In t roduct ion• In the fields of dentistry the discovery of fluorides

probably represents such an epoch making event, the impact of which has changed altogether the concepts of preventive dentistry.

• Fluoride element is the most electro negative ,which never exists in free state in native but mostly combined chemically with other elements as fluoride compounds, it has not only notable chemical qualities but also physiological properties of great importance for human health and well being. Its selective effects on the hard tissue of the body attribute significantly to prevent and control dental caries.

SOURCES OF FLUORIDES

• Fluorine is one of the physiologically essential elements for normal growth and development. It is the 13th most frequently occurring elements which represents 0.06%to 0.09% of the earth crust.• Fluorine is a yellowish green diatomaceous gas.

The highest fluoride value has been recorded in the rift valley of Kenya.{2800mg per kg -5600mg per kg in soil} fluoride in atmosphere is highest in the vicinity of fertilizers factories and industry involved in production of plants uranium and aluminum. Plants like tea also contain fluoride.• Fish have a high content of fluoride because

oceans contain about 1 ppm of fluoride.

ENVIRONMENTAL LEVELS AND HUMAN EXPOSURE

AIRAirborne fluoride exists in gaseous and particulate

forms, which are emitted from both natural and anthropogenic sources. Fluoride released as gaseous and particulate matter is deposited in the general vicinity of an emission source, although some particulates may react with other atmospheric constituents.

• Fluoride levels in surface waters vary according to location and proximity to emission sources. Surface water concentrations generally range from 0.01 to 0.3 mg/litre. Seawater contains more fluoride than fresh water, with concentrations ranging from 1.2 to 1.5 mg/litre.

WATER

SOILFluoride is a component of most types of soil, with

total fluoride concentrations ranging from 20 to 1000 µg/g in areas without natural phosphate or fluoride deposits and up to several thousand micrograms per gram in mineral soils with deposits of fluoride.

TERRESTIAL BIOTA• Fluorides can be taken up by aquatic organisms

directly from the water or to a lesser extent via food. Fluorides tend to accumulate in the exoskeleton or bone tissue of aquatic animals

• Mean fluoride concentrations of 150–250 mg/kg were measured in lichens growing within 2–3 km of fluoride emission sources, compared with a background level of <1 mg fluoride/kg.

FOOD STUFF

• Virtually all foodstuffs contain at least trace amounts of fluoride. Elevated levels are present in fish. Tea leaves are particularly rich in fluoride

• The concentration of fluoride in food products is not significantly increased by the addition of superphosphate fertilizers, which contain significant concentrations of fluoride (1–3%) as impurities, to agricultural soil, due to the generally low transfer coefficient from soil to plant material

• 1901: Doctor Frederick McKay of USA discovered permanent stain on teeth and referred them as ‘colorado brown stains’ later named as mottled enamel.• 1916:McKay and Brown examined 6873

individual in USA and reported that unknown causative of mottled enamel was possibly present in domestic water during the period of tooth calcification.• 1931: identification of chloride in drinking

water,a discovery made independently in three different places at about the same time.

HISTORY OF FLOURIDES

• 1941:”21 city” study carried out by Dean et al.

The part consisted of clinical data from children 12 to 14 year’s old living in area with stable mean fluoride levels. The project later added 13 additional communities. This was the landmark epidemiologic survey which leads to adoption of 0.7-1 mg fl/lt of water as optimum amount of fluoride and drinking water.• 1945:World’s first artificial fluoridation was

started at Grand Rapid,USA.• 1969:Fluoridation was endorsed by WHO

PHYSIOLOGY OF FLUORIDES• METABOLISM Source of fluoride The principle source of human fluoride ingestion is

water. It is present in nearly all ground water, though

concentration in water supply is very small. It is also derived from plants, marine animals and

even dust particles. Fluoride content varies in different types of food

like Certain types of fishes, dried mackerel and dried

salmon contain a large amount of fluoride i.e. 84.5ppm.Potatoes give 6.4 ppm

Tea contains an average of 97ppm.

