TOPICAL FLUORIDES

Indications

• Primary preventive measure : provided to all children

Focuses only on the potential benefits/ignoring costs.

• Only for those at significant risk of developing caries.

Sodium Fluoride-2%• Ph -7/9040ppm

• Preparation: 20gm NaF in 1L distilled water in plastic bottles.

• Application: Knutson’s technique

• Oral prophylaxis

• Isolate upper & opposing lower quadrant-cotton rolls

• Dry teeth

• Apply with cotton applicators

..• CHOKING OFF• 2nd/3rd/4th application at weekly intervals -

3/7/11/13yrs• ADVANTAGES: acceptable taste,• non irritating to soft or hard tissue• Cheap• No discolouration• DISADVANTAGES• 4 visits in short span• Limited effectiveness

Mechanism of action

• Ca10 (PO4)OH2 + 20F- 10CaF2 + 6PO- +2OH-

• CaF2 + Ca5(PO4)3OH 2Ca5(PO4)3F +

Ca(OH)2

Stannous fluoride

• Muhler et al ,2%, 4%, 8% -19360 ppm

• Preparation: 0 no gelatin caps filled with 0.8 gm of SnF2 / stored in air tight plastic containers

• One capsule dissolved in 10 ml of distilled water in plastic container & shaken

Muhler’s technique

• Oral prophylaxis

• Isolate

• Apply freshly prepare SnF2 continuously.

• Every 15-30 sec for 4min

• Not to eat drink/ rinse for 30 mins

• Annual application

Disadvantages• Highly unstable• Low ph 2.1-2.3• Metallic/astringent taste• Gingival tissue irritation• Brownish discoloration of partially

demineralised /hypo calcified enamel.• Grayish discoloration of restorationsAdvantages• Rapid penetration of Sn & F: amorphous

layer of SnFphosphate

Mechanism of action

• Low conc• Ca5(PO4)3 + 2SnF2 CaF2+

Sn(OH)PO4+Ca3(PO4)2

High conc• Ca5(PO4)3 + 16SnF2 CaF2+ 2Sn3F3PO4

Sn(OH)PO4 + 4CaF2(SnF3)2

• Ca5(PO4)3 + CaF2 2Ca5(PO4)3F +

Ca(OH)2

• Stannous trifluoro phosphate: main product

• Stannous hydroxyphosphate: metallic taste

• Calciumtrifluorostanate

• Calcium fluoride

APF SOLUTION• 1.23%,12,300ppm,pH-3• Brudevold & co-workers• 20gms NaF in 1L, 0.1M H3PO4. Add 50% HF

acid to adjust pH to 3 & F conc to 1.23%• Technique: Prophylaxis/isolate• APF applied repeatedly quadrant wise• Keep tooth moist for 4 mins• No eating/drinking/rinsing for 30 mins• Semiannual application

• ADVANTAGES

• Deposits F to a greater depth

• DISADVANTAGES

• Kept wet for 4 mins

• Acidic/sour & bitter

• MOA: Low pH produces dissolution & formation of CaF2.

• FAP formed as retained CaF2 is dissolved away from surface

Mechanism of action

• Ca5(PO4)3 + 4H+ ---> Ca2+ +3HPO4- + H2O

• Ca2+ +HPO4- ---> Ca.HPO4.2H2O

(dehydration & shrinkage)

• 5Ca.HPO.2H2O + F- ---> Ca5(PO4)3F + 3H+

+ 2HPO4- + 2H2O

APF GEL

• 1.23%,12,300ppm, pH : 4-5

• Methylcellulose/hydroxyethyl cellulose

• Application : prophylaxis & dry

• Fill U/L trays with APF GEL

• insert simultaneously & bite down for 4 mins

• Instructions

ADVANTAGES

• Flavoured taste

• Easy application

• Thixotropic property

Caries reduction > APF SOLUTION

DISADVANTAGES

• Irritation to inflamed gingival tissue & open carious lesions

Fluoride Varnish

• Germany in 1964 as Duraphat (5%NaF)

• Prolong contact of F with tooth surface

• Duraphat/ Duraflor/ Flour Protector(1 % difluorosilane)

• 1994 Duraphat cleared by FDA: CAVITY LINERS & HYPERSENSITIVE TEETH

• Use as caries preventive measure is “ off label”

• Duraphat/duraflor: 2.26% F

• Fluo Protector: 0.1% F

• Carex :1.8%F

• Bifluoride: NaF & CaF2

• Cavity shield

• Flouritop

APPLICATION• Brushing /dry with gauze/cotton• Cotton tip applicator/syringe type applicator 0.3-0.5 ml F• Application time 1-4 mins• Varnish sets in contact with moisture• Not to eat for 2-4hrs/ avoid brushing that

night• Semiannual • 25 yrs of clinical trials:25-45% caries

reduction

Mechanism of action

• 10Ca5 (PO4)3OH + 10F- 2CaF2 + 6Ca5(PO4)3F+ 6 Ca3(PO4)2 + 10 OH

• 2Ca5 (PO4)3OH + CaF2 2Ca5(PO4)3F + Ca(OH)2

Fluoride Foams

• Less dense than gel:better flow.

