Professionally applied topical fluorides

Dr. Shivashankar.K1st year M.D.S. Department of P.H.D.Saveetha Dental College.

Contents Introduction Definition Indications Contraindications Rationale Technique of application Products Sodium fluoride Stannous fluoride Acidulated Phosphate fluoride Fluoride varnish In-office mouth rinse Conclusion

Introduction

Definition Topical fluoride therapy refers to the use of systems containing

relatively large, concentrations of fluoride that are applied

locally, or topically, to erupted tooth surfaces to prevent the

formation of dental caries.Richard. E. Stallard- A Textbook of Preventive Dentistry. 2nd edition.

Indications Patients who are at high risk for caries on smooth tooth

surfaces

Patients who are at high risk for caries on root surfaces

Special patient groups, such as: Orthodontic patients

Patients undergoing head and neck irradiation

Patients with decreased salivary flow

Children whose permanent molars should, but cannot, be

sealed

Contraindications

Patients with low caries risk who reside in communities with optimal fluoridation

Rationale for topical fluoride

Fluoride concentration of enamel is inversely related to the prevalence of dental caries (1940- Volker and Colleagues ).

Keen et al in 1973 showed the relationship between surface enamel fluoride content and caries prevalence.

Highest concentration of fluoride occurs at the outermost portion of the enamel surface(5 to 10 micron), and decreases towards the dentin (Brudevold et al 1975)

Technique of topical application

1. Paint on technique2. Tray technique

Products

Neutral sodium fluoride solution (NaF)

Stannous fluoride (SnF2)

Acidulated phosphate agents

Varnish

In office fluoride mouth rinses.

Sodium fluoride (2%)Preparation:

20 gms NaF dissolved in 1lt of distilled water

Plastic bottle

Knutson’s technique Cleaning and polishing

Isolated with cotton roll

Teeth dried

Paint on with applicator tip

Dry for 4 min

Avoid eating, drinking or rinsing for 30 min

Weekly intervals

Recommended ages 3,7,11 &13 years, 4 times weekly intervals

Mechanism of action Sodium fluoride reacts with hydroxyapatite crystals forming

CaF2

Fluoride concentration – 9000 ppm

Chocking off- initial rapid reaction followed by reduction in its

rate.

Thick layer of calcium fluoride interferes with further diffusion

Calcium fluoride reacts with hydroxyapatite forming fluoridated

hydroxyapatite.

Less susceptible to caries, stable product.

Plaque metabolism- anti- enzymatic action.

Advantages and disadvantages

ADVANTAGES:

1) Relatively stable, Needs Plastic Containers

2) Well acceptable taste, Non Irritating and no -discoloration

3) Suited for public health programmes

DISADVANTAGES:

4 visits relatively at short period of time .

1940- volker et al invitro study- solublity of enamel is reduced.

1941- Bibby had done 1st clinical study using a 0.1% aqueous NaF solution for 7-8 min. 1 year follow-up. 45% caries increment.

1942 - Knutson suggested technique which required 4 visits. 1948- Knutson and galagan 1% aqueous NaF. 4.9-5.8%

reduction. 1959- Sundvall- Hagland et al studied the effectiveness

of Knutson technique on caries incidence in the deciduous teeth. .5% reduction in caries increment.

STANNOUS FLUORIDE(STANNOUS FLUORIDE 8%)

PREPARATION………0.8gms in 10ml water

METHOD OF APPLICATION:

Cleaning and polishing

Isolated with cotton roll

Teeth dried

Paint on with applicator tip

Teeth kept moist for 4 minutes

Re-application done for every 15-30 seconds.

Mechanism of action Tin reacts with enamel forming stannous tri-fluorophosphate

which is more resistant.

If exposed to air stannous form of tin gets oxidized to stannic

form.

Main end-products:

Stannous hydroxy phosphate

Stannous- tri- fluorophosphate

Calcium tri fluorostannate

Calcium fluoride

Advantages and disadvantagesADVANTAGES:

Applications required only once per year

DISADVANTAGES:• Bitter metallic taste, disagreeable taste• Needs to be freshly prepared for each appointment• Not stable in solution • May cause reversible tissue irritation and staining at the

margins of restoration

1957- Muhler et al one application of SnF2 vs 4 application of

SnF2. 21% reduction in caries increment.

1957-1962 Muhler et al compared 1 application of SnF2 vs

4applications of NaF. 37% less caries increment which is 56%

lower than national average.

1974- Howink et al study among24 pairs of monozygotic twins.

Intervention was given to one group (1% fluoride) and other

group was control (no treatment). The intervention group

showed 37% fewer lesions compared to control group.

1960- Scott et al. Stannous fluoride forms a coating over

enamel. In-vitro electron microscope study.

1967- Stannous ions may reduce fluoride uptake.

