoric acid-
Brudevolds solution
• for gel methylcellulose or hydroxyethyl
Cellulose
Acqueous – paint on
Gel – tray technique
Foam –tray technique
•Sit upright
•Oral prophylaxis,isolated
•Foam trays , <5ml
•Tray placed,saliva ejector
•Pressure buccal and lingual, 4 mins
•Not eat,drink 30 mins

Mechanism of action :-
dehydration of hydroxypatite crystals.
Shrinkage of volume of hydroxyapatite crystals
Formation of dicalcium phosphate dihydrate (DCPD)
Formation of fluorapatite
Ca5 (PO4)3 OH + 4 H+  5 Ca +2 + 3HPO4
-2 + H2O
Ca +2 + HPO4
-2 Ca. HPO4. 2H2O
5Ca. HPO4. 2H2O + F  Ca5 (PO4)3 F + 2HPO4
-
ADVANTAGES
• 2 applications
• Gel - self applied
•Deposit in greater
depth
•Stable
DISADVANTAGES
•Long application time
•Acidic, sour ,bitter
•Cannot be stored in glass containers

An in-vitro research by Song et al. found no significant
differences between APF gel and foam regarding the
amount of fluoride uptake into enamel. They stated that
foam could provide an effect similar to that of gel in
terms of dental caries prevention.

Comparison
Characterstics Sodium Flouride
(NaF)
Stannous Fluoride
(SnF2)
APF
Percentage 2% 8% 1.23%
Fluoride concn.(ppm) 9,200 19,500 12,300
pH Neutral (7) 2.4 - 2.8 3.0
Frequency of Application 4 at weelky intervals
3,7,11,13 yrs
Biannually Biannually
Adverse effect - Tooth pigmentation
Gingival irritation
-
Caries reduction 30% 32% 28%
Ref: MS Muthu, Pediatric dentistry principles and practice, 2nd edition,2011; pg:155-159,
Elsevier publication.
Ref: J.J.Murray, Fluorides in caries prevention, 3rd edition, 1999; pg:179-207,Butterwort2h8-

Fluoride varnish
 Discovered in Europe in 1960, Schmidt.
 Commercially available.
 Duraphat, fluorprotector, duraflor, carex
Technique of application:-
•Prophylaxis, teeth dried
•No cotton
•0.3-0.5ml…full dentition, tufted brush
•First lower then upper
•varnish …painted on the tooth surface
•4 mins ..spit
•Semisolid ,liquid diet…18 hours

Duraphat(1968).
 Heresel and Schmidt
 Sodium fluoride in varnish form  2.26mg F/ml suspended in an alcoholic solution of
natural organic varnishes,contains 22600ppm
 Hardens into yellowish brown coating in the presence of saliva
 Caries reduction – 30-40% in permanent, 7-44% in primary
 10Ca5(PO4)3 OH + 10F- 6Ca5(PO4) 3F + 2CaF2 + 6Ca3(PO4)2 + 10 OH-
CaF2 in low concentrations reacts with crystals of hydroxyapatite & forms fluorapatite.
2Ca5(PO4)3OH+ CaF2  2 Ca5(PO4)3F+ Ca(OH)2
Mechanism of action :-

• 2% Difluorosilane in a polyurethane-based lacquer.
• F content 7000ppm
• 1ml ampules, 6.21mg fluoride
• Efficacy 1-17%
R-SiF2OH + H2O  R-Si(OH)3 +2 HF
• Koritzer and Levy (1979) -fluorosilane enhance retention and penetration
of fluoride in enamel.
• Arends et al (1980)- fluorprotector penetrates the porosities of enamel.
• A.G. Dijkman et al (1983)- CaF2 in Duraphat specimens was lost within 1
week but in fluorprotector was noticeable upto 1 month.
Fluor protector: (1975)

