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Types of Topical Fluoride lect 5 Dr Raya Al-Naimi
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.
This procedure offered a method that was convenient to use and was
somewhat tolerated by patients.
Aqueous Solutions and Gels
Clinical studies comparing gels and solutions indicate that both are
the same order of clinical effectiveness with no obvious superiority of
gels over solutions, however application of aqueous fluoride using two
step prophylaxis and topical fluoride is a time consuming procedure .
Gel products have the same formulation of the aqueous solution but
with the addition of a gelling agent. A gel is an aqueous suspension of
organic or inorganic molecule that are arranged in a weak three
dimensional network producing a thickening or gelling of the entire
mass, by adding an organic hydroxyl methyl cellulose.
Advantages of Gel
1-Adhares to surface of teeth for considerable period of time
2-Eliminates the need for contiouous wetting of enamel surface
required by the operator
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3-Less time consuming because if trays are used ,it is possible to treat
2 or 4 quadrants simultaneously .
4-Hazards of accidently ingesting a large quantity of fluoride is
minimized .
Foams
In an attempt to minimize the risk of fluoride overdosage and to
maintain the efficacy of topical fluoride treatment , a foam based APF
agent has been developed ,the APF foam significantly increased the
fluoride concentration in the outer 5mm enamel, similar to that of APF
gel .
Advantages of Foam based APF agent
1-It is much lighter than conventional gel and therefore only a small
amount of the agent is needed for topical application (4gm of
gel/mouth while less than 1 gm of foam/mouth)
2-The surfactant in the foaming agent has a cleansing action by
lowering the surface tension ,this may also may facilitate the
penetration of the material in to the interproximal surface where its
action is most needed.
3-Since APF foam does not require suctioning ,it offers advantages for
home use as for treatment of young children and disabled persons
where saliva evacuation may not be feasible
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Methods of application of topical fluorides by dental professional
1. Paint on technique
2. Tray technique
3. Spray application has been tried in some experiments
In vivo and in vitro studies have demonstrated that fluoride uptake is
not reduced if the teeth are not scaled and polished .
Sodium Fluoride Solution and Gel NaF 2 %, 0.1 %
Concentration is usually 2%, the method of application proposed by
researchers was concluded that maximum reduction of caries at 4
application by weekly intervals at age of 3, 7 , 10 , 13 years to
concede with the eruption of the teeth .
The technique called Knutson tech. in which the first visit includes
prophylactic scaling and polishing and flossing to clean interproximal
areas then NaF is applied in quaderent after isolation and dryness by
air syringe ,application of solution by cotton pellet for 4 minutes for
every quadrent then instruct the patient not to eat or drink or rinse for
at least 30 minutes.
The other 3 visits , only fluoride solution is applied.The reduction in
dental caries by NaF range from 20- 40 % in permanent teeth in
children in non fluoridated areas, few researchers reported negative
results of application when used in adults.If the conc. Is 0.1 % the
application for 7 – 8 min.
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Advantages of NaF
1-Effective in reducing dental caries in children .
2-Used for sensitive teeth as desensitizing agent .
3-Taste is good .
4- Stable i.e no need to prepare it fresh.
5-Don’t give discoloration .
Disadvantages of NaF
1- Long procedure for application .
2- Not effective in adults .
3- Only effective in children living in non fluoridated area
Mechanism of effect :
Sodium fluoride affect as it react with calcium ions in the enamel to
form calcium fluoride on the tooth surface which in turn gives fluoride
ions that react with tooth structer and form flouroapitite which is more
resistant to dental caries.
Stannous Fluoride Solution 8 – 10 % SnF2
The method of application similar to sodium fluoride but in polishing
we use lavo pumice and application in quadrant ,it comes in form of
powder in small containers or in capsules which is then mixed with
water when prepared .It can be applied annually or every 6 months the
reduction in dental caries reported 38 – 61 %.
In child complaining from rampant caries it can be repeated every 3
months.By application of SnF a complicated agent will be formed.
