History
Natural Sources Of Fluoride
Physiology and metabolism of fluoride
Fluoride in Dentistry
Control of dental caries
Fluoride toxicity
Dental fluorosis
Fluorosis indices
Water defluoridation
Conclusion
History
Natural Sources Of Fluoride
Physiology and metabolism of fluoride
Fluoride in Dentistry
Control of dental caries
Fluoride toxicity
Dental fluorosis
Fluorosis indices
Water defluoridation
Conclusion
This presentation is all about the systemic administration of fluorides ,as it is an easier way for the administration of fluorides to prevent dental caries and tooth decay.the aim is to explain the advantages of systemic fluoride ,their present status in India and in other countries and to create awareness among population.Also raising an issue that how these methods of systemic fluoride administration can be improved so that there is better prevention of decay problems
overview of flouride with detailed information on their pharmacological action, mechanism, uses and adverse effect for both medical and dental students.
The role of fluoride and chlorhexidine in the prevention of dental cariesDeepa jinan
a detailed description of the role of fluoride and chlorhexidine in the prevention of dental caries, including mehanism of action, modes/ routes of administration, dose recommendations, comparisons.
Fluoride is often called as sword as an expression for anything that can simultaneously help & hinder .
Accumulated evidence from numerous studies show that the prolonged use of fluoride at recommended levels doesn't produce harmful physiological effects in human.
Inadequate ingestion of fluoride is associated with dental caries & an extensive intake of fluoride can lead to dental & skeletal fluorosis
Acute ingestion of fluoride in large quantities may be followed by rapidly developing signs and symptoms which may result in death
There is substantial evidence that fluoride, through different applications and formulas, works to control caries development. The first observations of fluoride's effects on dental caries were linked to fluoride naturally present in the drinking water, and then from controlled water fluoridation programs. Other systemic methods to deliver fluoride were later suggested, including dietary fluoride supplements such as salt and milk. These systemic methods are now being questioned due to the fact that many studies have indicated that fluoride's action relies mainly on its post-eruptive effect from topical contact with the tooth structure. It is known that even the methods of delivering fluoride known as 'systemic' act mainly through a topical effect when they are in contact with the teeth. The effectiveness of water fluoridation in many geographic areas is lower than in previous eras due to the widespread use of other fluoride modalities. Nevertheless, this evidence should not be interpreted as an indication that systemic methods are no longer relevant ways to deliver fluoride on an individual basis or for collective health programs. Caution must be taken to avoid excess ingestion of fluoride when prescribing dietary fluoride supplements for children in order to minimize the risk of dental fluorosis, particularly if there are other relevant sources of fluoride intake - such as drinking water, salt or milk and/or dentifrice. Safe and effective doses of fluoride can be achieved when combining topical and systemic methods.
HISTORY & MECHANISM OF ACTION SYSTEMIC FLUORIDES.pptxRUCHIKA BAGARIA
EVERYTHING YOU NEED TO KNOW ABOUT SYSTEMIC FLUORIDES.
HISTORY, MECHANISM OF ACTION, METABOLISM, DIETARY SUPPLEMENTS AND RECENT ADVANCES.
LETS STUDY SYSTEMIC FLUORIDE TOGETHER.
LETS LEARN AND SHARE OUR KNOWLEDGE.
This presentation is all about the systemic administration of fluorides ,as it is an easier way for the administration of fluorides to prevent dental caries and tooth decay.the aim is to explain the advantages of systemic fluoride ,their present status in India and in other countries and to create awareness among population.Also raising an issue that how these methods of systemic fluoride administration can be improved so that there is better prevention of decay problems
overview of flouride with detailed information on their pharmacological action, mechanism, uses and adverse effect for both medical and dental students.
The role of fluoride and chlorhexidine in the prevention of dental cariesDeepa jinan
a detailed description of the role of fluoride and chlorhexidine in the prevention of dental caries, including mehanism of action, modes/ routes of administration, dose recommendations, comparisons.
Fluoride is often called as sword as an expression for anything that can simultaneously help & hinder .
Accumulated evidence from numerous studies show that the prolonged use of fluoride at recommended levels doesn't produce harmful physiological effects in human.
