Systemic Flourides

7/28/2019 Systemic Flourides

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Systemic fluorides

Dr G. kayalvizhi


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Contents

Introductionwater fluoridation

School water fluoridation

Salt fluoridation

Milk fluoridationFluoride tablets and drops

Prenatal supplementation

Defluoridation

Conclusion

references


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Water fluoridation

Definition upward adjustment of the concentration

of fluoride ion in public water supply in such a waythat the concentration of f ion in the water may be

consistently maintained at 1 ppm.


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Optimal level of fluoride

Optimum fluoride concentrationWHO 1971 0.7-1.2ppm

Cold climate -1.2 ppm

Hot climate 0.7 ppm

Moderate climate 1ppm

WHO 1994- 0.5-1ppm

Galagon and vermillion 1957 based on body wt & climaticconditions = ppm F (conc.) = 0.34/E

Where E = -0.038+0.0062 x temperature of the area in 0F


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Choice of equipment and chemicals used

Fluoride compounds

Fluorspar- caf

hydrofluosilicic acid

Sodium fluoride

from hydrofluosilicic acid(expensive)

Silicofluorides purification of phosphate rocks

Sodium silicofluoride (low cost but corrosive)

ammonium silicofluoride


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Equipment

Characteristics of systemEquipment should be adapted to local conditions

Safe and efficacious, precise

Standard type

Well defined precision limits

Antisiphon mechanism

Types of equipment for water F

Saturator granular Na F

Dry Distributor silicofluoride or Na F

Liquid distributor hydrofluosilicic acid


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equipment principle Factors

limitingutilisation

recommenda

tion

Saturator

system

4% saturated

solution of NaF

(pump)

High hard

water level

Small towns


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Volumetric feeder

Saturator system

Solution feeder


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Two other systems

Venturi fluoridator system J.N.Leo

Non-electrical system

Activated by the flow of water in the main water

lineAdv- Simple to install, low cost

Saturation suspension cone- brazil

Upside down cone charged with a bag ofsilicofluoride- collected at the top


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Venturi fluoridator

Saturated- suspension cone


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Method of estimation of fluoride concentration in

drinking water

fluoride electrode coupled with ph meter

(orion, radiometer)

Scot- sanchis methodZirconium alizarin reagent


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Study year place Ppm

F

result

Dean et al 1939 Galesburg,monmouth 1.7 dmft

weaver 1944 South& north

shields

1.4

0.4

41% dmft

Tan&

storvick

1964 Corvalis albarny 1 56% dmft

Murray 1969 Hartepool,york 1.5-2 64% dmft

Murray &

Atkinson

Backerdirkis

1971

1974

London

Holland & new

zealand

0.2 93% dmft

Prox& gingival

caries

Whittle &

downer

1979 Birmingham

salford

F/NO

N-f

54% dmft

Water fluoridation studies


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Benefits of water fluoridation

Smooth surfaces receive maximal protection

Has both pre and post eruptive effects

Systemic and topical effect

Fluoride in saliva

remineralisationChanges morphology of Occusal surfaces

Least expensive large group

Bottled beverages- diffusion/ halo effect


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Safety of water fluoridation (1940-1978)

Leone et al 1959-

Bart let Texas- 8ppm F (15yr) mottled enamel

` Cameron- 0.4ppm

Weidman 1963up to 4ppm- no radiographic evidence

Hodge 1963 11ppm- no kidney/ thyroid damage

Ericson 1978 no evidence of cancer

WHO 1978 no harmful effect, less dental decay


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Limitations of water fluoridation

Financial and technical resources

Fear of adverse effects

Implementation of fluoride schemes

Feasibility in India

Most effective, practical and economical public health

measure

Shortcoming central pipe water supply system (30%)


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India does not need water fluoridation an

illusion

Rama Subramanian et al 1979

7 states A.P, tamilnadu, gujarat, maharashtra, U.P, himachal

pradesh & punjab

A.P & gujarat -6-16PPM

only 5% - high F area

3% - optimal F area

90% - water deficient F

66% -


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Alternatives to water fluoridation


Fluoridated salt

Milk

Fluoride tabletsFluoride drops

Fluoride oral rinses


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1954 Virginia island, 2.3ppm,

1962 - 21.9% caries reduction

Pennsylvania 5ppm

5yrs

28.6%, 10yrs

39% less dmft

USA - North Carolina- Vermont, Kentucky, Nebraska,Florida, Montana

Heifetz et al 1983

12yr study (6.3ppm)

47% reduction

Results of these several studies - Effective publichealth measure


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Venturi fluoridator system

Advantages

Effective public health measure

Disadvantages

Limited pre eruptive contact (5-6yr)

Intermittent exposure of F to children (5-6hrs 4.5ppm

over dosage


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Salt fluoridation

Introduced in Switzerland 1955

Salt fluoridated 90 mgF/kg (canton of Zurich)