Duraflor
 5% NaF,22.6F/ml
 Xylitol, improves taste
 Less viscous
CAREX:-
 contains a lower fluoride concentration [1.8% fluoride].
ADVANTAGES
•Prolonged contact time
•Slow-releasing reservoir
•Simplicity of its application
•Applied quickly and easily and sets rapidly on teeth
•Gagging and swallowing are unusual
DISADVANTAGE
Temporary discoloration

SELF APPLIED TOPICAL APPLICATIONS
RINSES
DENTRIFICES
CHEWING GUM
IMPREGNATED DENTAL FLOSS

FLUORIDE DENTIFRICE
1)SODIUM FLUORIDE /STANNOUS
FLUORIDE DENTRIFICES
•First trial, Bibby 1942 sodium fluoride,approved in 1973
•Rules …0.188to 0.254% with 650ppm F
•1954,clinical report stannous fluoride Muhler..1955 FDA recognized
•Although not used due to staining and metallic taste

Monoflourophosphate
dentifrice
• First commercial dentifrice to be . Insoluble metaphosphate as abrasive -
- 25% caries reduction
• MFP - compatible with other abrasives like calcium carbonate,etc
• Mechanism of action
Amine fluoride dentifrice
 Contains two amine fluorides with total fluoride conc of 1125 ppm with
an insoluble sodium metaphosphate as the abrasive.
 Elmex …..Marketed in 1963 in Switzerland.
PO3F + OH = PO4 + F + H

 B. Aishwarya Reddy, et al in 2019: Prevalence of toothpaste swallowing habit
in children between the age group of 3 and 5 years
An online questionnaire was prepared using SurveyPlanet and was circulated
among 75 parents of children between the age group of 3 and 5 years having
toothpaste swallowing habit.
Results: About 96% of the children had the habit of toothpaste swallowing.
Intestinal problems were seen in more children and also few children’s complaint
about stomach pain.

Fluoridated toothpicks
& dental floss
 For proximal areas of the teeth.
 Toothpicks are impregnated with sodium fluoride.
 Toothpicks (0.1-0.2 mg /pick).
 Flosses (0.3mg F/gm).
Fluoridated chewing gums
 Recommended to high caries risk (xerostomia) persons.
 It stimulated saliva secretion.
 Fluoride range 0.2-0.3mg F/gm.

Fluoride Rinses
 These are for school based health programmes or
home.
 It contains NaF, APF & SnF.
 Reduce caries to 20-50%.

RECOMMENDATIONS(AAPD,2014)
 There is confirmation from evidence-based reviews that fluoride use for the prevention and
control of caries is both safe and highly effective in reducing dental caries prevalence.
 There is evidence from randomized clinical trials and evidence-based reviews that fluoride
dietary supplements are effective in reducing dental caries and should be considered for children
at caries risk who drink fluoride-deficient (less than 0.6 ppm) water.
 There is evidence from randomized controlled trials and meta-analyses that professionally
applied topical fluoride treatments as five percent NaF V or 1.23 per-cent F gel preparations are
efficacious in reducing caries in children at caries risk.
 There is evidence from meta-analyses that fluoridated toothpaste is effective in reducing dental
caries in children with the effect increased in children with higher baseline level of caries, higher
concentration of fluoride in the toothpaste, greater frequency in use, and supervision. Using no
more than a smear or rice-size amount of fluoridated toothpaste for children less than three
years of age may decrease risk of fluorosis. Using no more than a pea-size amount of fluoridated
toothpaste is appropriate for children aged three to six.
 There is evidence from randomized clinical trials that 0.2 percent NaF mouthrinse and 1.1
percent NaF brush-on gels/pastes also are effective in reducing dental caries in children.

