Fluorides Question And Answers

Fluorides Important Notes

1. APFgel

• APF solution/ Brudevold’s solution is prepared by dissolving 20 gms of NaF in 1 liter of 0.1 M phosphoric acid and to this 50% hydrofluoric acid is added to adjust pH 3 and fluoride ion concentration at 1.23%
• APF gel is prepared by adding gelling agents like methylcellulose and hydroxyl ethyl cellulose and pH is adjusted between 4-5

2. Sodium fluoride

• It is chemically stable
• Has pleasant taste
• No irritation to the tissues
• Cheap
• The method of application is known as the Knutson technique
  • Knutson and Feldman recommended this technique
  • In this 4 applications of 2% NaF at weekly intervals in a year 3,7,11 and 13 years is done

3. Stannous fluoride

• It is an unstable solution due to the formation of Sn(OH)₂
• So it requires fresh solutions to be prepared for each patient

4. Nalgonda technique of defluoridation

• It was developed by National Environmental Engineering Research Institute at Nagpur in 1961.
• Involves the addition of aluminate or lime, bleaching powder, and filter alum to fluoride water

5. Fluoride varnishes

• Commonly used are
  • Duraphat – fluoride concentration is 22600 ppm
  • Fluor protector – fluoride concentration is 7000 ppm

6. Fluoride toxicity

Fluorides Long Essays

Question 1. What is topical fluoride? Explain about APF gel and Sodium fluoride.
Answer:

Topical Fluoride:

• It refers to the use of systems containing relatively large, concentrations of fluoride that are applied locally, or topi¬cally, to erupted tooth surfaces to prevent the formation of dental caries

Sodium Fluoride- 2%:

• Preparation: It is prepared by dissolving 20 gms. of Sodium fluoride powder in 1 liter of distilled water.

Sodium Fluoride Application (Knutson Technique):

• Clean and polish the teeth
• Isolate both the arches
• Dry the teeth thoroughly
• Apply 2% NaF with cotton applicators
• Maintain it for 4 minutes
• Repeat it for the remaining quadrant
• Avoid eating, drinking/rinsing for 30 minutes
• Repeat applications at weekly intervals
• Recommended ages – 3,7,11,13

Sodium Fluopide Mechanism Of Action:

Apf (Acidulated Phosphate Fluoride) – 1.23%:

Method Of Preparation (Brudevold’s Solution):

• It is prepared by dissolving 20 gms. of sodium fluoride in 1 liter of 0.1M phosphoric acid
• Followed by the addition of 50% hydrofluoric acid
• A gelling agent methylcellulose or hydroxyethyl cellulose is added to the solution

Brudevold’s Solution Application:

• Oral prophylaxis
• Isolate the teeth
• Dry the teeth
• Apply APF solution by loading in a tray
• Maintain it for 4 minutes

Brudevold’s Solution Frequency: – Twice in a year

Brudevold’s Solution Mechanism Of Action:

Question 2. Write in detail about the mechanism of action of fluoride in preventing dental caries. Add a note on topical fluorides for home use.
Answer:

Mechanism Of Action Of Fluoride

1. Fluoride incorporation in enamel

• Pre-eruptive incorporation:
  • Fluoride gets incorporated in the fluid-filled sac surrounding the developing tooth
  • Then it enters the developing tooth
• Post-eruptive incorporation:
  • Fluoride enters the enamel surfaces
  • Conversion of carbonated apatite and hydroxyapatite to fluorapatite and fluoro- hydroxyapatite takes place

2. Remineralization of acid

• Equilibrium exists between minerals of tooth enamel and minerals of saliva
• This is disturbed by the organic acid produced by carbohydrates
• There is a drop in pH
• Minerals leach out
• This is prevented by the remineralization by fluoride
• Fluoride penetrates into enamel rods
• It forms larger crystals that are more acid resistant

Topical Fluorides

1. Dentrifices:

• Fluoride compounds in dentifrices
  • Sodium fluoride
  • Stannous fluoride
  • Mono fluorophosphate
  • Amine fluoride

Topical Fluorides Indications:

• Dental caries prevention
• Caries risk patient
• Desensitization

Topical Fluorides Mechanism:

• Monofluorophosphate gets deposited in the crystalline lattice and intra- crystalline transposition
  • Fluoride is released
  • This replaces the hydroxyl group to form fluorapatite
• Mono fluorophosphate may exchange with the phosphate group in apatite crystals

Topical Fluorides Adverse Effects

• Detergents and flavoring agents
  • Irritate stomach
  • Cause vomiting
• Abrasive
  • Interfere with complete intestinal absorption of fluoride
• Regular ingestion of fluoride by children <6 years
  • Dental fluorosis

2. Mouth Rinses:

• Described by Bibby et al in 1946

Contra-Indications:

• Children less than 6 years of age
• Persons with problems in oro-facial musculature due to which they cannot rinse

Sodium Fluoride Mouth Rinses:

• Formulated at
  • 0.2% concentration- for weekly use
  • 0.05% concentration- for daily use
• Preparation
  • Prepared by dissolving 200 mg sodium fluoride tablet in 5 teaspoons of fresh clean water
  • It can be used for 4 members (2 adults and 2 children)

Mechanism:

• Fluoride forms fluorapatite from hydroxyapatite
• Fluoride inhibits bacterial metabolism and plaque acid formation

Mouth Rinses Indications:

• If the concentration of fluoride in drinking water is
• 0. 3 ppm or less
• Patients with increased caries risk
• School fluoride programs

Mouth Rinses Advantages:

• 30-40% reduction in caries incidence

3. GELS:

• Include
  • Neutral sodium fluoride and acidulated phosphate fluoride with a fluoride concentration of 5000 ppm
  • Stannous fluoride with a concentration of 1000 ppm

GELS Method of Use:

• Brushing for 1 minute with the gel
• Placing several drops in each tray and held in contact with the teeth for 5 minutes

GELS Disadvantages:

• Violate the principle of delivering low concentration of fluoride
• Cause fluoride toxicity
• Tedious to use

Fluorides Short Essays

Question 1. School water fluoridation.
Answer:

• Initiated as a pilot study in 1954 at St. Thomas Virgin Islands, United States
• It is used only if the surrounding areas from which the students come have a low fluoride content
• The concentration of fluoride in the school water is 4.5 ppm in contrast to 1 ppm of the community water supply
• This is to compensate for the reduced water intake

School water fluoridation Advantages:

• About 40% of reduction in DMFT was observed
• No effort is required by the recipient
• Effective public health measure
• Target population-school children
• Quite economical

School water fluoridation Limitations:

• Need for cooperation from school authorities
• Children may not attend all school days
• There is intermittent fluoride exposure
• Limited pre-eruptive benefits to primary teeth
• Possible confrontation by antifluoridation groups
• The cost of installation, supplies, and maintenance compete with other needs of the school budget
• Custodial and backup personnel are required to be trained

Question 2. Defluoridation.
Answer:

• Defluoridation is the process of removing excess naturally occurring fluoride from drinking water in order to reduce the prevalence and severity of dental fluorosis

Defluoridation Methods

1. Ion Exchange Resins:

• Carbion
  • It is a cation exchange resin of good durability and can be used on sodium and hydrogen cycles
• Defluoron 1:
  • A sulfonated sawdust impregnated with 2% alum solution
• Defluoron 2:
  • It is a sulfonated coal using aluminum solution as regenerate

2. Nalgonda Technique:

• This technique is developed in India in 1975
• By National Environmental Engineering Research Institute
• It was constructed in the district of Nalgonda in Andhra Pradesh in the town of Kathri

Nalgonda Technique Procedure:

• Raw water is collected in a tank
• Add alum solution to it

Read And Learn More: Pedodontics Short Essays Question And Answers

• Next, depending on alkalinity add lime
• Stir gently for 10 minutes
• Results in the formation of floes
• Allow it to settle

Nalgonda Technique Advantages:

• Can be used at domestic and community levels
• Manually operated
• Cost-effective
• It meets with standards laid down by the Bureau of Indian Standard

Question 3. Fluoride Toxicity.
Answer:

• It refers to the symptoms manifested as a result of overdosage or excessive administration.

Fluoride Toxicity Types:

1. Acute: Due to single ingestion of large amounts of fluoride
2. Chronic: Due to long-term ingestion of smaller amounts

Fluoride Toxicity Symptoms:

• GIT disturbances
  • Nausea
  • Vomiting
  • Diarrhea

Pain:

• Abdomen
• Extremities
• Difficulty in speech
• Thirst
• Perspiration
• Weak pulse
• Coma
• Convulsion
• Cardiac arrhythmia

Pathological Changes:

• Oral corrosive changes
• Hemorrhagic stomach contents
• Changes in intestine

Fluoride Toxicity Management:

• Administration of Milk or egg
• Lime water
• Aluminum hydroxide gels
• Inducing vomiting

Question 4. Fluoride Varnish.
Answer:

• Commonly used
  • Duraphat
  • Fluorprotector

Fluoride Varnish Composition:

• It is a dichlorosilane-ethyl diflurohydroxysilane
• The Fluoride content is 22.6 mg F/ml.

Fluoride Varnish Application:

• Oral prophylaxis
• Dry the teeth
• Apply varnish with a single tufted small brush first on the lower arch, then on upper
• Maintain it for 4 minutes
• Avoid rinsing, drinking, and eating for 1 hour.

Fluoride Varnish Dose:

• 0.5 ml of dura phat containing 11.3 mg F fluoride
• 0.5 ml of floor protector containing 3.1 mg F fluoride

Fluoride Varnish Mechanism Of Action:

• On application of varnish, results in a reservoir of fluoride ions around the enamel
• Results in deeper penetration of fluoride and formation of fluorapatite

Question 5. Fluoride Dentrifices.
Answer:

Commonly Used Agents:

• Sodium mono fluoro phosphates
• Sodium fluoride

Fluoride Dentrifices Indication:

• Prevention of caries
• Caries – risk patients
• Desensitization

Fluoride Dentrifices Mechanism Of Actions:

Fluoride Dentrifices Procedure:

• Selection of proper dentifrices
• Place a pea size amount of dentifrice on the toothbrush tips
• Proceed with correct brushing.

