4. Fluoride is a mineral that occurs naturally in all water sources, including the oceans. Research has shown that fluoride not only reduces cavities in children and adults, but it also helps repair the early stages of tooth decay, even before the decay is visible. Fluoride is the best cavity fighter to help keep the whole family's teeth strong no matter their ages.

5. FLUORIDE AND FLUORIDATION Despite great improvements in the oral health of population across the world, problems still persist. Caries remains a relatively common yet largely preventable disease of childhood that is not self-limited affecting 60-90% of school children & the vast majority of adults (WHO report).

6. FLUORIDE AND FLUORIDATION The incidence of dental caries will increase in many of the developing countries, in the light of changing living conditions & dietary habits. The principal reasons for this increase are growing sugar consumption & inadequate exposure to fluorides.

7. Occurrence and Intake:- Fluoride is a trace element & belongs to the halogen group. Fluoride enters the atmosphere by volcanic action and returns to the earth's surface by deposition as dust, rain, snow It is the most electronegative & reactive of all these elements.

8. It occurs rarely in the free state in nature,but mostly in the form of inorganic fluoride episodes, fluorspar CaF2 or fluorosilicates Na2 SiF6 In biologic mineralized tissues such as bones and teeth, it occurs as a mixed salt, not as pure fluoroapatite. Fluoride concentration in ground H2o is limited to 0.2 to 2 ppm.

9. In rivers it may range from 0.1 to 1.0ppm. Seawater from 1.2 to 1.4 ppm of fluoride. Tea leaves are rich source of fluoride. Sea food may contain 2.5 ppm. Most vegetables,fruits & dairy products contain less amount of fluoride.

10. Caries prevention by fluoride (anticaries agent)is based on attempts to increase host resistance to decay & to remineralize partially demineralized tooth structure. Enamel is exposed to a wide range of therapeutic levels of fluoride, ranging from as low 000.7-1.2 fluoride in optimally fluoridated H2O supplies to as high as 22.600 ppm in provisionally applied fluoride varnishes.

11. What are the common sources of fluoride? Toothpaste (if swallowed by young children). Drinking water in fluoridated communities. Beverages and food processed with fluoridated water. Dietary prescription supplements that include fluoride (e.g., tablets or drops). Other professional dental products (e.g., mouth rinses, gels, and foams).

12. Source of fluoride Toothpaste enhanced with fluoride Fluoridated water supplies Mouthwash enhanced with fluoride Food processed with fluoridated water Fluoride supplements

13. Mode of action of fluoride:- 1) Increase Resistance of tooth structure to Demineralization : Fluoride has strong affinity for apatite crystals, if fluoride interacts with the mineral phase; it fits more perfectly into the crystal than do hydroxyl ions. It adsorbs onto the surface of barrier against acid dissolution of the crystal forming a more stable & lesssoluble crystal thereby inhibit demineralization

14. 2) Enhancement of the process of Remineralization:- Fluoride ions have great affinity for demineralized regions. When the PH falls during a cariogenic challenge, the coating dissolves and the calcium and fluoride ions are free to contribute to re-mineraliztion and prevent further demineralization.

15. During remineralization calcium ions are regained & fluoride ions accelerate this process. Repeated cycles of acid challenge, followed by a PH rise, combined with frequent access to fluoride will result in so called 2ry maturation & the tooth enamel will gradually become more caries resistant.

16. 3)Bacteria are subjected to several fluoride inhibitory effects such as: 1- Inhibition of growth due to production of hydrofluoric acid. 2- Bactericidal effects. 3-Inhibition of bacterial metabolism by decreasing the amount of acid production.

17. ClinicalImplications of Fluoride : Maximizing the benefit and minimizing the risk Maximize anti-caries efficacy. By the presence of fluoride in oral cavity as long as possible (Concentration & frequency of application) Fluoride in Caries Prevention: Fluoride therapy is considered under 2 main headings: 1)System Fluoride 2)Topical Fluoride

18. Preventive services may be provided for the :- 1-community 2-Individual

19. 1-Community Preventive services : Communal water fluoridation is considered by many countries to be the ideal caries prevention program. The cost benefits are impressive & the value of teeth saved from extraction is even more important. An optimal level of fluoride in the water supply provides significant protection against caries, yet entails minimal risk of fluorosis. The optimal conc. depends on the annual average,maximum daily temperature in the community.

20. 2- School water fluoridation : It is one of the primary preventive services used by community where there is no fluoridation of public water. The recommended amount of fluoride is 4.5ppm (exposure is only during school days & school hours). The decrease in Caries index is about 40% with no evidence of dental fluorosis By age 6y,all teeth except the third molar are in advanced staged of mineralization thus reducing the pre-eruptive Benefits of fluoride.

21. 3-Fluoride supplement programs: Where water fluoridation is not feasible, fluoride supplements offer our optional source of systemic Fl. They are available in the form tablets, lozenges, drops. They have proven to be effective cariostatic agents, provided they are taken on a daily bases from 2 to about 16 y of age. The fluoride dose is adjusted according to the age of the child & the fluoride level in water supply.

22. 4-Fluoride Mouth Rinse Programs: It is one of the most widely used caries prevention public methods. Trials have shown that rinsing daily, or weekly with dilute solutions of fluoride reduce caries incidence by 30% Not be used by children from 7-14 years due to risk of swallowing excessive F.