Inadequate ingestion of fluoride is associated with dental caries & an extensive intake of fluoride can lead to dental & skeletal fluorosis
Acute ingestion of fluoride in large quantities may be followed by rapidly developing signs and symptoms which may result in death
There is substantial evidence that fluoride, through different applications and formulas, works to control caries development. The first observations of fluoride's effects on dental caries were linked to fluoride naturally present in the drinking water, and then from controlled water fluoridation programs. Other systemic methods to deliver fluoride were later suggested, including dietary fluoride supplements such as salt and milk. These systemic methods are now being questioned due to the fact that many studies have indicated that fluoride's action relies mainly on its post-eruptive effect from topical contact with the tooth structure. It is known that even the methods of delivering fluoride known as 'systemic' act mainly through a topical effect when they are in contact with the teeth. The effectiveness of water fluoridation in many geographic areas is lower than in previous eras due to the widespread use of other fluoride modalities. Nevertheless, this evidence should not be interpreted as an indication that systemic methods are no longer relevant ways to deliver fluoride on an individual basis or for collective health programs. Caution must be taken to avoid excess ingestion of fluoride when prescribing dietary fluoride supplements for children in order to minimize the risk of dental fluorosis, particularly if there are other relevant sources of fluoride intake - such as drinking water, salt or milk and/or dentifrice. Safe and effective doses of fluoride can be achieved when combining topical and systemic methods.
HISTORY & MECHANISM OF ACTION SYSTEMIC FLUORIDES.pptxRUCHIKA BAGARIA
EVERYTHING YOU NEED TO KNOW ABOUT SYSTEMIC FLUORIDES.
HISTORY, MECHANISM OF ACTION, METABOLISM, DIETARY SUPPLEMENTS AND RECENT ADVANCES.
LETS STUDY SYSTEMIC FLUORIDE TOGETHER.
LETS LEARN AND SHARE OUR KNOWLEDGE.
Fluorides in the environment, history, mechanism of action of fluorides, Systemic fluoridation in water, salt, milk and fluoride supplements. History of each water, milk and salt fluoridation.
Topical fluoride is very important to decrease or arrest dental caries. Fluroides are topical and systemic. Fluorides prevents caries in children. There are various forms fluorides available in market . Fluridated toothpastes, mouthrinses, tablets.
It is generally accepted that a low level of fluorine in mains water 0.4 to 1 mg -¢ L – 1 depending on the climate of the country concerned promotes the formation of tooth enamel and protects teeth from decay. On the other hand, too much fluorine will destroy this enamel and cause a range of endemic type disorders that are generally called “fluoroses- malformed teeth, staining of the enamel, decalcification, tendon mineralisation, digestive and nervous disorders, etc. These problems can appear in individuals for widely variable quantities of the product. Water must be discharged or treated as soon as it contains more than 1 to 1.5 mg -¢ L – 1 of F – . Some natural waters contain more than 10 mg -¢ L – 1 of fluorine. This concentration has to be reduced to approximately 1 mg -¢ L – 1 the acceptable concentration falling as the average annual temperature rises the European standard has set 1.5 mg -¢ L – 1. Many studies have been carried out to address the issue however little success has been reported up to date. Layered double hydroxides LDHs which readily undergo anion exchange reactions have been used as a suitable candidate for defluorination. Also there is regeneration of the material after removal of fluoride ions without releasing flouride ions back in to the water cycle. F elimination using a nanofiltration NF operation will solve problems for large scale pilot plants in the future.Many defluorination projects have significant effectiveness on the prevention of endemic fluorosis. The concentrations of water fluoride were below 1 mg L. Advanced on site methods, such as under sink reserve osmosis units, can remove fluoride but are too expensive for developing areas. Calcium carbonate as a cost effective sorbent for an onsite defluorination drinking water system. Batch and column experiments have been performed to characterize F removal properties. The present review discusses various techniques of defluorination of water. Dr. Atul Kumar Sharma | Dr. Harsukh Ram Chharang "Defluorination of Drinking Water" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-5 | Issue-5 , August 2021, URL: https://www.ijtsrd.com/papers/ijtsrd46324.pdf Paper URL: https://www.ijtsrd.com/chemistry/other/46324/defluorination-of-drinking-water/dr-atul-kumar-sharma
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and
offering a wide range of dental certified courses in different formats.
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and
offering a wide range of dental certified courses in different formats.
