GOALS OF FLUORIDE (F) ADMINISTRATION

1. Endogenous prophylaxis of teeth caries at children. Testimony, facilities, mechanism of action, method of application

2. GOALS OF FLUORIDE (F) ADMINISTRATION 1. Do no harm 3. Arrest active decay F Fluorosis or toxicity 2. Prevent decay on in tact dental surfaces 4. Remineralize decalcified teeth F F

3. TEXT Do not harm the patient 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. 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.) 1.

4. POTENTIAL HARM Probable toxic dose: 5 mg F / kg body weight 61.5 mg F/ 5 ml 91-97 mg F/ container of F mouthrinse ACT Topical F, 12,300 ppm F pH= 3.5 20 kg 6 year old, PTD= 100 mg F • Symptoms: • Vomiting • Excess salivary and mucous discharge • Cold wet skin • Convulsion at higher dose 230 mg F/ tube toothpaste 10 kg 2 year old PTD = 50 mg F

5. POTENTIAL HARM A serious systemic consequence is binding of F to Ca which needed for heart function. • Counter Measures: • Emetics • 1% calcium chloride • Calcium gluconate • milk F F F Ca F Ca Divalent cations like Ca cause precipitation, of F and prevent absorbtion in the intestine. Ca Ca F F F F Ca Ca Ca Ca Ca Ca F F F F Ca Ca

6. TEXT Do Not Harm the Patient 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. 2.

7. POTENTIAL HARM DMFT FLUOROSIS 10 9 8 7 6 5 4 3 2 severe moderate mild slight 0.0 0.5 1.0 2.0 3.0 4.0 PPM F IN DRINKING WATER F in excess of 0.1mg/ kg body weight = fluorosis

8. FLUOROSIS F F Enamel prism Excess F affects mineralization of developing teeth Up to age 6 is the critical age for fluorosis. After age 8, risk is past.

9. FLUOROSIS Daily F intake of a 20 kg 4 year olds with different water F Maxium safe dose for a 2 year old = 1 mgF / day 1 2 3 4 mg F 0.5 ppm water F 1.2 ppm water F supplements toothpaste Maxium safe dose for a 5 year old = 2 mgF / day fluids food F in excess of 0.1mg/ kg body weight = fluorosis DW Banting JADA 123:86,1991

10. FLUOROSIS 5 year olds swallow 25% of toothpaste Children under 2 years swallow 50% of toothpaste 1 to 3 grams Toothpaste = 1 mg F / gram (1000 ppmF) “pea” size amount (0.5g) is recommenred for fluorosis susceptible children.

11. mild moderate pitting severe

12. TEXT Prevention of Caries Deposition of fluorapatite (FHA) in sound tooth structure: Caries protection results from FHA being more acid resistant than pure hydroxyapatite (HA). Deposition takes place when F replaces hydroxyl groups in HA. This can occur pre- or post-eruption at neutral pH, or post-eruptively at neutral or acidic pH. At low pH, HA dissolves, then re-precipitates as new crystals which are larger and more acid-resistant due to higher FHA and lower magnesium and carbonate content. Deposition of FHA is accomplished both by systemic intake of F during tooth development, and topical F administration after eruption. Professional topical F treatments with concentrated acidulated phosphate fluoride (APF) gels (2.72% APF gel contains 12,300 ppm F), is the most efficient way to accomplish this, especially when applied to newly erupted teeth (i.e., age 2 for primary molars; age 6 to 8 for permanent first molars and anterior teeth; age 11 to 14 for permanent premolars and second molars). 1.

13. MECHANISMS OF F PROTECTION DEPOSITION Saliva (S) F F F F F Plaque (P) F F F F F F F Tooth (T) Topical F is the best method for deposition. Theory: Increase FHA levels maximally in intact dental surfaces.

14. DEPOSITION OF F F FHA is more acid resistant than HA F F F F FHA Neutral pH H+ PO4 H+ F PO4 FHA F F HA F CO3 Ca Ca pH 5.0 Mg F H+ Mg and CO3 do not repreci-pitate P H+ Ca FHA remineralization

15. DEPOSITION OF F Best F uptake is late pre-eruption and early post-eruption Surface build-up of F F F F F F F F F F F F F Mature enamel F F F Enamel fluid F F F F Young enamel This has better F uptake due to more porosity Maximal F levels of in outer 5 microns

16. DEPOSITION OF F Fluoride uptake is higher in a decalcified area PPM Fluoride 3000 2000 1000 5 um 3000 ppm F 1500 ppm F outer 2 microns = 6000 ppm fluoride (max. uptake) F F F F Ca Ca Ca Ca Ca As fluoride reacts strongly with calcium it does not penetrate far into the tooth.