250mgF/kg (canton of vaud 1970)

Belgium, France, Germany, Spain, Hungary

Clinical trials

Wespi et al 1955 20-25%

Muhlemann 1967- 300mgF/kg - 1.5mgF/5gm of salt

Toth 1976 250mgF/kg salt - 41% (2-6yr) - 8yr

- 58%(7-11yr)- 36% (12-14yr)


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Production of fluoride containing salt

Spraying conc. solutions of NaF on salt on a conveyer belt(Switzerland and Hungary)

NaF & CaF mixed Po4 - salt (U.S.A)

Requirements for application of fluoridated salt

Low fluoride drinking water

Lack of political will and resources to fluoridate water


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Factors favoring the implementation of saltfluoridation in Switzerland

Decentralized water supply

Uniform low water FCentralized salt production

Public ownership

Low cost


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Advantages of salt fluoridation

SafeSupplement

Consumer free choice

No supervised water distribution systems

Lifelong daily compliance

Small amounts

Low cost

Disadvantages

Low consumptionSafety - Hypertension ?

No problem of acute toxicity


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Limitations

Limited to domestic salt

Variation in salt intake

Difficulty in controlling the distribution of various conc

Requires refined salt produced with modern technology

Technical expertiseMultiple sources of water


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Feasibility in India

Effectively controlled supply

Individual monitoring not required (5-8gms of salt/day)

Freely availableCariostatic effectiveness and excretion

Does not alter its color


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Milk fluoridation

Ziegler 1955 (Swiss city of winterthur)

0.03 ppm F (Erickson 1971)

Compounds

NaF- conc. aqueous solution

disodiummonofluorophosphate

reacts cadisodiumsilicofluoride pasteurized milk

Manufacture

fl added to milk in appropriate quantity

Fluoridated milk- pasteurized / sterilised (liquid)- powder

WHO 1994 - 0-1mgF/day (age+water F)


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Studies

Inamura 1956 (Japan) 36.3% - (2.5mg NaF )

Rusoff et al 1962 (U.S.A)

35% (3.5ppm F)Benoczy 1984 longitudinal study (3-9yr old) 3yr

200ml milk +0.4mg F (3-5yyr old)

0.75mgF (6-9yr old)

Primary teeth

Ziegler 1964 14 31% (1ppm)

Benoczy 1983 74%

Effectiveness of milk F

bioavailability is not reduced

promotes remineralisation (low level of ionised F)


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Rationale

Target children directly

Less expensiveConsumers choice

Advantages

Staple food

Consumption confined to groups who need it most

Concerns

Absorption long

Children who do not drink milk / consumption declines withage


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Stamm 1972 4 criticisms of milk fluoridation as public

health measure1) low socioeconomic

2) less benefit

3) cost

4) slow absorption

Feasibility of milk fluoridation in India

Controversy binding and complexing of F + ca, p

Ericson1958

4hrCannot afford milk

No centralised milk supply system

Variation of intake and quantity


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fluoride supplements

1940 , pre eruptive effect

Common dietary supplements-

Fluoride drops

vitaminsFluoride tablets - vitamins

Lozenges

Oral rinse supplements


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Commercially available

NaF tablets

fluoroday

tymafluor,

luride (U.K)

Vitamins

dosage

2.2mg (1mgF)

1.1mg (0.5mgF)

0.55mg (0.25mgF)

APF tablets/ KF/CaF

Drops

0.125,0.25,0.50mg

Oral rinse

1mg/5ml


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Luride Chewable Tablets Luride drops

Fluor-A-Day Chewable Tablets


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Lozenges oral rinse

Sodium fluoride tablets and drops


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Factors to be considered before

determining proper F dosage

Concentration of fluoride in drinking water

Total amount of bioavailable fluoride

Age of the child

Dosage forms commercially availablemilk & milk products


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Fluoride dosage based on F content of drinking

water (ADA)

F content of

drinking water

2wks-2yr 2-3yr 3-14yr

0.7ppm - - -


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Recommendations to fluoride supplements(British society of pediatric dentistry)

1) Not a public health measure- recommended for individual

children

2) 6yrs 1mgF/day


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Indications for use

No central water supply

low F conc

parental motivation high

Interim measure

Water/ salt F cannot be implemented

Frequent changes in work

Precautions

Stomach upset

Risk of mild fluorosis


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Effect of fluoride tablets on deciduous teeth

Hoskova 1968 93% (prenatally) 82%

- 54% (birth) 56% (kailis et al)

Since birth 6-8yr -40% (Prichard 1969)

- 3 yr 78% (hennon 1971)

After 3yr 0-38%

Caries reduction 50-80% (bef 2yr 3-4yr)


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Effect of fluoride tablets on permanent teeth

Sodium fluoride tablets

0% caries reduction Bibby 1955

33-38% (Berner 1967, Pollack 1960)

APF tablets

23- 30% (depaola 1968,aasenden 1972)

Aasenden& peebles 1974 -0.5mgF daily (


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Prenatal fluoride supplements

1966 FDAbanned marketing of products bearing claim thatcaries would be prevented in their offspring of women who

used the products in their pregnancy

Rationale for the use of prenatal fluorides in cariesprevention

Transfer of F from maternal circulation to fetal circulation

Clinical trials with prenatal fluorides

Pl t l t f f F ?