DENTAL FLUOROSIS: A CASE STUDY IN VAUVNIYA DISTRICT, DRY ZONE OF SRI LANKASivanesan Somanathar
Abstract: High fluoride contents in ground water are very big problem in the dry zone of Sri
Lanka. Fluoride and some other parameters determined in the ground water sample. Study has been
made of groundwater of 72 wells at five villages of the Vavuniya district in Northern Province, Sri
Lanka, with special focus on fluorine contamination. Study area 90 people were examined and 23 of
them were identified to be affected by dental fluorosis. The samples were collected on during the
period of February and March. Fluoride concentration was determined using UV visible
spectrophotometer and Field measurements of temperature, pH, and electrical conductivity were
made during sampling. Fluoride concentrations in the study area vary from 0.14 to 1.52 mg/L, water
table range from 3.9m to7.3m respectively. Electrical conductivity range from 120μs/cm to
1952μs/cm. out of the 72 wells only six wells were observed with higher F concentration than the
WHO standard maximum (1.5mg/L) level. However, F concentration of 32wells higher than the
desirable (0.6mg/L) level of WHO. Elevated fluoride concentrations in shallow groundwater in
intensive agricultural areas appear to be related to the leaching of fluoride from soils due to successive
irrigation and flooding time.
Benign, locally aggressive tumor of odontogenic epithelium, Previously called adamantinoma, Second most common odontogenic tumor after odontoma, Mandible is most common site, Usually asymptomatic and can be found incidentally on routine dental examinations
Title: Sense of Taste
Presenter: Dr. Faiza, Assistant Professor of Physiology
Qualifications:
MBBS (Best Graduate, AIMC Lahore)
FCPS Physiology
ICMT, CHPE, DHPE (STMU)
MPH (GC University, Faisalabad)
MBA (Virtual University of Pakistan)
Learning Objectives:
Describe the structure and function of taste buds.
Describe the relationship between the taste threshold and taste index of common substances.
Explain the chemical basis and signal transduction of taste perception for each type of primary taste sensation.
Recognize different abnormalities of taste perception and their causes.
Key Topics:
Significance of Taste Sensation:
Differentiation between pleasant and harmful food
Influence on behavior
Selection of food based on metabolic needs
Receptors of Taste:
Taste buds on the tongue
Influence of sense of smell, texture of food, and pain stimulation (e.g., by pepper)
Primary and Secondary Taste Sensations:
Primary taste sensations: Sweet, Sour, Salty, Bitter, Umami
Chemical basis and signal transduction mechanisms for each taste
Taste Threshold and Index:
Taste threshold values for Sweet (sucrose), Salty (NaCl), Sour (HCl), and Bitter (Quinine)
Taste index relationship: Inversely proportional to taste threshold
Taste Blindness:
Inability to taste certain substances, particularly thiourea compounds
Example: Phenylthiocarbamide
Structure and Function of Taste Buds:
Composition: Epithelial cells, Sustentacular/Supporting cells, Taste cells, Basal cells
Features: Taste pores, Taste hairs/microvilli, and Taste nerve fibers
Location of Taste Buds:
Found in papillae of the tongue (Fungiform, Circumvallate, Foliate)
Also present on the palate, tonsillar pillars, epiglottis, and proximal esophagus
Mechanism of Taste Stimulation:
Interaction of taste substances with receptors on microvilli
Signal transduction pathways for Umami, Sweet, Bitter, Sour, and Salty tastes
Taste Sensitivity and Adaptation:
Decrease in sensitivity with age
Rapid adaptation of taste sensation
Role of Saliva in Taste:
Dissolution of tastants to reach receptors
Washing away the stimulus
Taste Preferences and Aversions:
Mechanisms behind taste preference and aversion
Influence of receptors and neural pathways
Impact of Sensory Nerve Damage:
Degeneration of taste buds if the sensory nerve fiber is cut
Abnormalities of Taste Detection:
Conditions: Ageusia, Hypogeusia, Dysgeusia (parageusia)
Causes: Nerve damage, neurological disorders, infections, poor oral hygiene, adverse drug effects, deficiencies, aging, tobacco use, altered neurotransmitter levels
Neurotransmitters and Taste Threshold:
Effects of serotonin (5-HT) and norepinephrine (NE) on taste sensitivity
Supertasters:
25% of the population with heightened sensitivity to taste, especially bitterness
Increased number of fungiform papillae
Pulmonary Thromboembolism - etilogy, types, medical- Surgical and nursing man...VarunMahajani
Disruption of blood supply to lung alveoli due to blockage of one or more pulmonary blood vessels is called as Pulmonary thromboembolism. In this presentation we will discuss its causes, types and its management in depth.
