G00D MORNING

TOPICAL FLUORIDEGuided by Dr. MAHMOOD MOOTHEDATH Dr.ASEELA AHMEDSubmitted by WASSIM ABDULLA

INDEX

• Introduction• Definition• Indications• Classification• Professionally applied topical fluorides• Rationale for using topical fluoride agents• Fluoride vehicles• Topical fluoride compounds used in preventive dentistry• Method of application of topical fluorides • Professionally administered application of fluoride solutions• Mode of action• Fluoride distribution on the surface of teeth

• Limitations of professionally applied topical fluoride• Recommendations for topical application• Self applied topical fluorides• Dentifrices• Fluoride mouth rinses• Fluoride gels • Factors affecting topical fluoride deposition in teeth• Benefits of topical fluoride• Risk of topical fluoride• Toxicity of fluorides• Emergency treatment for fluoride overdose• Conclusion • References

INTRODUCTION

Dental caries is a major dental disease affecting a large proportion of the inhabitants of the world. It impairs the quality of life for many people causing pain and discomfort. The cariostatic efficacy has been convincingly demonstrated and the recent decline in caries prevalence is primarily attributed to the increased use of fluoride agents.

DEFINITIONBy definition the term “TOPICALLY APPLIED FLUORIDES” is used to describe those delivery systems which provide fluoride for a chemical reaction to exposed surfaces of the erupted dentition.

INDICATIONS

1. Caries active individuals2. Children shortly after periods of tooth eruption3. Those who take medication that decrease salivary flow or have

received radiation to head & neck4. After periodontal surgery5. Patients with RPD or FPD and after placement or replacement of

restorations6. Patients with an eating disorder7. Mentally & physically challenged individuals

Fluorides

Topical fluorides

Professionally

appliedSelf

applied

Systemic fluorides

CLASSIFICATION

a) Community water fluoridation

b)Salt fluoridation

c)School water fluoridation

d)Milk fluoridation

e)Fluoride supplements

SYSTEMIC FLUORIDES

TOPICAL FLUORIDESA)Professionally applied i. Sodium fluoride preparationii. Stannous fluoride preparationiii. Acidulated phosphate fluorideiv. Fluoride varnishv. Fluoride impregnated floss & prophylactic pastevi. Fluoride containing dental materials

B)Self appliedvii. Fluoridated dentifriceviii. Fluoride mouth rinsesix. Fluoride gels

PROFESSIONALLY APPLIED TOPICAL FLUORIDES Topical fluoride application by a dentist, hygienist or other dental auxillary has become an established caries preventive procedure in the dental officeMedicaments typically dispensed usually involve the use of high fluoride concentration products, ranging from 5000 &19,000 ppm, which is equivalent to 5-19 mgF/ml→ Three agents currently in use are,1) Neutral sodium fluoride(NaF)2) Acidulated phosphate fluoride(APF)3) Stannous fluoride(SnF2)

RATIONALE FOR USING TOPICAL FLUORIDE AGENTS To speed the rate & increase the concentration of

fluoride acquisition above the level, which occurs naturally

Since immature & porous enamel acquires fluoride rapidly and teeth undergoes rapid maturation ,it follows that best time to apply topical fluoride is soon after eruption

Pre treating enamel with 0.05M phosphoric acid ,in order to increase enamel surface area , greatly enhances the uptake and retention of fluoride

Lengthening the time interval between the applications of a solution also increases fluoride uptake

FLUORIDE VEHICLES 1)Aqueous solutions & gels 2 )Fluoridated prophylactic paste 3)Foam 4)Fluoride varnish AQUEOUS SOLUTIONS & GELS• Gel adheres to teeth for considerable amount of time & eliminates

the continuous wetting of enamel surfaces• Since each application may be loaded by coating it with a thin layer of

gel , hazard of accidentally ingesting a large quantity of fluoride is minimized

• Application of aqueous fluoride using the step prophylaxis & topical fluoride method is a time consuming procedure

FLUORIDATED PROPHYLACTIC PASTES• Surface enamel contains higher levels of fluoride than the internal

layers which removes under a prophylaxis• Fluoridated prophylactic paste replenish the lost fluoride & there is

a small , but significant net gain in the concentration of fluoride

FOAM• To minimize the risk of fluoride over dosage as well as to maintain

the efficacy of topical fluoride treatment• The advantage of foam based APF agents are,i. Only small amount of the agent is neededii. Material can penetrate in to the proximal surfacesiii. Does not require suctioning