• CHEMISTRY OF FLUORIDE Chemically fluoride is so violently reactive

that it rarely or never occurs in nature as elemental fluorine. Its atomic weight is 19.0 and exits chemically in form of fluorides, chiefly as:

Fluorspar(CaF2) Fluor apatite(Ca10(PO4)6F2) Cryolite(Na3AIF6)

• ABSORPTION AND DISTRIBUTION The major route of fluoride absorption is

through GIT. They may also be inhaled from air borne fluorides. Fluoride which is ingested is absorbed mainly from stomach and intestine mucosa. It has been shown that absorption is inversely proportional to pH of the stomach content. From there it is carried by blood and distributed to various tissues like

Mineralizing tissues, teeth and bone Salivary gland, Soft tissues

• FLUORIDE AND BLOOD PLASMA Blood plasma has been considered as

central component in the transportation of fluorides in body. Fluoride levels peaks in 30 minutes and after 24 hrs it declines. There is no homeostatic regulation of these levels.Thus,there is no psychological plasma fluoride concentration. In plasma fluorides exists in two forms;1)ionic 2) Non ionic

A wide range of normal plasma fluoride concentration

[0.7-2.4microns/ml] has been coined by various scientific literatures.

• FLUORIDE IN SOFT TISSUES Fluoride from the plasma is distributed to

all the tissues and organ of the body. The rate of delivery is dependent on the blood flow in the tissues. Fluoride is concentrated at high level in kidney tubules. The blood brain barrier prevents passage of fluoride in to CNS , where the fluoride concentration as about 20% of that of plasma, is seen in adipose tissue. The fluoride concentration of plasma and extra cellular fluid are higher than that of intracellular fluid.

• FLUORIDE IN HARD TISSUES About 99% of all fluorides in the human

body are found in calcified tissues such as bone and teeth

BONE Fluoride is present to a great extent during

active bone formation and it eventually reaches a constant level. It is present to a greater extent in cancellous bone. Bone fluoride content increases rapidly in young people but as fluoride balance is achieved the uptake becomes slower and eventually reaches a steady state when fluoride intake is constant.

TEETH Fluoride in teeth is present in the highest

concentration in cementum.Also,developing enamel tends to absorb fluoride actively due to its porous nature. The fluoride content of tooth tissues reflects the biologically available fluoride at the time of tooth formation, in the bulk of enamel.

• FLUORIDE IN PLACENTA AND FOETUS

Earlier it had been thought that the placenta act as the barrier between the maternal blood and the foetus.This is not so ,fetal blood infact;contain 75% of maternal blood fluoride concentration.

• FLUORIDE IN PLAQUE Dental plaque is the main storage source in

oral activity .Its concentration in plaque is many times higher than in saliva, especially gingival crevicular fluid where it is 10% to 20% more than plasma concentration of fluoride.

• FLUORIDE EXCRETION 10%-25% of daily intake of fluoride is not

absorbed and is excreted in faeces.The elimination of absorbed fluoride occurs almost exclusively via the kidneys.Fluroide is also present in sweat, feaces, tears, breast milk etc.

BIOMARKERS OF FLUORIDE EXPOSURE

• Urine ,• plasma,• saliva,• Teeth,Hair • Nails

Total Body Fluoride Is Reflected By -

• Bones• teeth

MECHANISM OF ACTION

Fluoride role in decreasing the prevalence of caries has been

well accepted for many years

It is now determined that presence of fluoride in and on

enamel surfaces is the key to effectiveness of fluorides.

It is incorporated throughout the tooth crown formation

during development

ROLE OF LOW FLUORIDE IN ORAL ENVIRONMENT

• Brown co workers (1996) predicted that low concentration of fluoride could enhance remineralusation.Since fluoride ion is most effective at enamel saliva interfere, it is believed that it is beneficial to provide fluoride ions at that interfere. It provides and maintains caries at inactive state.

GOALS OF FLUORIDE (F) ADMINISTRATION

Do no harm

Prevent decay on in tact dental surfaces

F

F

Arrest active decay

Remineralize decalcified teeth

1.

2.

3.

4.

F

Fluorosis or toxicity

FLUORIDE ADMINISTRATION• SYSTEMATIC FLUORIDE Fluoride after ingestion can get absorbed and

incorporated into developing enamel and can benefit teeth before eruption .It also benefits the teeth eruption, when it returns to mouth in saliva and gingival exudates.

• COMMUNITY WATER FLUROIDATION Community water fluoridation in the process adjusting

the amount of fluoride in a community water supply to an optimum level for the preventation of dental caries.

Studies have shown that adjustment of fluoride concentration in drinking water to the optimum level of 1 ppm is associated with marked decrease in dental caries.

• FLUORIDE COMPOUNDS USED IN WATER FLUORIDATION

Fluorspar Sodium fluoride Silicofluoride Sodium silicofluoride Hydrofluosilicic Ammonium silicofluoridr

• EQUIPMENTS USED IN WATER FLUORIDATION

There are three systems of water fluoridation

Saturated system Dry feeder system Solution feeder systemBENEFITSThis method is preferred since some tooth

surfaces receive greater protection against caries than other.