• Total density by wt less than gel: risk of systemic toxicity is less.

• Ph of 6

• Marketed only in some countries

• Retention on tooth is less

F tooth pastes• Abrasive/Si/15-25%• Humectant/glycerine+ sorbitol/45-50%• Water/1-5%• Detergent/sodium lauryl sulphate/1-2%• Buffer/sodium citrate/1-5%• Binder/xanthum gum/0.5-2%• Flavouring agent/menthol/lemon oil etc/1-4%• Sweetner/saccharin• Opacifier/TiO2 + coloring agent/

• Therapeutic agent: NaF/NaMFPO4

• Stabilizer: sodium benzoate

• Early dentifrices: CaHPO4/ CaCO3/Na metaphosphate

• NaF + Calcium abrasives = CaF2

• Stannous fluoride dentifrices• 1st ADA accepted SnF2 + Ca2P2O7 ( CREST)• AIM

• Disadvantages

• Light greyish staining of teeth

• SnF2 unstable in nature

• Manufacture: difficult & expensive

• NaMFP

• 0.76% NaMFP by colgate in 1963

• Compatible with large no of abrasives

• MFP + NaF : superior to MFP

• MFP + DCPD

NaF dentifrices

• Early systems were ineffective

• Polyacrylic particles/SiO2/Ca pyrophosphate.

• New Crest : Neutral NaF & hydrated silica.

• CDT in 1983

• More effective than older crest

Amine fluoride dentifrices

• Elmex ( Switzerland)

• Amine F with sodium metaphosphate

• Sparse clinical data

• Unpleasant taste

• Toxicity ?

• Not in America

RECOMMENDATIONS• 6 Months: 450-600 ppm

• 1000-1500 ppm tooth pastes to be avoided till 4 years

• 4-6 yrs : once with F tooth paste

• 6 – 12 yrs : twice

• >12 yrs :thrice

• Preschool : supervised

• Pea sized amount below 6 yrs

FLUORIDE RINSES• Bibby et al,1946: acidified NaF• Initial clinical trials: Sweden (Torell &

Siberg,1962) & USA ( Weisz,1960).• Neutral NaF : SIGNIFICANT CARIES

REDUCTION• Optimal conc & frequency????• Long term use in school trials = communal

water fluoridation BUT AT GREATER COST• Young children small but significant amount

ingested : systemic effect

RATIONALE• High levels of F in plaque

• Inhibit glycolysis

• Repeated exposure : remineralization

• Effective in animal trials

• SnF additional cariostatic mechanisms:

Antibacteial effect +inhibit plaque accumulation by reducing surface energy of enamel

• Neutral/ acidfied• Aqueous/ alcohol• 0.2% weekly (900ppm)• 0.05% daily (225ppm)• Forceful swishing of 10 ml for 60sec• Not to be swallowed: preschool

children omitted

NaF Rinses

Indications• High caries susceptibility• Ortho/prostho appliances• Medical/physical disabilities

Advantages• Simple• Well accepted /Safe• Inexpensive• $ 0.75/student: annual cost of weekly NaF

rinse

OTHER RINSES

• 0.044% APF : DAILY

• 0.01% SnF2 : DAILY

• MILD STAINING

• ASTRINGENT TASTE

• F impregnated floss• Gillings in 1973• Naf/SnF2

• Decrease & S. mutans count• No clinical trials evidence of decreased

caries/ gingivitis.

• F chewing gums• F + XYLITOL• salivary stimulator

• A high F concentration in saliva and a significant F uptake in enamel

F Alginates• Zelgan & Kerr

• F in saliva :111PPM

• Limited clinical value : limited anticaries activity for short duration

Intra oral Controlled release Fluoride Devices

• F containing copolymer matrix encapsulated by copolymer membrane

• F released at predetermined rate over a period of time

• Can elevate salivary F conc from 0.022 to 0.2/0.3ppm for 100 days

• Mean plaque levels can be raised to 35ppm

• Expensive/ limited clinical trials

F containing restorative materials

• Amalgam

• Enamel surface : decreased acid solubility

• decreased corrosion resistance & compressive strength

• GIC

• NaF/SnF2 incorporated into ZOE

• Carboxylate cement

• F + CHX preparations• Decreased S mutans count

• Gel/ dentifrice

• Iontophoresis• Electric current to drive F deeper into

enamel

• Treatment of hypersensitivity: placebo effect