Fluoride toxicity
Toxic effects of fluorides: Acute and chronic
Acute toxicity:
 Accidental contamination of food by NaF and NaSiF salts
Certainly Lethal Dose (CLD) 5 to 10 gm NaF
or
32 to 64 mgF/kg
Safely Tolerated dose (STD) ¼ CLD
1.25 to 2.5mg NaF
or
8 to 16 mgF/kg
Toprevent accidentalpoisoningofaninfantweighing (10kg)Council onDentalTherapeuticsof ADA
recommendedthat:nomorethan264mg ofNaF (120mg ofF) dispensedatone time

Acute Fluoride
toxicity…
Acute poisoning:
 Causes death by blocking normal cellular metabolism
 Inhibits enzymes causing vital functions-Initiation and transmission of nerve
impulses to cease
 Interferences with essential body functions controlled by calcium.
Common signs and symptoms of acute fluoride toxicity:
Lowdosages High dosages
Nausea
Vomiting
Hyper salivation
Abdominalpain
Diarrhea
Parathesia
Convulsions
Cardiac
Arrhythmias
Painfulspasms
Paresis

Acute Fluoride
toxicity…
 Death usually results: cardiac failure or respiratory failure
Serious symptoms : with in 1 to 2 hours after ingestion
Death occurs from 2 to 4 hours after ingestion
 Nausea and vomiting : dose 30 t0 80 mg of NaF
 Vomiting diarrhea and severe abdominal pain: 100mg NaF
 Gastrointestinal symptoms: corrosive effect on gastric mucosa by HF acid
Treatment : administration of calcium or magnesium or aluminum salts

Chronic toxicity
Fluoride level Waterconsumption Effects
0.7 to 1.2 ppm
1.5 to 3.0ppm
3.0 to 8.0ppm
8.0ppm or more
Depending ontemp of area
Period of 5 to 10 years
15 to 20 years
5 to 10 years
Prevents dental caries
Mild dental fluorosis
Severe dental fluorosis
Mild skeletal fluorosis
Severeform of dental
skeletal fluorosis

Dental Fluorosis
 Dental Fluorosis also termed as mottled enamel is an extremely
common disorder, characterized by hypomineralization of tooth
enamel caused by ingestion of excessive fluoride during enamel
formation.
 It is a cosmetic condition that occurs during first eight years
of life

⦿Excess fluoridation of
drinking water
⦿Ingestion of fluoride
toothpaste
⦿Overuse of Fluoride
tablets
⦿Consumption of processed
food made with fluoridated water

• Structurally, an increase in fluoride intake
results in an increase in degree and extent
of porosity of enamel.
• Enamel changes described may be a result
of fluoride damage of secretory
ameloblast.
• There can either be due to fluoride induce
change in compositon of enamel matrix or
be a result of disturbance of the cellular
processes during enamel maturation.

Chalk like discoloration of teeth with
white spot or lines on tooth enamel
In more severe cases, the affected area
have yellow or brown discoloration.
In extreme forms, fluorosis may result
in pitted tooth surface
Symptoms : Discolored tooth

1. Dean’s Fluorosis Index- 1934
2. Community Fluorosis Index-1946
3. Thylstrup-Fejerskov Index-1978
4. The Developmental Defects of Enamel Index-1982
5. Tooth Surface Index of Fluorosis -1984
Horowitz et al
6. Fluorosis Risk Index-1990 given by Pendrys
given by

MOTTLED ENAMEL
 It is a condition indicates the fluorosis characterized by minute white flecks
or yellow or brown spots or area scattered irregularly streaked over the
surface of tooth

It is score according to method described by Al Alousi et al as follows
⦿Type A : White area less than 2 mm
⦿Type B : White area more than 2 mm
⦿Type C : Brown area less than 2 mm
⦿Type D : Brown area more than 2 mm
⦿Type E : Horizontal white lines
⦿Type F : Horizontal brown lines

⦁ Introduced by Trendley H Dean in 1934.
⦁ It is also known as Dean’s Classification System for
Dental Fluorosis.
ORIGINAL CRITERIA( 1934)-
⦁ It was based on a 7- point ordinal scale: normal,
questionable, very mild, mild, moderate, moderately
severe, severe.

