• Magnitude of fluorosis
– World and India
• Epidemiological triad
• Permissible limits of fluoride
• Clinical picture and tests
• Treatment and prevention
• Community Fluorosis Index
• Methods for removal(De-fluoridation)
• Nalgonda technique
What is Fluorosis
• Fluorosis is a disease caused by
deposition of fluorides in the hard and soft
tissues of the body.
• It is not merely caused by excess intake of
fluoride but there are many other attributes
and variables which determine the onset of
fluorosis in human population.
• It is usually characterised by discoloration
of teeth and crippling disorders.
Magnitude of Fluorosis
• Worldwide in distribution
• Endemic in 22 countries
• Asia (India and China are worst affected)
• Mexico in North and Argentina in Latin America
• East and North Africa are also endemic
Geographical area with high
natural fluoride levels
• In some areas, skeletal fluorosis is endemic.
While fluorosis is most severe and widespread in
the two largest countries - India and China.
• UNICEF estimates that "fluorosis is endemic in at
least 22 countries across the globe. The total
number of people affected is not known, but a
conservative estimate would number in the tens
• WHO estimated that 2.7 million people
in China have the crippling form of skeletal
fluorosis. In India, 20 states have been identified
as endemic areas, with an estimated 60 million
people at risk and 6 million people disabled;
about 600,000 might develop a neurological
disorder as a consequence.(1999)
• Fluoride levels in surface waters vary widely
according to geographical location and proximity
to emission sources but are generally low,
ranging from 0.01 to 1.5 mg/L.
• Concentrations in seawater commonly range
from 1.2 to 1.5 mg/L. Freshwater concentrations
are usually lower than seawater ranging from
0.01 to 0.3 mg/L.
• Factor known to influence water fluoride levels
include the presence of natural rock rich in
fluoride (such as granites and sediment of
• Additionally, elevated inorganic fluoride levels
are often seen in regions where there is
geothermal or volcanic activity.
Fluorosis in India
• Fluorosis is an endemic disease prevalent in 20
states out of the 35 states and Union Territories
of the Indian Republic.
• Rajasthan and Gujarat in North India and Andhra
in South India are worst affected.
• Bihar, National Capital Territory of Delhi,
Haryana, Jharkhand, Karnataka, M.P. and
Maharashtra are moderately affected.
• T.N., W.B., U.P., Bihar and Assam are mildly
• Throughout India fluorosis is essentially
Hydrofluorosis except in parts of Gujarat and
U.P. where industrial fluorosis is also seen.
Fluoride: good or bad for
• Fluoride was first used to fight dental cavities in
the 1940s, its effectiveness defended on two
1.Fluoride inhibits enzymes that breed acid-producing
oral bacteria whose acid eats away
tooth enamel. This observation is valid, but some
scientists now believe that the harmful impact of
fluoride on other useful enzymes far outweighs
the beneficial effect on caries prevention.
2.Fluoride ions bind with calcium ions,
strengthening tooth enamel as it forms in
• Many researchers now consider this more of an
assumption than fact, because of conflicting
evidence from studies in India and several other
countries over the past 10 to 15 years.
• Nevertheless, agreement is universal that
excessive fluoride intake leads to loss of calcium
from the tooth matrix, aggravating cavity
formation throughout life rather than remedying
it, and so causing dental fluorosis. Severe,
chronic and cumulative overexposure can cause
the incurable crippling of skeletal fluorosis.
• Primarily it is Fluoride which is present in drinking
• When F in water is more than 1.5 mg/litre, it is
toxic to health
• pH in terms of alkalinity of water promotes the
absorption of F
• Calcium in the diet reduces the absorption of F
• Hard water rich in Calcium reduces the F toxicity
• Fresh Fruits and Vit.C reduces the effect of F
• Trace elements like Molybdenum enhances the
effect of F
Sources of fluoride for human
Main sources of fluoride :
• In School going children seen as dental fluorosis.
• In third and fourth decade of life seen as Skeletal
• Males suffer more than females.
• Migration influences the occurrence depending
on which way people migrate.
• Illiterates suffer more frequently in the fluorotic
• Where aluminium ores are mined,it is seen as
occupational health hazard.
• High Annual Mean Temperature
• Low Rainfall
• Low humidity
• Fluoride rich Natural subsoil rocks
• Vegetables from high F belts
• Fluoridated tooth paste particularly when used by
• Tropical climate
• Developing Countries
Permissible limit of Fluoride by
• Dental Fluorosis in Children
• Skeletal Fluorosis in Adults
• Non Skeletal Fluorosis
• Children living in high fluoride zone are bound to
get dental discoloration which may be seen even
in deciduous teeth.
• Initially glistening white teeth become dull and
yellow-white spots appear on the surface of
• Gradually these spots turn brown and presents
itself in brown streaks which are closer to the tip
of the teeth.
• In late stages the whole teeth become black.
Teeth may be pitted or perforated and may even
get chipped off.
• It affects young as well as old. The symptoms
include severe pain and stiffness in the
backbone, joints and/or rigidity in hip bones.
• X-ray examinations of the bones reveals
thickening and high density of bones. In some
patients with calcium deficiency, osteomalacia
type changes are seen.