Couples presenting to the infertility clinic- Do they really have infertility...Sujoy Dasgupta
Dr Sujoy Dasgupta presented the study on "Couples presenting to the infertility clinic- Do they really have infertility? – The unexplored stories of non-consummation" in the 13th Congress of the Asia Pacific Initiative on Reproduction (ASPIRE 2024) at Manila on 24 May, 2024.
ARTIFICIAL INTELLIGENCE IN HEALTHCARE.pdfAnujkumaranit
Artificial intelligence (AI) refers to the simulation of human intelligence processes by machines, especially computer systems. It encompasses tasks such as learning, reasoning, problem-solving, perception, and language understanding. AI technologies are revolutionizing various fields, from healthcare to finance, by enabling machines to perform tasks that typically require human intelligence.
Explore natural remedies for syphilis treatment in Singapore. Discover alternative therapies, herbal remedies, and lifestyle changes that may complement conventional treatments. Learn about holistic approaches to managing syphilis symptoms and supporting overall health.
Prix Galien International 2024 Forum ProgramLevi Shapiro
June 20, 2024, Prix Galien International and Jerusalem Ethics Forum in ROME. Detailed agenda including panels:
- ADVANCES IN CARDIOLOGY: A NEW PARADIGM IS COMING
- WOMEN’S HEALTH: FERTILITY PRESERVATION
- WHAT’S NEW IN THE TREATMENT OF INFECTIOUS,
ONCOLOGICAL AND INFLAMMATORY SKIN DISEASES?
- ARTIFICIAL INTELLIGENCE AND ETHICS
- GENE THERAPY
- BEYOND BORDERS: GLOBAL INITIATIVES FOR DEMOCRATIZING LIFE SCIENCE TECHNOLOGIES AND PROMOTING ACCESS TO HEALTHCARE
- ETHICAL CHALLENGES IN LIFE SCIENCES
- Prix Galien International Awards Ceremony
3. Fluoride
• Latin “fluor”- flow or flux
• Symbol- “F”
• Atomic no.- 9
• Atomic weight- 18.99
• It is a pale yellow, corrosive gas, which reacts with practically
all organic and inorganic substances
• Most electronegative of all elements
• Fluoride containing minerals-
• Fluorspar (CaF2
• Cryolite (Na3AlF6 ) – rare
• Fluorapetite Ca10(PO4 )6F2
3
4. HISTORY
• Four separate periods or phases:
• (1) Clinical discovery phase,
• (2) Epidemiologic phase,
• (3) Demonstration phase, and
• (4) Technology transfer phase
4
5. Clinical discovery phase
1.stains could not be polished away
• intrinsic, or
• incorporated into the enamel structure
2. not everyone’s enamel had these characteristics
• Present in long term residents, individual who had been born there,
• Individual who had come there as babies
• But not present among individuals who had not lived in the vicinity
as young children led McKay to believe that the etiologic or causal
agent was environmental in nature and was incorporated into the
enamel structure at the time of tooth formation.
5
The first period,
1901 to 1933, was characterized by the pursuit of knowledge to determine the cause of developmental enamel defects
present in people in certain western areas of the United States
In 1901, Dr. Frederick McKay, noticed -discolored enamel that sometimes exhibited surfaces that were rough, uneven,
or even pitted. Local residents called this condition “Colorado Brown Stain.”
McKay made two important observations about this enamel defect:
6. McKay named this condition “mottled enamel” and noted minute white
flecks or yellow or brown spots or areas, scattered irregularly or streaked
over the surface of a tooth or it may be a condition where entire tooth
surface is of dead paper white like color of china dish
1909 - McKay sought the consultation of Dr. G. V. Black, well‐known and
respected researchers
publishing their observations in Dental Cosmos, the premier national dental
journal
Black’s histological finding – an endemic imperfection of enamel in teeth
Over several decades, McKay examined children in various nearby
communities and other states to determine the extent of the condition in
the population.