🞂 NORMAL:
Enamel is translucent, semi-vitriform type of structure.
Smooth, glossy surface usually of a pale creamy white colour.
🞂 QUESTIONABLE:
Slight aberrations, ranging from a few white flecks to occasional white spots.
1-2 mm in diameter.
🞂 VERY MILD:
 Small, opaque, paper-white areas scattered irregularly or streaked
on the labial and buccal surfaces
 Involves <25% of the tooth surface.
 Small pitted white areas are on the summits of the cusps.
 No brown stains present.
🞂 MILD:
White, opaque areas involve at least half of the tooth surface.
Surfaces of molars, bicuspids and cuspids show thin white layers worn off .
Bluish shades of underlying normal enamel.

🞂 MODERATE
:
No change in the form of tooth.All surfaces are involved.
Minute pitting on labial and buccal surfaces.
Brown stain is frequently a disfiguring complication.
🞂 MODERATELY SEVERE-
Greater depth of enamel is involved.
Asmoky white appearance is often noted.
Pitting is observed on all the tooth surface. Brown stain if present is generally
deeper in hue.
🞂 SEVERE-
Hypoplasia is marked.
Form of teeth is at times affected.
Often manifests in older children as a mild pathologic incisal-occlusal
abrasion.
Deeper pits and often confluent stains are widespread .
Range from chocolate brown to almost black in some cases.

Classification Description
Normal Smooth, Glossy, Pale, Creamy white translucent surface
Questionable Ranging from few white flecks to occassional white spot
Very mild Small opaque paper white area scattered over the
tooth but not involving as much as 25 % of tooth
surface
Mild The white opaque areas in the enamel of the tooth
are more extensive but do not involve as much as
50% of the tooth
Moderate All enamel surface of teeth are affected and the
surface subject to attrition show wear. Brown stain is
frequently a disfiguring feature
Severe All enamel surfaces are affected discrete or
confluent pitting . Brown stains are widespread and
teeth often present a corroded like appearance.
CLASSIFICATION OF DENTAL FLUOROSIS ( Deans Index)

Smooth, Glossy, Pale, Creamy white translucent surface

Ranging from few white flecks to
occassional white spot

Small opaque paper white area scattered
over the tooth but not involving as much
as 25 % of tooth surface

The white opaque areas in the enamel of the
tooth are more extensive but do not involve as
much as 50% of the tooth

All enamel surface of teeth are affected and
the surface subject to attrition show wear.
Brown stain is frequently a disfiguring feature

All enamel surfaces are affected discrete or
confluent pitting . Brown stains are widespread and
teeth often present a corroded like appearance.

⦁ The available data suggests that 15 states in INDIA are
endemic for Fluorosis(fluoride level in drinking water >1.5mg/l),
and 62 million people in INDIA suffer from dental, skeletal and non
skeletal fluorosis.
⦁ Out of these 6 million are children below the age of 14 years
⦁ Groundwater is considered as the major source of drinking water in
most places of earth.
Fluorosis in India Int j RES Dev Health
april2013;vol1(2)

Microabrasion : ( Conservative
removal of outer layer of enamel )
Followed by tooth whitening can make the
brown discoloration less apparent

⦿It coats the teeth with hard resin
that bonds to the enamel.

⦿These are the customized shells
that cover the front of teeth to
improve the appearance.