FLUORIDE VARNISH

• Increasing the time of contact between the enamel surface & favors the deposition of more permanently bound fluorapatite & fluorhydroxyapatite

• DURAPHATE, 1st fluoride varnish ,contain 22,600 ppm fluoride , shown caries reduction of 30%-40% in permanent dentition & 7% - 44% in primary dentition

• FLUORPROTECTOR , contain 7000 ppm fluoride has an efficacy of 1% - 17%

• CAREX contains a lower fluoride concentration than Duraphate & has an efficacy equivalent to that of Duraphate

FLUORIDE VARNISH APPLICATION

METHODS OF APPLICATION OF TOPICAL FLUORIDE

1) Paint on technique• Teeth are cleaned , dried & isolated Saliva absorbers may also be used• The solution is continuously applied keeping the teeth

isolated for 4 mints• During this 4 mints unwaxed dental floss which have been

soaked in the solution is passed interproximally

2)Tray technique• Fluoride gels can be applied in trays eg : APF

TOPICAL FLUORIDE COMPOUNDS USED IN PREVENTIVE DENTISTRY1)NEUTRAL SODIUM FLUORIDE• First fluoride compound to be used• A minimum of four application with a 2% NaF solution gives a

caries reduction of about 30%Method of preparation20gms NaF powder + 1 ltr distilled water(plastic container)Method of application(Knutson’s technique) 4 appointments The teeth are cleaned , dried & isolated The solution is painted using cotton tipped applicator sticks&

allowed to dry for 3 to 4 minutes

The procedure is repeated for each of the isolated segments

The 2nd , 3rd & 4th are scheduled at intervals of 1 week Recommended for ages 3 , 7 , 11 & 13 years.

Mechanism of action Reacts with hydroxyapatite crystals to form

calcium fluoride As a thick layer of CaF2 gets formed , there is a

sudden stop of entry of fluoride , which is termed as “chocking off effect”

CaF2 reacts with hydroxyapatite crystals to form fluoridated hydroxy apatite

Advantages• No need to prepare a fresh solution for each patient• Acceptable taste• Non irritating to gingiva• Does not cause discoloration• Since solution is allowed to dry for 3 minutes , the clinician in

public health programs can persue a multiple chair procedure• The series of treatments must be repeated only four times in

general age range of 3 to13, rather than at annual or semiannual intervals

DisadvantagesPatient must visit 4 times to dentist within a relatively short period of time

Technique of application(Muhler’s technique)• Teeth are cleaned , dried & isolated• Solution is applied using the paint on technique and kept for 4

minutesRepeat applications are made after 6 months

STANNOUS FLUORIDE(SnF2)

Most commonly used is 8% SnF2 solutionMethod of preparation1 capsule 0.8 gms +10 ml distilled water (plastic container)

Mechanism of action At low concentration , tin hydroxy phosphate is formed At very high concentrations , calcium tri fluoro stannate gets

formed along with tin trifluoro phosphate , which is responsible for making the tooth structure more stable & less susceptible to decay.

CaF2 is also the end product both at low & high concentrations , which further reacts with hydroxy apatite & small fraction of fluoro hydroxyapatite also gets formed

Advantageso Using at 6 to 12 months intervals conforms to the

practicing dentist ‘s usual patient recall systemo Administrative difficulties , particularly in public health

programs created by the need to arrange 4 appointments are avoided

Disadvantageso In aqueous solution the material is not stableo Disagreeable in tasteo Cause irritation to gingivao Cause pigmentation of teeth

ACIDULATED PHOSPHATE FLUORIDE(APF) Brudevold’s solutionMethod of preparation 20 gms NaF + 1 ltr 0.1 M phosphoric acid .To this is added

50% hydrofluoric acid to adjust pH at 3 & fluoride ion concentration at 1.23%

For gel preparation , a gelling agent like methylcellulose or hydroxy ethyl cellulose is added & pH is adjusted between 4-5