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Ca10 ( PO 4 )6 (OH)2 + 19SnF2 10 CaF2 +6Sn3F3Po4 +
SnOH2O
Sn3F3Po4= Tinflouro phosphate ( complex agent )
SnOH2O = hydrated tin oxide
These 2 materials will be incorporated and react with the enamel surface
which are the fluoride and tin ions. The tin ion has a benefit of
remineralization (not easily disoluted )
Advantages of Stannous Fluoride
1- Arrest initial caries (white spot ).
2- More effective in reducing dental caries than NaF.
3- Used as a desensitizing agent in elderly patient .
4- Effective in child and adult .
Disadvantages
1- Not stable that undergoes hydrolysis and oxidation to stannous
hydroxide and stannous ions so it must be freshly prepared and
used .
2- It has a bad taste (metallic )addition of flavouring agents can cause
unfavorable reactions.
3- Causes gingival irritation .
4- Causes brown discoloration of teeth and around margins of anterior
restoration .
5- Nausea and difficulties in application in children .
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Acidulated phosphate fluoride APF 1.23% or 0.4%
Many reshearchers reported that as the pH was lowered fluoride was
absorbed in to enamel more effectively .If the PH = 4 ,their will be an
increase in the absorbtion of fluoride. PH lesser then 3 will cause
decalcification of the enamel .
There are two types of APF with carboxy methyl cellulose ,and the other
is thixotrophic (differ in the type of gel material) this is viscous at low
shear rate , converted to more fluid state at higher shear rate (less viscous)
so going to flow in between teeth.
Reduction rate of APF was 25 – 67 % in permanent teeth in non
fluoridated areas frequently every 6 months or annually depending on the
case.
Procedure
Scaling and polishing and flossing ,apply after isolation and dryness ,
fluoride gel applied in tray on the teeth after isolation ,instruct the patient
not to eat or drink or rinse for half an hour
30 minutes (application for 1 minute in new formulas ). It is more
recommended and widely used because it has less disadvantages and more
effective in reducing dental caries , the preparation has been tested using
self application procedure , also can be used in school based programmes .
In a study comparing the reduction rate of fluoride after 2 years
application on a daily basis in school and supervised by dental hygienist
80 % reduction with APF 75 % reduction with NaF
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Disadvantage
Not all the surfaces of the teeth especially the proximal surfaces have
been completely covered with fluoride .
Flouridated Mouth Rinses
Used in home or school preventive programmes having both systemic
and topical effect ,they are used in non fluoridated areas (no systemic
water fluoridation ) , it comes in different forms ( NaF , APF ) used either
on daily or weekly basis .
For daily use 0.05% (225 ppm ) in form of NaF or APF
Weekly use 0.2% (900 ppm ) in form of NaF or APF
For rinsing use 10 ml of the rinse solution for about 1 minute to push the
solution between the teeth and swishing it forcefully in mouth then to spit
it and not to rinse with water.
Flouride mouth rinse prescribed for :
1- Child with high risk to dental caries .
2- Patient with orthodontic appliance , also patient with partial denture
or bridge .
3- Adult with root caries or sensitive teeth .
4- Patient with xerostomia .
Not used for :
1-Children under 6 years of age .
2- Children given other fluoride supplement
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Flouridated Varnish
The longer duration and more intimate contact between fluoride ions
and enamel leads to a higher fluoride uptake by enamel , fluoride varnish
stick to the tooth surface to increase time of retention of fluoride with the
tooth surface , it was introduced in 1966 by Henser and Schmidt .A series
of varnishes containing fluoride in various form have been formulated as ;
Duraphate ( NaF 2.26 % )
Elmex protector ( Amine fluoride 297 )
Epoxylite 9070 ( disodium monoflourophosphate fluoride ) which is
incorporated in to a soft , flexible polyurethane based adhesive coating .
Duraphate
This fluoride varnish is suspended in an alcoholic solution of natural
varnish substance, which adhares to the teeth long enough to allow deep
penetration fluoride in to enamel and dentin , it is water tolerant so it
coveres even moist teeth with a well adharing film of varnish , and
hardens quickly in the presence of saliva .
