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Community water fluoridation lect 4.Dr Raya Al-Naimi
Defined as the upward adjustment of concentration of fluoride ions in the
public water supply in such a way that the concentration of fluoride may be
constantly maintained at 1 ppm , this is the optimal level of fluoride were the
hydroxy apitite crystals during the tooth formation will become flouroapitite
when systemic fluoride is taken and enamel surface becomes more resistant
to acid attack.
Advantages of water fluoridation
1. It is effective in reduction of dental caries 50 – 60 %.
2. It is safe.
3. Low cost.
4. Its ease of implementation.
5. the benifits of fluoride reaches to the entire population.
6. No cooperative effort is required by individual other then consuming
water supplies .
7-Saving human suffering toothache
School Water Fluoridation
The school water fluoridation has been tested in areas with out
community water fluoridation, the level of fluoride in school water varies
between (2.2 – 5 ppm) ,these levels were chosen because children have
only part of their daily water intake at schools, in addition to the reason
that they do not attend school all year round ( holiday ) and they enter
school at the age of 6 years (central incisors and permanent first molars
have erupted or soon to erupt, so that there is no fear from flourosis)
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Advantages
1. It is effective ( reduce dental caries ) 35 – 40 % reduction.
2. Safe .
3. Reaches large number of children .
4. Low cost /person / year $1.5
5. Simple and can be done by non dental personal.
6. Accepted by child .
7. Technically feasabile.
8. No effort required by children other than consuming water in
school.
Disadvantages
1. The child doesn’t receive the benefit of fluoride until he begins school
i.e 6 years of age.
2. Consumption of water is only when school is in session .
Flouridated Salt
Addition of F to salt is considered an efficient way of bringing the benefits
of systemic fluoride to whole population when there is no piped water
supply.
Flouridated salt has been on sale in Switzerland since 1955 and by 1967
three quarter of domestic salt used in Switzerland tables was fluoridated by
90 mg/kg salt (conc. 90 ppm ), in more recent investigation the levels of
fluoride has been raised to 350 mg F/ kg salt in order to increase effectivness
in reducing dental caries , it is effective although it appears to be slightly less
than observed with water fluoridation, no effort by consumer is required ,
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easy application, low cost , has been found to reduce dental caries in
primary and permanent teeth but with disadvantages:
1. Amount of salt intake vary between individuals.
2. Infants do not start administration from birth .
Flouridated Milk and Fruit Juice
Because milk is recommended as a good food for infants and children , it
has been considered as a suitable way for supplying children with fluoride in
areas with out fluoride in water.
Adding fluoride to liquid, powdered, and long-life milk has been
implemented in Eastern Europe, China, the UK, and South America. It has
the advantage over water fluoridation in that it can be targeted directly at
certain segments of the population, and intake can be controlled.
Fluoridated milk is given under supervision in the school in order to control
the amount of milk given to the child, the conc. Of F in milk is 1 – 1.5 ppm ,
some researchers found contraversal results saying the protein and calcium
in the milk will only retard or delay absorption of fluoride in stomach and
may even prevent the topical effect of F milk ( protein form a layer on the
tooth that prevent the effect of F )
Fluoridated juice may be used as an alternative to fluoridated milk , in a
study reported a reduction rate of 35% in DMFS for permanent teeth in 6 – 9
year olds children when they consumed 1 mg F in 100 ml of pure orange
juice (10 ppm ) used in each school day for 3 years .
Flouride Tablets and Drops
Flouride tablets or drops ingested from shortly after birth until the age of
16 years can provide protection against dental caries ranging from 50 – 60
%, there is a variation in the dosage recommended for the tablets, it depends
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upon the age of the child and the conc. Of the fluoride in the drinking water ,
in addition to the presence or absence of other fluoride supplements.
Fluoride tablets must be chewed then swallowed ( topical + systemic effect )
Age F. conc.water <0.3 0.3 – 0.6 >0.6
Birth – 6 months non non non
6 months – 3 y 0.25 0 0
3 y -6 y 0.5 0.25 0
6 y -16 y 1.0 0.5 0
ADA councel on scientific affairs recommendations
New dosage schedual approved (ADA 1994 )
Fluoride tablets are found in the form of sodium fluoride NaF, calcium
fluoride CaF2, or acidulated phosphate fluoride.