Technique of application Aqueous preparation – paint on technique gel preparation – tray technique Recommended for application at 6 or 12 months intervala) Patient should sit uprightb) Oral prophylaxis is done

c) Teeth are isolated & driedd) Clinical application APF gel using trayse) After the trays have been positioned , saliva ejector is

usedf) It is reapplied every 15- 30 seconds throughout the 4

mints periodg) The patient should be told to exert slight pressure using

the tongue & cheeks. The fluoride gel should be in the mouth for 4 mints and then the remaining oral fluid should be expectorated

h) Patient is instructed not to eat, drink or rinse for at least 30 mints

Mechanism of action→ When APF is applied on the teeth , it initially leads to

dehydration & shrinkage in the volume of hydroxy apatite crystals which further on hydrolysis forms an intermediate product called di calcium phosphate di hydrate( DCPD)

→ DCPD is highly reactive with fluoride ion→ Fluoride penetrates into the crystals more deeply

through the openings produced by shrinkage & leads to formation of fluorapatite

Advantages1. Requires only 2 applications in a year2. The gel preparation can be self applied & thus the cost

of application also gets reduced3. Has the ability to deposit fluoride in enamel to a

deeper depth4. It is stable & need not be freshly prepared for each

patientDisadvantages5. It is acidic , sour & bitter taste6. It needs more chair side time7. It cannot be stored in glass containers

PROFESSIONALLY ADMINISTERED APPLICATIONS OF FLUORIDE SOLUTIONS1) The Knutson’s technique2) Muhler’s single application technique3) The Mercer and Muhler technique4) The Dubbing and Muhler technique5) Szwejda – Knutson multiple chair technique6) The Englader technique

METHODS OF ENHANCING FLUORIDE FIXATION IN ENAMEL1) Increase in frequency of application and time exposures2) Pretreatment of enamel surface3) By acidified saturated solution of Dicalcium Phosphate Dihydrate4) Use of complexing agents

MODE OF ACTION1. Remineralization of enamel2. Alteration in the morphology3. Delayed eruption of teeth4. Inhibition of plaque bacteria5. Inhibition of plaque formation

FLUORIDE DISTRIBUTION ON THE TOOTH SURFACE

◊ In young anterior teeth , fluoride concentration on the enamel surface decreases from the incisal edge towards cervical margin

◊ In older teeth this pattern is reversed◊ From the enamel surface to the interior the

concentration of fluoride decreases◊ Porous or carious enamel readily absorbs

fluoride while sound enamel absorbs very little or at least not in a permanently bound form

LIMITATIONS OF PROFESSIONALLY APPLIED TOPICAL FLUORIDE

• Personal costs associated with one to one method of fluoride delivery

• Use of operator applied topical fluoride in public health programs has been the difficulty of implementation in areas with a shortage of dental personal

RECOMMENDATIONS FOR TOPICAL APPLICATIONNo more than 2gm of gel per tray or approximately 40% of tray capacity should be dispensed. Even more conservative amounts should be considered for small children.Because patient may have the need to swallow during a 4 minute topical application procedure, the use of a saliva ejector during the procedure is recommended.Following the 4 minute application procedure the patient should be instructed to expectorate thoroughly for 30 sec to 1 minute, regardless of whether high speed suction is utilized or not. Expectoration is probably the single most effective way of reducing orally retained fluoride.

SELF APPLIED TOPICAL FLUORIDESControl of dental caries rests largely in the personal lifestyle of the individual and that the sensible use of the fluoride at home is an important part of this behavior

Self applied topical systems include

1) Fluoride dentifrices2) Fluoride gels3) Fluoride mouth rinses

DENTIFRICESFluoride compounds in dentifrices• Sodium fluoride dentifrices• Stannous fluoride dentifrices• Mono fluoro phosphate• Amine fluoride dentifriceAdverse effects of dentifrices A single brushing with a full ribbon of paste on a brush head will

cause toxicity when children eat it. Detergents & flavoring oils irritate the stomach when ingested in

large amounts & cause vomiting Abrasives may interfere with complete intestinal absorption of

fluoride from tooth paste Produce dental fluorosis from the regular ingestion of small

amounts by children

FLUORIDE MOUTHRINSES

1)Sodium fluoride mouth rinses→ Formulated at concentrations of either 0.2% for weekly use or 0.05% for

daily usePreparationHome use;200mg NaF tablet+5 teaspoons of clean waterIn schools;Packet of NaF powder+100 ml water2)Other mouth rinses• Stannous fluoride rinses• Amine fluoride rinses• Ammonium fluoride rinsesMechanism of action Fluoride changes the enamel structure of teeth from predominantly

hydroxy apatite to fluorapatite Fluoride may act by inhibition of bacterial metabolism & plaque acid

formation

FLUORIDE GELS• Gels are either applied in trays or

brushed on the teeth• Professionally applied - twice a year self applied – once a day or more• Patients brush their teeth for 1 mint

with the gel or if trays are used several drops are placed in each tray and held in contact with the teeth for 5 mints. Patient should be cautioned to expectorate excess gel and not to swallow it. Also patient should rinse with tap water after brushing or tray application