⦿ To prevent fluorosis , fluoridation of drinking water
should not exceed normal range
⦿ Normal range : 0.7 to 1.2 ppm
⦿ Fluoride supplement should only be prescribed for
children living in nonfluoridated
⦿ Use only acceptable amount of toothpaste for children
under 6 year ( pea size )
⦿ It is important to teach the child to spit out the
toothpaste after brushing instead of swallowing

FEATURES OF WHITE CARIOUS LESIONS
⦿ More defined shape
⦿ Well differentiated from surrounding enamel
⦿ Often located in the middle of the crown
⦿ Randomly distributed
⦿ If the growth stops brownish discoloration is seen which is
known as arrested caries.
FEATURES OF DENTAL FLUOROSIS
⦿ White/Yellowish lesion
⦿ Not well defined
⦿ They are visible without drying of teeth.
⦿ These usually have a smooth surface.
⦿ Symmetrically distributed

⦿A number of factors can lead to the
development of white spot on tooth
sometimes these spots are caused by
nutrition, genetics, or an excessive intake
of fluoride while other times they become
evident after braces have been removed.
⦿Usually white spots that appear on teeth
are actually areas of decalcified enamel
and sometimes this problem leads to the
deterioration of teeth

⦿ First evidence of tooth decay is a white spot
lesion and by this the tooth enamel has taken on
an opaque colour in the area where cavities begin
to form
⦿ White spot on the tooth can appear after the
changes have occurred in the mineral content of
teeth
⦿ White spot can appear in connection with
condition called fluorosis which results of
having excess intake of fluoride.
⦿ White spot lesion are also commonly attributed to
orthodontic braces

⦿TYPES OF WHITE CARIOUS LESIONS
Smooth surface caries
⦿They are defined as the caries present on
the proximal surfaces and along the gingival
1/3rd of the tooth surface.

Pit and Fissure caries
⦿ Pits are defined as small depressions
present along the terminal ends of the
development clefts.
⦿Fissures are defined as long clefts present
on the occlusal surface of molars and
premolars.

 ⦿ Patient with orthodontic braces have
difficulty in brushing their teeth and results
in build up of plaque
 ⦿The acid in the plaque can severely harm to the
enamel and eventually cause cavities.
 ⦿The first evidence of this type of tooth decay is
white decalcified enamel spot or lesion that
becomes apparent when braces are removed.

⦿ Fluoride treatment
 ⦿Bonding & Porcelain laminate placement depending on the severity of
the problem

DEFLUORIDATION
 Defluoridation means to improve the quality of water with high fluoride
concentration by adjusting the optimal level in drinking water
Absorption and ion exchange method:-
exchange negative ions such OH- group for fluoride ions depends up on PH,
temperature, flow rate, grain size of the material
common used materials: activated alumina, activated bauxite,
Zeolite, Tricalcium phosphate, activated bone char, magnesite, magnesite etc

 Precipitation method:-
In a high PH condition, co-precipitation of several elements in water
with fluoride ions forms fluoride salts- flocculation (Aluminum ions)
Alum
Alum and lime
Lime softening
Calcium chloride

Membrane separation
 Reverse osmosis process
 Expensive developing countries
 30% of raw water is lost in the process

Indian technology for
defluoridation
 Nalgonda Technique:
India in 1975
most simple
least expensive
Easiest to operate

Fluoride water
Supply Disinfection Filtration
settling
Flocculation
Alum
NALGONDA TECHNIQUE

Advantages:
 domestic and community levels
 manually possible
 cost effective
 flexible design to use in different location

Prashanthi technology
 Activated Alumina- most popular
cost effective
Bio-Science, Department of Sathya Sai University of Higher Learning in Prasant
Nilayam

Other methods tried in India.
 Fish bone charcoal- University of Roorkee
 Drumstick Moringa cleifera- Reduce water turbidity
-calcium and magnesium levels in plants
 Askali- extract mycetial biomass-Osmania university
Aspergillus riger
 Clay materials-Montmosllonite KSF, Kaolin and a Silty
Clay Sediment series
 Tricalcium phosphate(TSP)

CONCLUSION
⦁ Fluoride in recommended concentrations is definitely beneficial to health.
⦁ In excess amount it is harmful to the body.
⦁ Appropriate fluoride intake in different population groups in different areas has to be
ascertained on the basis of fluoride concentration in food and water resources taken by
the local population.

THANK
YOU