Many reports are found on the effectivness of F tab. Or drops , they fell in to
two groups.
1. Those where the fluoride supplements was given at home and was
started before school age .
2. Those when F tab was given on school day usually without additional
supplements of F during holiday or before school age .
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The percent caries reduction in primary teeth was greater in children whose
mother received F tab in pregnancy, when F tab used pre and post natally
there was greater caries reduction in dental caries in primary teeth than used
only post natally , there was no benefit to permanent teeth when used
prenatally.
The primary teeth are formed and calcified in the uterus (placenta
regulate the amount of F passing in to the child )
The use of F tab require cooperation of the parents and child and a high level
of parental motivation and campaigns to get parents to give their children F
supplements , some times there unsuccessful , so it is preferred to give these
supplements in school based programmes .
Halo Effect of Water Fluoridation
The first community water fluoridation studies, which were begun in
the mid-1940s, demonstrated that reductions in childhood dental
caries attributable to such fluoridation were approximately 50%–60%.
More recent estimates of such reductions are lower, at 18%–40%.
This decrease in attributable benefit comes from the increasing use of
fluoride from other sources, of which the widespread use of fluoride
toothpaste is probably the most important.
The diffusion or "halo" effect of beverages and food processed in
fluoridated areas, but consumed in nonfluoridated areas, also
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indirectly spreads some benefit of fluoridated water to nonfluoridated
communities.
This effect lessens the differences in caries experience between
communities.
When a parent feeds a child
reconstituted with fluoridated
water, they are exceeding the fluoride dosage recommendations of the
(ADA). According to the ADA, infants under
6 months of age should receive NO fluoride supplementation, while infants
between the age of 6 months and 3 years should receive no more than 0.25
milligrams per day. Ingestion of fluoridated infant formula will exceed these
limits and significantly increase the child's risk of developing dental
fluorosis
Distribution of fluoride to the fetus
There are different views regarding passage of fluoride across the placenta
some author have said that placenta acts as a complete barrier to fluoride,
others have said it is only partial .According to a study it act as a barrier
when there is a sudden increase in maternal plasma fluoride level,the fact
that primary dentition exhibits less sever degrees of fluorosis then
permanent dentition indicates the presence of some form of placental barrier
or regulator .
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Rational for using topical fluoride agents
Over a period of few years the concentration of fluoride at the enamel
surface increase above the initial concentration of the eruption time ,this is
due to the uptake of the fluoride by the enamel present in the salivary
environment and this in turn by the fluoride concentration ingested from
water and foods, this process may be viewed as a continuation of the
maturation process and is important as a defense contribution against enamel
caries , so the rational for using topical fluoride is to speed rate and increase
the concentration of fluoride acquisition over the level which occurs
naturally ,if an individual is exposed post eruptively it may take years
before surface enamel acquires an effective concentration, topical fluorides
hastens this process, since immature and porous enamel acquires fluoride
rapidly and since erupted teeth undergo a rapid maturation so the best time
to apply topical fluoride is soon after eruption ,also the initial caries lesion ,
is characterized by white spot which is porous and accumulates fluoride at a
much higher concentration than the adjacent sound enamel .This implies
that periodic application would enable vulnerable enamel sites that are
partially demineralized to accumulate fluoride .
Types of topical flouride
1- Flouride gel and solution lozenges and foams.
2- Flouride mouthrinse.
3- Flouridated varnishes .
4- fluoride dentifrices .
5- Flouride prophylactic paste .
For many decades the professional fluoride method included a
disposable mouth tray with a 1.23% APF gel or a 2% sodium fluoride.
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This procedure offered a method that was convenient to use and was
somewhat tolerated by patients. However, sodium fluoride varnish is
recommended as the standard of care for children by both the AAPD and
ADA. There are several reasons, such as patient compliance, the higher
ppm of fluoride in varnish (22,600 ppm), and the ability to place it
intraorally in any setting.