FACTORS AFFECTING TOPICAL FLUORIDE DEPOSITION IN TEETH1)Tooth conditioni. Tooth ageii. Natural fluoride concentrationiii. Enamel defectsiv. Dentine/cementum

2)Treatment formulationv. Fluoride agentsvi. pHvii. Fluoride concentrationviii.Formulation componentsix. Abrasives

3)Application proceduresi. Prophylaxisii. Effect of timeiii. Temperatureiv. Number of applicationsv. Sequential APF – SnF2 applicationvi. Enamel pre treatmentvii. Barrier coating

BENEFITS OF TOPICAL FLUORIDEPrevention of dental cariesPromote gingival health by selectively affecting ‘strepto coccus mutans’Bone metabolism in both healthy & diseased individualsImportant in the arrest & reversal of incipient lesions Economic & psychosocial benefits

RISK OF TOPICAL FLUORIDERelatively few physical problems such as→ Gastro intestinal disturbances →Staining of the teeth→Gingival mucosal irritation→Dental fluorosisOnly serious one is dental fluorosis , because it is the only condition that is permanent & also that has the potential of causing psychosocial problems

TOXICITY OF FLUORIDE1) Acute toxicity• Results from rapid excessive ingestion of fluoride at one time• Most frequently encountered adverse effect of topical

fluoride therapy is nausea• Other symptoms of fluoride toxicity include abdominal

cramps , vomiting , diarrhea , increased salivation , dehydration & thirst

• Causes death by blocking normal cellular metabolism• Certainly Lethal Dose(CLD) 32 – 64 mg of fluoride/kg

body wt• Safety Tolerated Dose(STD) 8 – 16 mg of fluoride/kg

body wt

2)Chronic toxicity Results from long term ingestion of small amounts of fluorideA)Dental Fluorosis•Caused by excessive intake of fluoride during tooth development•Ingestion of water with a fluoride concentration 2 or 3 times greater than recommended amount causes white flecks & chalky opaque areas on the tooth enamel•Consumption of water containing 4 times the recommended amount of fluoride causes a brown pitted corroded appearance on the enamel surface

ii. Skeletal fluorosis• Caused from ingestion of very high amounts of fluorides

for long periods of time• Severe pain in the back bones , joints , hips , stiffness in

joints & spine• Outward bending of legs & hands is seen in advanced

stages and these parts loose their shape & contours. This is called Knock-Knee syndrome

• Pregnant & lactating mothers and children are the most vulnerable group.

• Fluoride may lead to blocking & calcification of blood vessels

• In its severe form , “crippling fluorosis” the spine becomes rigid & the joints stiffen virtually immobilizing the patient

EMERGENCY TREATMENT FOR FLUORIDE OVER DOSE

Milligram fluoride ion per kilogram body weight

Treatment

Less than 5mg/kg 1)Give calcium orally2)Induced vomiting not necessary

More than 5mg/kg 1)Empty stomach by inducing vomiting with emetic2)Give calcium orally3)Admit to hospital & observe for a few hours

More than 15mg/kg 1)Admit to hospital immediately2)Induce vomiting3)Begin cardiac monitoring 4)Slowly administer 10 ml of 10% calcium gluoconate iv5)Adequate urine output should be maintained using diuretics if necessary6)General supportive measures

• When used appropriately fluoride is safe and effective agent that can be used to prevent & control dental caries• Useful in management of root caries & root surface hypersensitivity in adult patients with exposed root surfaces• Useful alternative for caries in special needs such as those with developmental disabilities• Children and adolescents undergoing orthodontic treatment tent to have poor plaque control and benefit generally from varnish application

REFERENCES

•Essentials of Preventive & Community Dentistry – Soben Peter• Textbook of Preventive & Community Dentistry – S S Hiremath• Primary Preventive Dentistry – Norman O Harris