Water fluoridation has both pre-eruptive and post-eruptive effects.

SCHOOL WATER FLUORIDATION• School water fluoridation is the adjustment

of the fluoride concentration of a schools water supply for caries prevention• School water was fluoridated to provide

maximum cariostatic effect in developing teeth. since children spend only 6 to 8 hours in school, concentration of fluoride should be 4 to 6 times more than that designated for community water

DIETARY FLUORIDE SUPPLEMENTS• Dietary fluorides supplements are administered in

the following form:Fluoridated milk: milk fluoridation is suggested as

an alternative to water fluoridation for caries prevention

Fluoridated salt: the addition of fluoride to table salt is a feasible way to deliver systemic fluride,particularly in countries that lack a widespread municipal water system

Fluoride in sugar: several studies have shown that adding fluoride to sugar and sugar products has potentially reduced the cariogenic effects of the sugar or fermentable carbohydrates among population groups

Fluoride in citrus beverages:Citrus beverages may also be considered as a potential vehicle for the administration of fluoride as dietary supplements

Fluoride drops: was prescribed in prenatal supplements for potential caries prevention in teeth where development begins in intrauterine life and at birth

Fluoride drops with vitamins

Fluoride tablets/lozenges Fluoride tablets with vitamins

Fluoride oral rinse supplements. they provide both a systemic and a topical effect. The patient swishes the solution producing a topical effect ,and then swallows the solution,providing alters systemic effect

TOPICAL FLUORIDEThese act by inhibiting demineralization and promoting

remineralization at the tooth to oral fluids interface They can be

USED AT HOMEFluoride dentifricesFluoride mouth rinsesFluoride floss

PROFFESIONALLY APPLIEDFluoride solutionFluoride gelsFluoride varnishes

OTHER FORMS

• Fluoridated tooth picks• Fluoridated chewing gums• Saliva substitute containing fluoride

USED AT HOMEFLUORIDE DENTIFRICESFluoride containing tooth paste now accounts 85%

dentifrices market in the worldThe council of dental therapeutics of the ADA

CURRENTLYRecognizes few caries preventive dentifrices with

ADA seal. they all contain between 1,000 and 15,00ppm fluoride formulated from both sodium mono-fluorophosphate and none contains stannous fluoride

ADVANTAGESThey provide a frequent source of fluoride in low

concentration that can inhibit demineralization and enhance remineralization

DENTIFRICE (TOOTHPASTE,TP)

Gels:

1. Better interdental penetration

2. More acceptable to children

PastesKey ingredients in TP:

1. F salt

2. Abrasive

DENTIFRICE

1. 0.2% NaF

2. 0.76% sodium monofluorophosphate (MFP)

3. 0.4% stannous F

4. Amine F

1 gram of TP = 1 mg F

Na

FPO4

MFP does not react with calcium abrasives (F is covalently bound) and has better uptake by enamel crystals.

Na

F

The ADA requires that 60% of free F ion be

available over the shelf life of the TP. NaF and MFP lose about 20% free F in 2 years.

F salt (all reach 1000-1500 ppm F)

F salt in TP:

FSn

F

SnF2 exhibits less shelf life and may cause dental staining

F

Amine F is not sold in the US. It adsorbs to enamel and has anti-bacterial properties

F USE CONSIDERATIONS

F

FF

F

F

F

Evidence shows that increased F use and F concentration increases bioavailability in stagnation sites.

(Note: be aware of fluorosis susceptible patients.)

FS

P

T

FS

P

T

F F

F

F

awake

asleep

High salivary flow

Low salivary flow

Brush before bedtime

Rinsing after brushing

reduces F effectiveness by 50%.

Recommendations: Do not rinse after brushing or rinse with a F rinse.

HOME F RINSES

ACT

0.05% NaF, 0.023% free F, 230 ppm F, 2.3 mg F / dose

Daily Rinse:

PHOS-FLOR

0.02% APF, 0.02% free F, 200 ppm F, 2 mg F / dose.

Weekly Rinse

PREVI-DENT

0.2% NaF, 0.091% free F, 910 ppm F, 9.1 mg F / dose.