Acidulated phosphate agentsMethod of preparation : 20gms..1litre of (0.1M phosphoric acid)

added 50% hydrofluoric acid

pH adjusted to 3 & F Conc. At 1.23%

Recommended Frequency

Twice a year

Application Cleaning and polishing

Isolated with cotton roll

Teeth dried

Paint on with applicator tip

Teeth kept moist for 4 minutes

Apply for every 30 seconds

1947- Bibby et al low pH high fluoride absorption.

1963- Brudevold Fluoride concentration in enamel increases

with decrease in pH

1961- Brudevoldt et al 66% reduction in caries lesion in

children. Bitewing radiograph.

1963- Brudevold et al . Neutral sodium fluoride vs acidulated

phosphate fluoride. Split mouth trial. APF is 50% more

effective than neutral sodium fluoride.

1968- Brudevold et al, Cartwright et al. bianual APF vs tap

water. 44-49% reduction in the new DMF

OTHER METHODS Wax or plastic trays- blotting paper soaked with APF solution

Gelling agent- methylcellulose or hydroxyethyl cellulose

added and pH adjusted to 4-5.

Trays- not sure of covering proximal surfaces

Gel- thixotrophic.

APF gel

Mouth trays should be tried in the patient's mouth

Upright and suction

Teeth should be air-dried, cleaning or prophylaxis

2–2.5 grams per tray or 40% of the tray's volume.

Upper and lower trays should be inserted separately.

Fluoride should be applied for 4 minutes, not 1 minute.

Expectorate for 1–2 minutes after tray removal.

Patient should not rinse, eat, or drink for at least 30 minutes after the

procedure.

1 minute gel applicationSilverstone

majority of fluoride uptake takes place in first 1 minute after application.

Reduces gel ingestion.

Prevent etching of porcelain or composite restoration

Dental Health Education by Christilina.B.DeBiase.

1967- Szwejda et al (1st gel study) no reduction after 1 year

1968- Brayan et al 45% reduction in DMF after single

application.

1970- Ingraham et al. APF gel vs APF solution. Gel is 50%

more effective than solution. Limitations: non-homogenous

groups.

1971- Horowitz and Doyle. APF solution is better than gel.

1100 children of age group 10-12 years

A study on APF by Horowitz and Doyle (1971) The result after 3 years.

1967- Averill et al. 2 years study among 483 children of 7-11

years.

control group- saline- 4.4

2% aqueous NaF- 3.9

4%Stannous Fluoride- 4.1

2% APF- 4.5

IN-OFFICE FLUORIDE MOUTH RINSES

Two-part fluoride rinses are being used more frequently

These rinses consist of two fluorides, APF and stannous

fluoride, which are mixed or used concurrently

Two-part rinses are marketed as a preventive agent that is

better tolerated than tray applications and reduces fluoride

ingestion.

Fluoride concentrations are much lower compared with APF

gel (1,500–3,000 ppm vs. 12,300 ppm).

Second, the risk of ingestion is greater because rinses can

be more easily swallowed.

FLUORIDE VARNISH The most common types of NaF varnish are Duraphat (2.2%

F) and Fluor Protector (0.1% F).

The advantage of varnish is its ability to adhere to tooth

surfaces, which prolongs contact time between fluoride and

enamel and improves fluoride uptake into the surface layers

of enamel.

Fluoride varnishDuraphat:

22600 ppm NaF

Caries reduction 30-40 % in permanent dentition

7-44% in primary dentition

Methods

No isolation as varnish sticks to cotton

0.5 ml equivalent to 11.3mgF, enough to cover full dentition

4 mins

Fluoride varnishFluorprotector: Clear polyurethane based products Contains silane fluoride 7000ppm 40% caries reduction The recommended dose of 0.5ml contains 3.1mg FMechanism of action

Fluoride + hydroxyapaptite =fluorapatite

Remove excess moisture from teeth with a cotton swab, cotton roll, or

air syringe.

0.5–1 ml of varnish

thin layer using a disposable brush, or cotton pellet.

The entire tooth surface must be treated

Avoid applying varnish to gingival tissues because of the risk of

contact allergies.

No drying is required after application

mouth can be closed immediately following treatment.

Patients can only have fluids or soft foods during the next four hours.

Patients should not brush their teeth for the rest of the day.

Note: Varnish is contraindicated for persons with a history of allergies or

asthma

1987- Shobha, Nandlal et al, A clinical study showed fluoride varnish

was more effective than APF

1995-Seppa and Co-worker reported the semiannual application of

NaF varnish and APF gel and observed no significant difference

between the two.

1982- Seppa et al, Duraphat(66% )found to be more effective than

Fluorprotector (49%).

Conclusion

References R. Hawkins, D. Locker and J. Noble; series editor E. J. Kay

prevention. Part 7: professionally applied topical fluorides for

caries prevention. British dental journal volume 195 no. 6

SEPTEMBER 27 2003 p 313-317

Ole fejerskov, brion A.Burt fluoride in dentistry, 2nd edition,.

J.J.Murray, et al. Fluorides in caries prevention (3rd edition ),

varghese publishing house.

Thank you