improtan

1. The role ofThe role of
fluoride in cariesfluoride in caries
prevention,prevention,
toxicologictoxicologic
aspectsaspects
12th lecture12th lecture

2. Goals of Fluoride (F)Goals of Fluoride (F)
AdministrationAdministration
• 1) Do not harm the patient.
• 2) Prevent decay on intact dental
surfaces.
• 3) Arrest active decay.
• 4) Remineralize decalcified tooth
surfaces.

3. GOALS OF FLUORIDE (F) ADMINISTRATION
Do not harm
Prevent decay on intact
dental surfaces
FF
FF
Arrest active decay
Remineralize
decalcified teeth
1.
2.
3.
4.
FF
Fluorosis or
toxicity

4. The Basics of FluorideThe Basics of Fluoride
PreventionPrevention
Ca10[PO4]6 [OH ]2+F-
= Ca5[PO4]3 F Ca5[PO4]3 OH +OH-
equation
Hydroxyapatite (HAP) Fluorhydroxyapatite (FHA)

5. OH
PO4
Ca
Ca
Ca
Ca
Ca Ca
PO4
PO4
PO4PO4
OH
PO4
Ca
Ca
Ca
Ca
Ca Ca
PO4
PO4
PO4PO4
OH
F-
F-
Hydroxyapatite (HAP) Fluorhydroxyapatite (FHA)

6. If more fluorid ingested during enamel formation:
Ca10[PO4]3 [OH ]2+20F-
= 10CaF2 +PO4
3-
+ OH-
With the breakdown of HAP crystals calciumfluoride is formed.
Clinical appearance: White - Brown spots on teeth.
Fluorosis
Fluorosis, regardless of severity, cannot occur once enamel
formation is complete and the teeth have erupted. Therefore
older children and adults are not at risk for dental fluorosis.

7. Benefits of fluorideBenefits of fluoride
• Increased resistency against acides
• Compact cristall-net
• Pre-eruptive effect: different shape
(shallow fissures and smaller cusps)
• Post-eruptive effect: remineralisation,
inhibition of sugar-digesting enzymes,
inhibition of polysaccaride-synthesis in
high cc, inhibition of protein (bact)
absorption to enamel surfaces, inhibition
of regeneration and colonisation of
cariogen bacteria.

8. General effectsGeneral effects
• Inhibition of arteriosclerosis
• Inhibition of osteoporosis

9. Toxicity of swallowed TPToxicity of swallowed TP
• STD (safely tolerated dose) – 1-3 mg
/bwkg
• PLD (potentially lethal dose) – 5mg /tskg
– PTD (potentially toxic dose)
• CLD (certainly lethal dose) – 32-64
mg/tskg

10. Probable toxic dose (PTD): 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
mouthrinse contains 91 or 97mg F and a tube of
fluoridated toothpaste contains as much as 230mg
F.
TEXT

11. POTENTIAL HARM
5 mg F / kg body5 mg F / kg body
weightweight
20 kg 6 year old,
PTD= 100 mg F100 mg F
10 kg 2 year old
PTD = 50 mg F50 mg F
230 mg230 mg F/
tube
toothpaste
ACT
91-97 mg91-97 mg
F/
container
of F
mouthrinse
Symptoms:Symptoms:
1.1. VomitingVomiting
2.2. Excess salivaryExcess salivary
and mucousand mucous
dischargedischarge
3.3. Cold wet skinCold wet skin
4.4. Convulsion atConvulsion at
higher dosehigher dose
Probable toxic dose:
Topical F,
12,300 ppm
F pH= 3.5
61.561.5
mgmg F/
5 ml

12. FF
CaCa
FF
CaCa
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.
FF CaCa
FF
CaCa
FF CaCa
FFCaCa
FF
CaCa
FF
CaCa
A serious systemic
consequence is
binding of F to Ca
which needed for
heart function.
POTENTIAL HARM
FF CaCa
FFCaCa
FF
CaCa
FF
CaCa

13. ToxicityToxicity
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.
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.)

14. ToxicityToxicity
• Chemical burn: concentrated F
contaminated with skin, creates HF
acid
• Protoplasma toxicity: inhibition of
enzyme-systems
• Binding Ca: inhibitors of muscle
function
• Hyperkalaemia (extra high potassium
level): cardiotoxicity

15. Chronic toxicityChronic toxicity
• Sceletal fluorosis
• -osteosclerosis
• -calcification of tendons
• -multiplex exostosis

16. Chronic toxicityChronic toxicity
•The
fluorosis

17. Fluorosis: 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.
TEXT

18. FLUOROSIS
FF
FF
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

19. 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 F
1.2 ppm
water F

20. 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
recommended for fluorosis
susceptible children.

21. moderate
severe
mild
pitting

22. Mild fluorosisMild fluorosis

23. Moderate fluorosisModerate fluorosis

24. Severe, pitted fluorosisSevere, pitted fluorosis