topical fluorides
TRANSCRIPT
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