Indications:

1. High caries risk

2. Exposed roots

3. Prevention programs

FLUORIDE TOXICITYIt is said that "GOOD THINGS SHOULD BE

TAKEN….IN PROPER DOSES". This applies to wonder element of dentistry i.e. fluorides. If taken in a quantity that exceeds the normal doses,fluoride can prove to be dangerous.Hence it is called “A DOUBLE EDGE SWORD”,and it should be recommended that a large can kill within minutes.

Fluoride toxicity can beACUTE TOXICITYCHRONIC TOXICITY

• ACUTE FLUORIDE TOXICITY

Fluoride toxicity occurs from ingestion of a large amount of fluoride.This could happen because of ingestion of fluoride containing products such as pesticides or dental care products like mouth rinses or tablets,drops,etc.Ofthe reported cases,90% cases occurred in children.

Over fluoridation of communal water supplies has led to cases of fluoride poisoning and fatalities have been reported.

• PROBABLY TOXIC DOSE(PTD)

The probably toxic dose of fluoride is the minimum dose that could cause serious or life threatening systemic signs and symptoms and that should trigger immediate therapeutic intervention and hospitalization. The exact dose cannot be accurately stated but taking into account all the reported doses which have caused complications,we can say that an oral fluoride dose of 5.0mg/kg body weight should be considered as PTD.This does not mean that doses below 5mg/kg weight are harmless.

The PTD is 5 mg F/kg body weight. For a 20 kg 5 to 6 year old this would be 100 mg and for a 10 kg 2 year old, 50 mg. F content of dental products or treatments may exceed these values for young children. For example, a gel tray containing 5 ml of APF contains 61.5mg F (F is absorbed more quickly when in acidic form.), 100ml of 0.2 or 0.4% F mouth rinse contains 91 or 97mg F and a tube of fluoridated toothpaste contains as much as 230mg F. Sub-lethal toxic symptoms are manifested quickly after the dose and consists of vomiting, excessive salivation, tearing and mucous discharge, cold wet skin and convulsions with higher doses.

TOXICITY OF FLUORIDE COMPOUND

Sodium fluoride and stannous fluoride are generally supposed to have more potential of causing acute toxicity than monofluorophosphate,calcium fluoride or cryolite.

SIGN AND SYMPTOMSNauseaVomitingEpigastric distressExcess salivationDiarrhoeaMucus discharges from the nose and mouth

• Counter measures which should be administered immediately are emetics, 1% calcium chloride, calcium gluconate or milk. (Calcium reacts with F in the GI tract and prevents its absorption. The most serious consequences of F toxicity stem from reactions of cationic electrolytes with systemic F.)

HeadacheSweatingHypotensionCardiac arrhythmias Disturbances in electrolyte balance i.e.

hypocalcemia Hyperkalemia.Barely detectable pulseRespiratory and metabolic acidosisComa

POTENTIAL HARM

5 mg F / kg body weight

20 kg 6 year old, PTD= 100 mg F

10 kg 2 year old PTD = 50 mg F

230 mg F/ tube toothpaste

ACT91-97 mg F/ container of F mouthrinse

Symptoms:

1. Vomiting

2. Excess salivary and mucous discharge

3. Cold wet skin

4. Convulsion at higher dose

Probable toxic dose:

Topical F, 12,300 ppm F pH= 3.5

61.5 mg F/ 5 ml

F

Ca

F

Ca

Counter Measures:

1. Emetics

2. 1% calcium chloride

3. Calcium gluconate

4. milk

Divalent cations like Ca cause precipitation, of F and prevent absorbtion in the intestine.

F Ca

F

Ca

F Ca

FCa

FCa

FCa

A serious systemic consequence is binding of F to Ca which needed for heart function.

POTENTIAL HARM

F Ca

FCa

FCa

FCa

TREATMENT

• All attempts must be made to eliminate the toxic dose of fluoride from the body and

Minimize the further absorptionSupport vital signsAdministration of an emetic if patient possesses a

gag reflex i.e. if he is not vomiting he is not unconscious and not having convulsions.

Investigations of blood should be done for pH,palsma fluoride concentration and serum chemistry profiles.

An intravenous line should be secured and glucose to be reversed hyperkalemia and calcium gluconate to maintain sodium and calcium levels must be given.

Sodium bicarbonate or ringer’s lactate must also be given to:

Increase urinary flowDecrease acidosisIncreases Ph and thusIncreases excretion of fluoride Continuously monitoring of the patient till the

normalcy is attained, is must.