Demonstrate that mottled enamel was confined to specific geographic areas
6
7. 1920’s McKay noted the etiologic agent had to be a constituent of some community water supplies, despite the fact that
chemical analyses all failed to identify likely constituents (most prevalent where deep artesian wells)
In communities such as Andover and Britton, South Dakota, where he found severe mottling, he advised mothers to
obtain their children’s drinking water from sources other than the community supply.
He advised the citizens of Oakley to abandon their old supply and tap this spring for a new source, which the community did in
1925. McKay was right, for children born in Oakley subsequent to the change were free of mottled enamel.
1927, McKay published an important corollary finding: People who had enamel fluorosis also experienced less dental decay
Early 1930s, H. V. Churchill, a chemist with the Aluminum Company of America, used a new method of spectrographic analysis
Of water McKay contacted Churchill and sent him samples of water from Colorado Springs and other areas he had observed to
have a high prevalence of mottled enamel.
The results showed fluoride concentrations ranging from 2 ppm F to 12 ppm F.
Similar findings were reported by investigators at the University of Arizona161 and by a veterinary group in Morocco, then still
a French colony, that was studying le darmous, the local name given to an extreme degree of mottled enamel found in
Moroccan sheep. 7
8. The role of fluoride in the cause of enamel fluorosis and the prevention of dental caries led to the second period, known as the
epidemiologic phase, which lasted from 1933 to 1945
Appointment of Dr. H. Trendley Dean, a commissioned officer in the U.S. Public Health Service
Dean’s job was to map out the prevalence of mottled enamel across the country and to look for a way to reduce or
eliminate it.
He wrote to dental societies across the country asking for their input regarding fluorosis in their locale;
In 1933, he published his first map showing the prevalence of mottled enamel in the United States
By the mid‐1930s, he began using the term fluorosis to replace mottled enamel.
In 1934, Dean developed the Community Fluorosis Index that allowed collection and mapping of severity data in addition to
prevalence data.
This index assessed not only the location of the condition but also its severity.
Dean later modified the index to classify the full range of enamel conditions from fine, lacy markings to stained, pitted,
damaged enamel
8
Epidemiologic phase
9. Researchers began looking at the relationship of fluoride in the water
and tooth decay.
Dean conducted some impressive epidemiologic studies, including
the “4 city study” and “Dean’s 21‐Cities Study.”
The 4 city study highlighted the difference in dental health and
fluorosis among four Illinois cities with differing concentrations of
fluoride in the water supply
In the 21‐city study, Dean examined the data collected by teams of
researchers who had examined the teeth of children residing in 21
different communities that had varying levels of naturally occurring
fluoride in the drinking water.
Study showed that
(1) higher concentrations of fluoride in the water correlated with
fewer teeth affected by dental caries
in children, constituting an inverse relationship between the level of
natural fluoride in the water and the prevalence of
dental caries and
(2) higher levels of fluoride were associated with more children with
fluorosis of the teeth, meaning that
a direct relationship existed between the level of natural fluoride in
the water and the prevalence of enamel fluorosis 9
10. Dean’s results showed that both a reduction of dental caries and an acceptable level of enamel fluorosis could be attained
with water containing fluoride levels at approximately 1 ppm of fluoride.
At this level, substantial reductions in dental caries of up to 60% were observed with approximately 10% of the population
exhibiting very mild enamel fluorosis.
The unattractive form of fluorosis, often called mottling, that was associated with higher levels of fluoride was not
observed to occur at the level of 1 ppm F.
Consequently, 1 ppm F became the benchmark level, and was used by the U.S. Public Health Service in
1962 in establishing the optimal range: 0.7 ppm F to 1.2 ppm F.
The optimal fluoride level seeks to maximize the benefits of dental caries reduction and minimize the probability of enamel
fluorosis
Mottling
Widespread 3ppm
Discrete pitting 4 ppm
Less in case of 2.5 to 3ppm
No mottling in 1 ppm
10
11. Demonstration phase
11
• third period
• began in January 1945
• was characterized by a series of community trials in which fluoride levels were adjusted in the public drinking water
supply
• On January 25, 1945, Grand Rapids, Michigan, became the first city in the world to fluoridate its drinking water
• The demonstration phase lasted until about 1954
• at that time, the benefits of the optimal adjustment of fluoride levels in drinking water became so apparent that many
U.S. cities began fluoridation programs for their citizens
12. Technology transfer phase
Fourth phase
began about 1950
characterized by the establishment of a set of national health goals, which include fluoridation
In 1969, WHO advocated that 1 ppm of fluoride in community water supplies was a practical and effective public health
measure
12
13. 1901- Dr.