17. DEPOSITION OF F: F Maxium uptake can not be exceeded. (3000 to 4000 ppm F in outer 5 um) The F-rich surface can be abraded away.

18. Caries reduction TOPICAL F STUDIES 100% Averill JADA 74:990,1987 DePaola JADA 87:155,1973 Downer BritDJ 141:242,1978 Horowitz JDent Child 27:157,1980 Muhler JDent Child 27:1571980 Szwejda JPub Health Dent 32:110,1972 NaF APF APF SnF2 SnF2 APF Newly erupted teeth Previously erupted teeth

19. TEXT Prevention of Caries Bioavailability of F: A second theory of caries prevention asserts that F in the vicinity of carious activity (in enamel fluid) prevents dissolution of HA crystals. Although this mechanism requires only low levels of F (less than 100ppm to as low as 1ppm), F must be present when the acid challenge takes place and therefore must be supplied continually. Examples of topical applications which ensure bioavailability are fluoridated drinking water and fluoridated dentifrices. A major source of bioavailable F is residual F in plaque and pellicle. F in plaque minerals such as CaF2 or calculus or in protein complexes is released during bacterial acid production. 2.

20. MECHANISMS OF F PROTECTION BIOAVAILABILITY Water fluoridation is an example of a source. S F SUGAR P F ACID F T Theory: Provide continual low level of F to enamel fluid. The benefit occurs at the time of decalcification.

21. BIOAVAILABILITY OF F Decalcification of enamel crystals: S SUGAR Low level of F F saliva H+ S S plaque F F H+ F Decalcifying HA crystals Plaque and enamel fluid F H+ H+ F H+ Intact HA crystals J Arends. JDR 69(SI):601,1990

22. BIOAVAILABILITY OF F F from plaque fluid J Arends. JDR 69(SI):601,1990 ACID F F F H+ F F F F F H+ F F F F F F Protection from dissolution Loosely-bound F will eventually become stable FHA. F Stable FHA Loosely bound or adsorbed F F

23. BIOAVAILABILITY OF F H+ FHA with no F F H+ H+ H+ F F H+ F F PO4 F F F PO4 F H+ H+ H+ Ca F H+ Ca Protection only where is H+ F Incomplete protection J Arends. JDR 69(SI):601,1990

24. BIOAVAILABILITY OF F Effect on bacteria: H+ F S S F F F H+ H+ F H+ H+ F F MS H+ F The presence of fluoride at the time of glycolytic activity will also inhibit of plaque acidogenesis. H+

25. SOURCES OF BIOAVAILABLE F 1. saliva ACT 2. Fluoridated water 3. Home care products 4. RESIDUAL F Topical F F F F F F S ppm F in saliva after drinking P F 0.08 0.02 F F F T Calcium Fluoride 1 3 5 h CaF2 precipitates in plaque during topical F treatment

26. BIOAVAILABILITY VERSUS DEPOSITION OF F Rodent studies: LESIONS (mean) 30 No FHA MS plus 8 DEPOSITION FHA F F 5 sugar BIOAVAILABILITY No FHA 10 ppm F added to drinking water Larson RH. Caries Res 10:321, 1976

27. BIOAVAILABILITY OF F Research evidence: Add F: F calcium loss F HA pH 5.0 5 4.5 4 pH phosphate calcium F ppm in solution JM Ten Cate. JDR 69(SI):614,1990

28. TEXT Prevention of Caries Summary of preventive F procedures and recommendations: The older view of caries prevention was that FHA deposition in non-carious dental surfaces should be maximized by systemic F administration during tooth development, and post-eruptively by topical F treatments. It was believed that increased FHA provided increased protection against caries. Although implementation of high FHA deposition has proved beneficial, it does not afford as much protection as bioavailable F. Moreover, the high doses of F required, systemically or topically (which often becomes systemic intake) are partly responsible for the increasing incidence of fluorosis. Current clinical recommendations for preventive F measures are 1) to determine total F intake per day from all sources in order to assess over or under F exposure, 2) determine caries risk, 3) institute a regimen commensurate with individual caries risk status which emphasizes bioavailability of post-eruptive topical F (e.g. regular use of F dentifrice and other home products if indicated), 4) administer professional topical F treatments, the timing of which should also be gauged to caries risk (This may not be needed in low risk individuals) and 5) administer systemic topical F if indicated. (The latter is currently under review. Present Academy of Pediatric Dentistry recommendations are presented below. 3.