Method of Application
1- The teeth should be thoroughly cleaned by rotating brush especially
sites most likely to be affected by caries .
2- The required quantity of Duraphate is then squeezed from its tube
in to a dappen glass or measuring cup and placed ready for use with
a cotton swab .
3- Dry teeth and apply varnish immediately with cotton swab , dipping
it repeatedly until the whole surface of tooth is covered evenly .
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4- To adhere of varnish to teeth , it must be moist with saliva in order
to harden .
After completing the painting it must be kept for 12-24 hours so
instruct the patient to take fluid diet and not to brush his teeth during
this period to avoid removal of film of varnish and allow maximum
penetration of fluoride .After the desired duration of action fluoride
varnish is removed by thorough brushing with a tooth brush .
Uses of Fluoride Varnish
1-General caries prophylaxis in children and adult .
2-Prophylaxis of caries in newly erupted teeth ( initial caries)
3-Prophylaxis of secondary marginal caries by painting the preparation
border after insertion of filling , inlays, crowns and bridges .
4-As desensitizing agent in treatment of hypersensitive necks of teeth .
Advantages of fluoride varnish:
1-There is less fluoride ingestion with a fluoride varnish than with
conventional office caries treatments because the fluoride adheres to the
tooth surface for longer periods of time.
2-Duraphat releases fluoride for 28 weeks. Two-thirds of the fluoride
is released by 6 months
3- No special equipment is needed for the application.
4-Teeth do not need to be professionally cleaned prior to varnish
application.
5-Children can eat and drink immediately after application.
6-You can leave immediately after application. There are no fluoride
trays which prevents gagging.
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Fluoridated Dentifrices
Fluoridated dentifrices are considered the most cheapest and easiest way
of bringing the benefits of fluoride to population,. 95 % of all toothpaste on
sale contain a fluoride compound , a major problem in manufacturing
fluoridated toothpaste is preventing the fluoride from reacting with other
ingredients especially the abrasive system ( calcium carbonate and calcium
phosphate ).
There were about eight early studies using a combination of sodium
fluoride with calcium abrasive systems, with none of these studies resulting
in significant reductions in dental caries. The most likely explanation was
the incompatibility of the abrasive system with the sodium fluoride active,
since it could react with the calcium of the abrasives and form calcium
fluoride. Calcium fluoride is not reactive with the enamel surface, and this
lack of reactive ionic fluoride most probably resulted in the failure of these
early formulations to prevent caries. In 1954, the first report of a clinically
effective fluoride dentifrice was made. This dentifrice contained stannous
fluoride combined with a heat-treated calcium phosphate abrasive system.
This SnF2–Ca2P2O7 combination was provisionally accepted by the ADA's
Council on Dental Therapeutics with category B classification in 1960.17
Upon completion of additional studies showing its therapeutic effect, the
dentifrice was given a category .
In 1981 they replaced it with NaF with an abrasive of silicon dioxide
marketed as crest + .
Other researchers used sodium monofluorophosphate instead of NaF.
Sodium monofluorophosphate is superior to other types of fluoride from a
compatability point of view with abrasive.
The concentration of fluoride used in dentifrices range from( 525 – 1450 )
with an average of 1000.
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Fluoridated Prophylactic Paste
Fluoride has been incorporated in to prophylactic pastes to try to
maintain a high concentration in the enamel surface and to determine
whether in combination with topical fluoride application an additional
caries inhibitory effect can be obtained.
The following agents have been incorporated in to prophylactic pastes
NaF, SnF2, APF, Sn haxa fluorozirconate.
Lavo pumice was used with SnF2 because it is more compatable
chemically and has a superior cleansing effect.
New compound Sn haxa fluorozirconate was used and reported to be
effective in reducing acid solubility of enamel and reduce dental caries ,
but some researchers reported toxic reactions as irritation and subsequent
inflammation of gingival occurred and in extreme cases necrosis of soft
tissue occurred.