23. 5- Salt Fluoridation: Fluoride-based Preventive Services Delivered to the Individuals: A- Professionally applied B- Self applied (nonprofessionally applied)

24. A-Professional Topical Fluoride Application: It refers to applying large concentration of fluoride (9000-25.000ppm)that’s locally to erupted tooth surfaces. This term includes: Solutions, gels, pastes, foams, varnishes. Caries inhibition by these topical applications is nearly 30%

25. 1-Fluoride Solutions: Three high-potency topical fluoride systems have been approved: - Sodium Fluoride 2.0 Na F 9000ppm (0.9% Fluoride). - Stannous fluoride 8% Snf2 20.000-25.000ppm - Acidulated phosphate fluoride 1.23% (Na F + hydrofluoric acid)

26. 2-Fluoride Gels : - Their viscosity makes them easier for application. - The concentration of fluoride in gel typically ranges from 5000 ppm to 12300ppm.it has a viscous texture which allows its professional application in a tray, with cotton wool or with dental floss.

27. 3-Fluoride Foams: They are developed to overcome the risks associated with using high potency fluoride products. The advantage of foam products is that 75% less FI is needed this reduces the risk of acute FI toxicity.

28. 4-Fluoride Varnishes : They are non-aqueous solutions that are painted on the teeth to prolong fluoride exposure, their rapid dryness prevent ingestion & minimize the risk of toxic dose. Convenient to use for :  Children & adults at risk of dental caries.  Special health care needs.  To target a specific teeth.

29. B- Non-Professional Topical Fluoride Application (Home-based methods of delivery):  Self Applied Fluoride Products: 1.Fluoride mouth Rinses: - Home use of fluoride rinses is indicated for patients who are caries active, for orthodontic patients with reduced salivary flow. - Not recommended for children under 6years of age - Reports indicate that they reduce caries by 30%-35%

30. 2-Fluoride Gels: - They are designed for daily use. They are about 40% of the concentration of fluoride used for professional office (1000 - 5000ppm) - They are either brushed on the teeth (1mm) or used in custom trays (5mm). - They are not recommended for children under 6 years of age. 3-Floridated tooth picks & Dental Floss

31. FLUORIDE TOXICITY fluoride can have both beneficial and detrimental effects on the dentition The beneficial effects of fluoride on dental caries are due primarily to the topical effect of fluoride after the teeth have erupted in the oral cavity. In contrast, detrimental effects are due to systemic absorption during tooth development resulting in dental fluorosis

32. Metabolism of fluoride FL is absorbed by passive diffusion from both the stomach & the intestine as a weak acid (HF). Excretion is mainly by the kidneys. Fl conc. In saliva ranges from 0.01 to 0.04 ppm. Concentration in plaque ranges from 50 to 100 times higher than in whole saliva.

33.  Acute fluoride toxicity The acute toxic potentials of fluoride compounds are related to their ionizability. The active to toxic potential of fluoride in MFP(Sodium Monofluorophosphate)is about half that of NaF.

34. Fluoride acts in four general ways: 1- Enzyme inhibition. 2- calcium complex formation (hypocalcaemia) 3- Hyperkalemia cardio toxicity.

35. Probable Toxic Dose (PTD): Is the minimum dose that could cause signs & symptoms including death PTD is symptoms 5 mg F/kg.

36. Certainly Leathal Dose(CLD) It is the amount of fluoride that will result in patient death if timely interception by antidote is not initiated CLD : is 5-10 gm of sodium fluoride taken at time CLD: 32-64 mg F/KG CLD IS 4 times STD

37. Safely Tolerated Dose (STD ) It is the amount of fluoride that can be ingested without causing symptoms of serious acute toxicity It is usually one fourth of CLD Adult STD : 1.25-2.5 gm (1000 mg) of Sodium Fluoride ( 8-16 mgF/kg) Children : less than 1 gm(1000mg) is fatal in children 12 years & younger, & 1/5 gm (500 mg) for children under 6 years of age is lethal

38. Symptoms of acute toxicity  Minor symptoms Nausea, vomiting, abdominal pain, hyperactive reflexes.  Sever symptoms Clonic convulsions cardiac failure the onset is rapid 1-24 hours death

39. Treatment of acute toxicity Aimed to reduce amount of flouride absorption 1 - induce vomiting 2-give milk or calcium drink 3-hospital administration

40. Chronic fluoride toxicity A- Skeletal fluorosis : accumulation of FL leads to pathological bone formations, calcification of tendons, (H2O FL level > 14 ppm )

41. B- Dental Fluorosis What does dental fluorosis look like? Very mild and mild forms of dental fluorosis— teeth have scattered white flecks, occasional white spots, frosty edges, or fine, lacy chalk- like lines. These changes are barely noticeable and difficult to see except by a dental health care professional. Moderate and severe forms of dental fluorosis—teeth have larger white spots and, in the rare, severe form, rough, pitted surfaces.

42. Who develops dental fluorosis? Only children aged 8 years and younger can develop dental fluorosis because this is when permanent teeth are developing under the gums. Once the teeth erupt through the gums and are in the mouth, they can no longer develop fluorosis. The teeth of children older than 8 years, adolescents, and adults cannot develop dental fluorosis.

43. Treatment of dental fluorosis -. Fluoros is affects only the appearance of teeth. It does not result in cavities. As a result, most of the treatment for fluorosis consists of masking the stain. -More serious cases and cases involving the front teeth can be treated by removing the surface-stained areas through tooth whitening or other procedures. - Severe cases of fluorosis can be covered with bonding, crowns or veneer s