29. TEXT FLUORIDE SUPPLEMENTS F F in drinking water Academy of Pediatric Dentistry current recommendations

30. Determine F intake • Determine caries risk • Devise personalized plan based on risk level. • Stress bioavailability of F. • Monitor F intake of young patients in an effort to prevent fluorosis. SUMMARY OF PREVENTIVE F

31. TEXT Arrest of Active Decay Mechanisms: Caries arrest means that active lesions become inactive. This is accomplished clinically by adjusting several aspects of the oral environment such as by reducing intake of cariogenic dietary substrates, reducing plaque volume, stimulating salivary flow, increasing plaque levels of Ca++ and PO4---, promoting favorable microbial shifts (i.e. reducing acidogenic and aciduric bacteria and encouraging proliferation of alkalinogenic bacteria) and increasing bioavailable F. Bioavailable F arrests caries by 1) inhibiting decalcification by coating enamel crystals, intact or partially decalcified, with loosely bound F and thereby preventing further dissolution of crystals, 2) catalyzing reprecipitation of dissolved enamel crystals and 3) inhibiting acidogenesis and aciduricity of cariogenic bacteria. Arrested incipient lesions appear either as dark stained fissures which resist explorer penetration (Active probing of stained fissures with sharp explorers is not recommended as it may induce cavitation.), stained cervical incipient lesions or shiny enamel surfaces covering white spot lesions. Arrested carious dentin or root surfaces exhibit dark staining with hard and often shiny surfaces. 1.

32. TEXT Arrest of Active Decay Clinical recommendations: 1) Determine total F exposure, 2) determine caries risk and tailor clinical measures to risk status, 3) institute dietary and plaque control procedures, 4) control cariogenic bacteria, if indicated and 5) have patient maintain continual low level F exposure to decalcified sites. 2.

33. ARREST OF ACTIVE DECAY Root caries Indications: incipiencies Cases difficult to treat, i.e., certain ECC cases Interproximal caries in low or moderate risk patients.

34. ARREST OF ACTIVE DECAY Ca PO4 PO4 3. Ca Procedure: Diet control Increase topical Ca and PO4 intake. 1. 4. LB MS 2. Encourage beneficial microbial shifts. Plaque control

35. ARREST OF ACTIVE DECAY 5. Increase bioavailable F F S F SUGAR P F ACID F T Arrested caries turns dark, is firm and often glossy.

36. TEXT Remineralization of Decalcified Surfaces Indications and mechanisms: This clinical manipulation is intended to restore lost mineral from incipient lesions and reverse appearance of white spot lesions. (Review notes on remineralization from Cariology course.) Generally, remineralization procedures are indicated for non-cavitated carious dental surfaces (enamel or cemental) in individuals who are not in the high or severe caries risk category. These are the same as caries arrest procedures with the exceptions that 1) only non-cavitated lesions are indicated and 2) F, Ca++ and PO4--- exposure are monitored more carefully. Recommendations: Follow recommendations for caries arrest, above, along with application of recalcifying solutions (e.g., Enamelon, which contains F) and/or F to affected sites. Recalcification of white spot lesions on anterior smooth surfaces require low concentrations of topical F (100 to 250ppm) since higher ones do not penetrate enamel as effectively and may cause preservation of the white spot by reacting only with the outer enamel layer. 1. 2.

37. REMINERALIZATION • Same procedures as for arresting caries. • Exceptions or additions: • Only non-cavitated • lesions can be • remineralized. • Not recommended for • severe of high caries risk • patients. • Ca, PO4 and F are • administered more • precisely. White spot before after

38. TEXT Clinical Fluoride Products These include 1) professional topical F, 2) F varnishes 3) home rinses and gels, 4) dentifrices, 5) supplements and 6) other agents such as sustained release devices. A detailed summary is presented in Tables at the end of the presentation. Professional Topical F Products and description: The principal products are 2.72% acidulated phosphate fluoride(APF) gel and 2% neutral sodium fluoride gel. Stannous fluoride (SnF2) is no longer used routinely for professional topical applications. APF, pH 3.5, contains 12,300 ppm F and is formulated from sodium fluoride and 0.1M phosphoric acid. This gel is intended to dissolve surface enamel which will re-precipitate with higher FHA content. Neutral NaF gels (9200 ppm F) are indicated when composite restorations are present since APF will etch glass filler particles of the composites. This product will not produce comparable surface FHA deposition, but according to research evidence, achieves the same caries protection as APF. 1.

39. Professional Topical F TEXT Mechanisms of caries protection: The earlier theories centered on increasing deposition of FHA. Now it is believed that benefits are derived mainly from residual F buildup in plaque and other oral surfaces or biofilms in the form of CaF2, other minerals and protein-bound F. These reservoirs release F during acidification which acts as bioavailable F. (Note: sealants should not be placed immediately after professional topical F treatment due to instability of the CaF2 layer which precipitates on the tooth surface. Sealants may be placed after 24 hours.) When applied every 6 months to children in F deficient regions, all types of professional topical F agents achieved roughly 30% caries reduction versus sham treated controls. 2.