CHRONIC FLUORIDE TOXICITY

Fluoride has been made the scapegoat for many accusations. It has been reported to cause

Allergy Carcinoma Birth abnormalities Mutation and other genetic disorders.After an extensive research it is now thought there

is no detectable risk of cancer in humans associated with consumption of optimally fluoridated water. Fluoride is not associated with Down’s syndrome or any birth abnormality. At present, there is no indication ,which suggest that organ system are affected by fluoride.

SKELETAL FLUOROSIS

This is also called osteofluorosis.A water fluoride level over 4ppm cause a mild variant but levels over 8ppm cause severe skeletal fluorosis.

FEATURESIncrease bone densityChange in bone contoursIrregular periosteal growthSpinal column and pelvis show roughening and

blurring of trabeculae.Bone appears as marble white shadow and the

configuration is woolly.The cortex of long bone is thick and dense and the medullary cavity is diminished.

Ligamental and tendon calcification with vague pain in joints.

Stiffness and limitation of joint movements, immobilizing the patient-crippling fluorisis.

Arthritic changes ,cataract,thyroid problems,tumors and cysts,fractures,urinary and gallstones may be seen.

DENTAL FLUOROSIS

Chronic consumption of high levels of fluoride from drinking water results in dental fluorosis.

McKay described the condition as “mottled enamel” characterized by' minute white flecks, yellow or brown area scattered irregularly or streaked over the surface of a tooth ,or it maybe a condition where the entire tooth surface is of dead paper white color’

In 1931,the US public health services appointed Trendely H.Dean to pursue full time research on mottled enamel.

He formulated an index ,know as Dean’s fluorosis index, to calibrate his findings.

Dean’s fluorosis IndexScore Criteria

0 NORMAL-enamel appears translucent ,smooth and glossy

1 QUESTIONABLE-enamel shows white flecks to an occasional white spot.

2 VERY MILD-small opaque paper white areas scattered irregularly over the tooth surface.

3 MILD-the white opaque areas are more extensive but not involving greater than 50% of enamel

4 MODERATE- all enamel surfaces affected brown stain is distinguishing marked attrition.

5 SEVERE-hypoplasia is marked. General shape of the tooth is affected

moderate

severe

mild

pitting

• Fluorosis occurs when teeth are developing. The most critical ages are from 0 to 6 years. After 8 years, risk of fluorosis is essentially past. During the critical ages F intake in excess of 0.1mg/kg body weight/day can lead to fluorosis. This is roughly 1mg/day for a 1 to 2 year old or 1.5 to 2 mg for a 5 year old. Remember that all forms of F intake comprise the daily consumption. This includes water intake (up to 1.5mg/day), foods (0.3 to 1.0mg) and especially significant in young children, swallowed toothpaste. Children under 2 years swallow 50% of toothpaste during tooth brushing and at 5years, 25%, both of which may amount to 1mg F/day.

10

9

8

7

6

5

4

3

2

FLUOROSIS

0.0 0.5 1.0 2.0 3.0 4.0

DMFT

PPM F IN DRINKING WATER

slight

severe

moderate

mild

F in excess of 0.1mg/ kg body weight = fluorosis

POTENTIAL HARM

FLUOROSIS

F

F

Excess F affects mineralization of developing teeth

Up to age 6 is the critical age for fluorosis. After age 8, risk is past.

Enamel prism

FLUOROSIS

F in excess of 0.1mg/ kg body weight = fluorosis

Maxium safe dose for a 5 year old = 2 mg F / day

Maxium safe dose for a 2 year old = 1 mg F / day 1 2 3 4

mg F

supplements toothpaste

fluids food

DW Banting JADA 123:86,1991

Daily F intake of a 20 kg 4 year olds with different water F

0.5 ppm water F1.2 ppm water F

FLUOROSIS

Children under 2 years swallow 50% of toothpaste

5 year olds swallow 25% of toothpaste

Toothpaste = 1 mg F / gram (1000 ppmF)

1 to 3 grams

“pea” size amount (0.5g) is recommenred for fluorosis susceptible children.

• TREATMENT

Dental fluorosis presents an aesthetic concerns for the patient and hence aesthetic restorative techniques have been advocated.

For milder forms of fluorosis,rubbing the teeth with 18% hydrocholoric acid(with or without heat)and treatment with 30%hydrogen peroxide is used

Croll(1989)suggested that these techniques can be enhanced by microabrasion or grinding of the surface layer.

Severe forms require composite restoration of full ceramic crowns

METHODS OF MINIMIZING TOXICITY

• The danger of acute toxicity is high in cases of tropical fluoride treatment where the teeth are treated with the high F containing solution or gel at one time. Hence,

Upright position of patient, head incline forward

Use of custom made trays.Use of saliva ejectorUse of minimum amount of gel required is

recommended.