• Constriction of vertebral canal and intervertebral
foramen - pressure on nerves leads to paralysis.
Radiograph of a patient
of skeletal fluorosis
• There are convincing evidence of involvement of
skeletal muscles, erythrocytes, G-I mucosa,
ligaments and spermatozoa on consuming more
than optimal intake of fluorides. Detection of
Fluorosis at early stage is possible by
understanding the soft tissue manifestation.
• In the fluorosed muscles, actin and myosin
filaments are destroyed and mitochondria lose
their structural integrity thereby providing
evidence of depletion of muscle energy.
• The erythrocyte membrane loses its calcium
content in presence of high fluoride.
• Non-ulcer dyspeptic complaints are manifested
by consuming high F in water and food.
• Infertility due to oligospermia and azoospermia is
commonly seen in fluorotic belts.
Tests for Skeletal Fluorosis
• Affection of the joints can be ascertained through simple
tests which can be carried out at the bed-head side and
in the field:
• COIN TEST: The subject is asked to lift a coin from the
floor without bending the knee. A fluorotic subject would
not be able to lift the coin without flexing the large joints
of lower extremity.
• CHIN TEST: The subject is asked to touch the anterior
wall of the chest with the chin. If there is pain or stiffness
in the neck, it indicates the presence of fluorosis.
• STRETCH TEST: The individual is made to stretch the
arm sideways, fold at elbow and touch the back of the
head. When there is pain and stiffness, it would not be
possible to reach the occiput indicating presence of
Dental Fluorosis Treatment
• Tooth whitening - For mild fluorosis cases.
• Composite bonding- For severe cases of fluorosis
• Porcelain veneers- provide excellent cosmetic
Prevention of Fluorosis
• Since the major source of fluoride is drinking
water, de-fluoridation is the best preventive
measure which can be carried out at domestic as
well as community level.
• Nutritional interventions like high intake of
vitamin C and Calcium also helps reduce the
Food items to be avoided
Black salt (Kala-namak)
Tea (without milk and with lemon)
Salted snacks smeared with black salt viz.
Dalmoth, Channa dal
Pickles smeared with black salt
Masala's smeared with black salt
Chana masala, Jal jeera masala
Fruit juices (Preserved)
Churans (Hajmola, Hingoli, Satmola)
Community Flourosis Index
• W.H.O. Monograph on Fluoride and Human Health
(1970) has enumerated the use of Community
Fluorosis Index in determining the optimal Fluoride
• The Community Fluorosis Index (CFI) is a way of
measuring the burden of dental fluorosis in a
population. Instead of measuring the overall
prevalence of fluorosis (i.e., what percentage of
people have fluorosis), it takes into account the
severity of the fluorosis that is occurring. The CFI is
thus a measurement of both prevalence + severity.
An individual's fluorosis score is based on the most severe form
of fluorosis found on two or more teeth.
Community Fluorosis Index
• The CFI is calculated based on the following point
scale for the different categories of dental fluorosis:
• Questionable Fluorosis = 0.5 points
• Very Mild Fluorosis = 1 point
•Mild Fluorosis = 2 points
•Moderate Fluorosis = 3 points
• Severe Fluorosis = 4 points
• After determining how many children have these
types of fluorosis, the points are added up and
divided by the number of children examined.
Scores and their significance
Range Significance of scores
3.0-4.0 Very Marked
Only when the CFI value is greater than 0.6,
Fluorosis is considered to be a public health
problem in that area
Methods for removal of Fluoride
• Bone charcoal,
• Contact precipitation
• Nalgonda technique,
• Activated alumina
•Methods based on
patented media and
• Boiling Water :This will concentrate the fluoride rather than
• Freezing Water: Freezing water does not affect the
concentration of fluoride.
Fluoride removal technologies and their suitability
• Precipitation methods are commonly used for de-fluoridation.
• Lime treatment, routinely used for hardness removal
can remove F particularly when water is having high
• Alum is used at domestic level in high doses to
remove the F.
• In India scientists have developed a method known
as Nalgonda technique in which, based on the
amount of F in drinking water and alkalinity of the
Water (expressed as mgCaCO3), amount of Alum to
be mixed with water is calculated.
• Adapted and developed in India by the National
Environmental Engineering Research Institute
(NEERI) and developed to be used at both the
community and household levels.
• The process is aluminium sulfate based coagulation-flocculation
sedimentation, where the dosage is
designed to ensure fluoride removal from the water
• Aluminium sulfate, Al2 (SO4)3 18H2O, is dissolved
and added to the water under efficient stirring in
order to ensure initial complete mixing.
• Aluminium hydroxide micro-floccules are produced
rapidly and gathered into larger easily settling
• Thereafter the mixture is allowed to settle. During
this flocculation process many kinds of micro-particles
and negatively charged ions including
fluoride are partially removed by electrostatic
attachment to the floccules.
The fill and draw type Nalgonda technique for domestic
and community defluoridation
• WHO Monograph “Fluoride in Drinking-water”(
• Central Ground Water Board(website)
• Bureau of Indian Standards(BIS)
• UNICEF report on Fluorosis in India(1999)