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Placental transfer of F ?

1) Fluorosis in primary teeth - thylstrup (3-21ppm)

2) Prenatal fluoride metabolism


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3) Elevated maternal blood conc. ?

4) Prenatal exposure to fluoridated water

- blayney & hill, tank & storvick 1964- benefit primary teeth- Horowitz & heifitz 1967, Katz & muhler- minor

- Carlos 1962 - prevalence differed

- Arnold- greater reduction- pre/post

5) fluoride supplements- felt man & kozell 1961- pre+postnatal

- Pritchard

-Glenn study 1977-79- prenatal

Legros et al 1983 protect teethChanging the morphology of teeth

Densely placed enamel rods

No evidence


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Defluoridation

Deflouridation - scientific means to improve the

quality of water with high fluoride conc by

adjusting the optimum level in drinking water

Methods

Adsorption and ion exchange methods

Adsorb F + exchange negative ions

activated alumina, fluidized activated alumina, activated

bauxite, zeolite, tricalcium phosphate,super phosphate,

activated bone char, magnesite


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Precipitation method- High ph co-precipitation of several elements +

fl ions

- Alum, alum + lime, lime softening, CaCl

Methods based on membrane separation

Reverse osmosis expensive

30% of raw water is lost


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Reverse osmosis unit


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Ion exchange resins

Anion exchange resins

- polystyrene, quaternary ammonium

- 10-15 cycles replacement - High cost, unacceptable taste.

Cation exchange resins

- saw dust carbon, defluoron 1, carbion


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Defluoron 1

Sulphonated saw dust impregnated with 2% alum.

High attritional losses (bhakuni 1964, 1970)

Carbion

Good durability , bulk density 680g/lt

Pilot plant gangapur - Rajasthan (4.8ppm)

8:1 Carbion & defluoron 1, alum


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Magnesia (Thergaonkar 1971-73)

removed excess fluoride- ph>10High cost, large conc., complexity of preparation

Defluoron 2 (1968)

Sulphonated coal +alum cycles, 2-4yrs life

regeneration and maintenance of plant skilled operation


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I di t h l f d fl id ti


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Indian technology for deflouridation

NEERI ,Nagpur - 1960

Nawlakhe 1974

Nalgonda technique 1975 (Andhra Pradesh)


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Nalgonda technique (Nawlakhe 1974)

Addition of 2 readily available chemicals

Sodium aluminate /lime- hastens settlement of ppt

bleaching powder disinfection

filter alum added to F water

Domestic / community water supplies


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Domestic treatment

container 20- 50lt

Lime water + bleaching

powder

Alum solution (10min)

Clear water (1hr)

Community level- fill and draw type

200-2000 poulation


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Community level- fill and draw type


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The picture shows Defluoridation Plant attached to Hand Pump.

CHEMICAL TANK

OUTLET

INLET

CHEMICAL DOSING SYSTEM

HAND PUMP

PERFORATED SHEET

GRAVEL

VALVE 1

VALVE 2

GRAVEL LANDBACK WASHLINE

MASONARY

M.S. STAND

DRAIN


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Indications for adopting Nalgonda

technique

Absence of acceptable, alternate low fluoride source within

transportable distance

Total dissolve solids below1500mg/l

Raw water fluoride ranging from 1.5 20mg F /l


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Salient features of Nalgonda technique

No regeneration mediaNo handling of caustic acids and alkalis

Domestic and community levels

Manual operated

Chemicals municipal water supplies

Cost effectiveFlexible design


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Combined Nalgonda and calcined

magnesite technique

In Tanzania (1985- 1990)

Nalgonda technique was passed thru a filter bed

consisting of calcined magnesite granules

Ph rise >10

Impractical for rural regions


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Prasanti technology 1998

Activated alumina

Bio-science dept, A.P

25 community defluoridation plants 200-

400people

500 domestic defluoridation plants

Cost effective


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Activated alumina


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Other materials tried in India

Fish bone charcoal university of Roorkee

Drumstick plant (ca, mg) reduce water turbidity

Askali extract mycetial biomass, Hyderabad

Clay minerals

Tricalcium phosphate


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References

Fluorides in dentistry Fejerskov

Fluorides Amrit tewari

Salt fluoridation - Adv dent res 1995

Dcna 1999

Essentials of preventive and community dentistry

soben peter

J of Indian dental association 1986

JDR 1992clinical uses of Fluorides- stephen wei

j dent child 1981

Documents

Systemic Flourides