DEFLUORIDATION

Defluoridation is a scientific means to improve the quality of water with high fluoride concentration by adjusting the optimum level in drinking water

METHODSADSORPTION AND ION EXCHANGE METHODSome substances adsorb fluoride ion by the surface

and it can exchange its negative ion such as OH group for fluoride ion. Thus the concentration of fluoride in water decreases for eg.activated alumina, fluidized activated alumina.

PRECIPITATION METHODIn high pH condition,co-precipitation of several

elements in with fluoride ions forms fluoride salts.for eg.alum,alum and lime

METHODS BASED ON MEMBRAME SEPERATION

In the industrialized world’reverse osmosis’process is well know.

All elements in water get diminished after filtration.

INDIAN TECHNOLOGY FOR DEFLUORIDATION

• NALGONDA TECHNIQUE

This technique first developed in India in 1975,is the simplest, the least expensive and the easiest to operate of all the other method of Defluoridation.

USING LIME AND ALUMThe first community plant for removal of fluoride

from drinking water was constructed in the district of nalgonda in Andhra Pradesh, in the town of kathri,thus the name of technology.

• PROCEDURE

RAPID MIX: rapid mix is an operation by which the coagulant is rapidly and uniformly dispersed though the single or multiple phase system.This helps in the formation of microflocs and results in proper utlization of chemical coagulant,preventing localization of concentration and premature formation of hydroxides which lead to less utilization of coagulants.

FLOCCULATION: flocculation is the second stage in the formation

of settable particles(FLOCS)from destabilized colloidal sized particles and is achieved by gentle and prolonged mixing.

SEDIMENTATION: it is the seperation from the water by gravitational setting of suspended particles that are heavier than water.

FILTERATION: this is the final step. The water is allowed to stand for about an half an hour and the water collected is utilized for drinking.

DOMESTIC USEIn rural areas this method is advised for domestic

use of defluroidation of drinking water as required. This advise is given to mix water,lime and alum in a close big vessel and leave it overnight,so that next morning the clean supernatent is decantedfor use and is safe for consumption

ADVANTAGES OF NALGONDA TECHNIQUE

This method can be used both at domestic and community levels.

Operation are possible manually.The chemical are same as those used in municipal

urban water supply.It is cost effective.Designs are flexible to use at different locations.Defluoridation meets with standard laid down by

the Bureau of Indian Standard(fluoride content less than 1mg/l).

Other techniques used areCombined Nalgonda and calcined Magnesite

techniquePrasanti technologyOther materials tried in IndiaFish bone charcoalDrumstick plantAskali-extract mycetial biomassClay mineralsTricalcium phosphate

COMBINED NALGONDA AND CALCINED MAGNESITE TECHNIQE

In this plant the Nalgonda tech nique was passed through a filter bed of calcined magnesite granules. Fluoride was absorbed by the calcined magnesite granules, there was a rise in pH over 10.0 method is found impractical for rural regions .

PARASANTI TECHNOLOGY: In Indian villages this method of utilizing

Activated Alumina is found to be most popularand cost effec tive material for defluoridation.

Drumstick plant (Moringa Cleifera) Was also used as an alternative to defluoridate drinking water as it is easily accessible and it has been widely used to reduce water turbiditY because of its excellent coagulating and clarify ing properties. ALkali - extract mycetial biomass ability of this material from Aspergillus riger to bind fluoride from fluoride containing water but the mechanism is still not clear.

There is general agreement that when applied with the correct technique they affect an overall reduction in caries attack rate approximately that of water fluoridation. More recently fluoride tablets, mouth washes, and dentifrices have been reported to limit dental caries.

S.NO

NAME OF BOOK AUTHOR EDITION

1. Textbook of pedodontics

Shobha Tandon

2nd edition

2 Textbook of pediatric dentistry

S.G.Damle 2nd edition

3 Principles and practice of pedodontics

Arathi Rao 1st edition

4 Pediatric dentistry Jimmy R.Pinkham

4th edition

5 Clinical pedodontics Finn 4th edition

6 Textbook on fluorides

Amrit Tiwari

-

7 Comprehensive pediatric dentistry

Nikhil Marwah

1st edition

8 Fluorides in caries prevention

J J Murray 3rd edition

9 Preventive and community dentistry

Soben Peter

3rd edition

BIBLIOGRAPGHY