Question 6. Dean’s Index.
Answer:

Question 7. Topical Fluorides.
Answer:

• Definition: It is used to describe those delivery systems which provide fluoride for a local chemical reaction to exposed surfaces of the erupted dentition

Topical Fluorides Indications:

• Caries active individual
• Children shortly after tooth eruption
• Those who take medication that reduces salivary flow
• After periodontal surgery
• Patients with fixed or removable prosthesis
• Patients with eating disorders
• Mentally and physically challenged individual

Topical Fluorides Classification:

1. Professionally applied products:

• Dispensed by a dental professional
• It includes
  • Sodium fluoride
  • Minimum 4 applications with 2% gives caries reduction of about 30%
• Stannous fluoride
• Used as 8% concentration
• Acidulated phosphate fluoride gel
• Fluoride varnishes
  • Duraphat
  • fluoroprotector

Composition:

• It is a dichlorosilane-ethyl difluoro hydroxy silane
• Fluoride content is 22.6 mg F/ ml

2. Self-administered:

• Fluoride dentifrices
• Sodium fluoride
• Fluoride mouth rinses
• Dentrifices containing monofluorophosphate

Question 8. Miller’s acidogenic theory
Answer:

• Postulated by WD Miller in 1889.
• It states that
  • Acids formed due to the fermentation of dietary carbohydrates by oral bacteria lead to progressive decalcification of the tooth structures with subsequent disintegration of organic matrix
• It states that the process of dental caries involves two stages
  • Initial stage
    • Acid production due to fermentation of carbohydrates by plaque bacteria
  • Late stage
    • Decalcification of enamel followed by dentin by acids
    • This causes total destruction of enamel and den-tin
• According to Miller, the process of caries involves four factors
  • Dietary carbohydrates
  • Micro-organisms
  • Acids
  • Dental plaque

Fluorides Short Answers

Question 1. Duraphat.
Answer:

• It is a fluoride varnish

Duraphat Composition:

• It is a dichlorosilane-ethyl diflurohydroxysilane
• The Fluoride content is 22.6 mg F/ml.

Duraphat Application:

• Oral prophylaxis
• Dry the teeth
• Apply varnish with a single tufted small brush first on the lower arch, then on upper
• Maintain it for 4 minutes
• Avoid rinsing, drinking, and eating for 1 hour.

Duraphat  Dose:

• 0.5 ml of dura phat containing 11.3 mg F fluoride

Question 2. Mechanism of fluoride varnish.
Answer:

• On application of varnish, results in a reservoir of fluoride ions around the enamel
• Results in deeper penetration of fluoride and formation of fluorapatite

Question 3. Brudevold’s technique.
Answer:

• It is a method of preparing APF gel
• It is prepared by dissolving 20 gms. of sodium fluoride in 1 liter of 0.1M phosphoric acid
• Followed by the addition of 50% hydro fluoride acid
• A gelling agent methylcellulose or hydroxyethyl cellulose is added to the solution

Question 4. Choking off phenomenon.
Answer:

• It is seen on the application of 2% of sodium fluoride
• When sodium fluoride is applied a layer of calcium fluo¬ride gets formed
• This interferes with the further diffusion of F to react with hydroxyapatite
• This is called choking-off phenomenon

Question 5. Sodium Fluoride Mouth washes.
Answer:

Sodium Fluoride Mouthwashes Preparation:

• Dissolving 200 mg NaF tablet in 5 teaspoons of fresh clean water

Sodium Fluoride Mouthwashes Method Of Use:

• Rinse daily with 1 teaspoon after brushing
• Rinse for 60 seconds
• Then expectorant

Sodium Fluoride Mouthwashes Advantages:

• 30-40% reduction in DMFT

Question 6. Shoe Leather survey.
Answer:

• Conducted by Dr HTrendley Dean
• It was conducted in 97 localities
• It was done with the help of a questionnaire

AIM:

• To find the level of fluoride at which the tooth starts to blemish

Question 7. Dental Fluorosis.
Answer:

Etiology:

• Excessive intake of fluoride during tooth development

Features:

• Lustreless enamel
• Opaque white patches
• The mottled, striated, and pitted surface
• Yellow/brown stains
• Enamel hypoplasia

Fluorides Viva Voce

1. Safely tolerated dose – 8-16 mg/kg body weight
2. Toxic dose – 16-32 mg/kg body weight
3. Lethal dose – 32-64 mg/kg body weight
4. Fluoride varnishes are applied once in six months
5. Knutson’s technique is recommended at the age of 3, 7,11, and 13 years
6. APF solution is also known as Brudevold solution
7. The premolar is most commonly affected tooth by fluorosis
8. Duraphat is the most effective varnish in caries reduction
9. Chronic toxicity includes dental fluorosis and skeletal fluorosis