40. PROFESSIONAL TOPICAL F Topical Fluorides: APF Reprecipitation of fluorapatite 2.72% acidulated phosphate F (APF), 1.23% free F, 12,300 ppm F. 2.0% neutral sodium F, 0.9% free F, 9200 ppm F. 8% stannous F (no longer used routinely). 2. F Ca PO4 F 1. 0.1 M H3OP4 3. Ca H+ Ca H+ PO4 Ca Precipitation of calcium fluoride on enamel surface Dissolution of surface layer

41. PROFESSIONAL TOPICAL F CaF2 Do not seal teeth immediately after a topical F treatment due to CaF2. H+ H+ H+ Etched glass Ca F T F Ca APF will etch glass in filled resins. Use neutral F gel. Plaque acids will release bioavailable F from CaF2. resin

42. TEXT Professional Topical F Recommendations: 1) Determine total F exposure. 2) Determine caries risk. 3) Administer as indicated by # 1 and 2. (Timing may be monthly, 1, 2, 3 or 4 times a year or even contra-indicated.) 4) Apply for 4 minutes. 5) Add no more than 2ml to the gel tray and make every effort to keep patient from swallowing the gel. 6) Have patient refrain from rinsing, eating or drinking for 30 minutes after application. 3.

43. PROFESSIONAL TOPICAL F • Recommendations: • Determine total F exposure. • Administer 0,1,2,3,4 times a year as indicated by caries risk level. • Apply for 4 minutes. • Use only 2 ml of gel in trays, keep patients from swallowing the gel. • No rinsing, drinking or eating for 30 min. afterwards. caries placebo topical Two topical F treatments per year reduced caries by 30% versus placebo gel.

44. TEXT Fluoride Varnish Products and use: Application of F varnish is essentially a professional topical F treatment. Duraflor is currently the only concentrated F varnish sold in the US (called Duraphat in Europe) and contains 5% NaF. Flor-Protector contains 0.7% silane F and is used as a cavity varnish. For topical treatments Duraflor should be applied to, and allowed to dry on all cotton roll-isolated teeth. Afterwards the patient should not eat for 2 hours. Although the caries benefits are similar to topical F gels, less total F is released into the oral cavity during treatment (i.e., only 3 to 6mg ) than from gels. Indications: Apply to: 1) teeth during operating room procedures, 2) enamel incipiencies, 3) exposed roots, 4) margins of restorations, 5) teeth at risk which cannot be sealed such as erupting molars or premolars or 6) carious anterior teeth in very young children. 1. 2.

45. FLUORIDE VARNISH Duraflor – 5% NaF, 26,000 ppm F, 3-6 mg F per dose. Fluor-Protector – 0.7% silane F. Used as a cavity varnish

46. FLUORIDE VARNISH 0.25 ml for primary dentition 0.40 ml for mixed dentition Cavity Shield (OMNI) – 5% NaF

47. FLUORIDE VARNISH Indications: 3. Exposed roots and root caries 5. Erupting teeth 1. All teeth in the OR 2. 6. Carious anterior teeth in young children 4. White spots or other incipiencies Margins of restorations

48. TEXT Home Rinses Products and use: These are available as over-the-counter (OTC) daily rinses (0.05% NaF, 230ppm F; 0.02% NaF, 200ppm), or as prescription weekly rinses (0.2% NaF, 910ppm F or 0.4% SnF2, 970ppm F). Patients should rinse 1x/day for 1 minute with 10ml. Indications: 1) High caries risk patients. 2) Exposed root surfaces. 3) School prevention programs. 1. 2.

49. HOME F RINSES Weekly Rinse Daily Rinse: 0.2% NaF, 0.091% free F, 910 ppm F, 9.1 mg F / dose. ACT PREVI-DENT 0.05% NaF, 0.023% free F, 230 ppm F, 2.3 mg F / dose • Indications: • High caries risk • Exposed roots • Prevention programs PHOS-FLOR 0.02% APF, 0.02% free F, 200 ppm F, 2 mg F / dose.

50. TEXT Home Gels Products and use: Home gels are available as prescription 1.1% NaF (5000ppm F) and 0.4% SnF2 (1000ppm). These are self-administered by the exposure of F to teeth than do rinses. Indications: 1) High or severe (rampant) caries risk patients. 2) Exposed root surfaces when evidence of caries is present. 3) School prevention programs.