Fredrick Mckay
Colorado stain
Mottled stain 1909- Mckay with G.V. black
An endemic imperfection of
enamel
1912 Dr. JK eager
Denti di chiaie
1918 Mc kay confirmed
mysterious element to
be present in water
1931 spectrographic
analysis
Presence of fluoride
1934
Dean’s index of
fluorosis
1931 Dr. Trendley
Dean
1942 Dean et al
1ppm fluoride
decreases caries 60%
1969 WHO
1ppm fluoride
1945 artificial fluoridationFluoride as
essential
element
14. Fluoride in environment
14
lithosphere
•Fluoride is widely distributed
•300ppm
•Concentration of fluoride is increased in highly siliceous igneous rocks, alkali rock eg. Fluorspar,
fluorapatite
biosphere
•Plants 2-20mg/gm of dry weight
•Leafy vegetable as cabbage, lettuce, brussel 11-26mg
•Tea plant highest fluoride concentration
•Fish 20ppm
hydrosphere
•Water contains varying concentration
•Highest of about 2800ppm lake nakura in kenya
•Surface water has less fluoride compared to ground water
atmosphere
•Fluoride emission heaviest in vicinity of industries- in production of aluminum
15. SOURCES OF FLUOR
From fish by population –fish is diet --- 0.5mg/day
Fish (salmon, sardines) fluoride content 20-40mg/day
Jower, banana, potatoes ----substantial quantities of fluoride
Plants – taro, yams-----high fluoride
Rock salts 40 to 200ppm
Dried tea leaves 100 – 400ppm
Tea drinkers 0.04 to 2.7mg/day
Drugs
diuretics, fluorosteroids, phenothiazine
Mineral water ---- 1.5 to 7ppm
15
16. METABOLISM
Absorption
Distribution
Elimination
Blood plasma – central compartment
50% of ingested fluoride will be excreted in urine
Rest 50% will be taken by mineralized tissues
Hard tissue- fluoride is reversibly bound and can be released in remodeling of bone
Soft tissues – steady state distribution between extra and intracellular fluids
Major route of fluoride elimination is kidney
16
17. Absorption
Introduction to absorption
Major route is gastrointestinal tract ( stomach and small intestine)
fluoride may be
Water soluble fluorides(most) Less soluble fluorides-
NaF, HF, H2SiF6 , Na2PO3F CaF2 , Ca10(PO4 )6F2
ionic form ( inorganic or free fluoride)
In plasma fluoride is in 2 forms non ionic form ( bound fluoride)
Absorption depend on
Physical and chemical properties of compound
Solubility
Amount of fluoride ingested
Other dietary constitutes such as calcium which form insoluble salts with fluoride
17
18. Rate and degree of absorption
NAF- rapidly absorbed
height of plasma peak α fluoride dose
height of plasma peak α rate of absorption
height of plasma peak 1/ α body weight ( volume of distribution)
Time of occurance of plasma peak is independent of amont of fluoride
18
19. Mechanism and site of absorption
Passive absorption
Mechanism and rate of gastric absorption
related to
gastric acidity
Ionic fluoride acidic environment converted to HF
H+ + F- HF
These are the uncharged molecule which easily pass via biological membrane (gastric mucosa)
19
20. Absorption from food and dental fluoride preparation
dietary fluoride is well absorbed - increase bioavailabilty
Topical fluoride- when swallowed absorbed completely
bioavailability of NaF is 100 %
calcium containing abrasive reduces rate and degree of absorption
Fluoride varnish remain in tooth surface for upto 12 hrs
A thorough rinsing of mouth after toothbrusing will minimize the ingestion of fluoride
20
21. Pharmacokinetics of fluoride
An initial increase
Rapid fall for 1 hr ( early phase / distribution absorption of fluoride distribution to soft tissues
Phase- a phase) from gastrointestinal tract
Slower decline( representing elimination elimination phase
Phase – b phase)
Plasma half life of fluoride is 4-10 years (time
For which plasma fluoride concentration fall
By one half)
21
23. DISTRIBUTION
Fluoride in soft tissues
Determined by blood flow
Steady rate fluoride concentration
Plasma fluoride concentration ratio 0.4 to 0.9 regardless of rate
23
24. Bone:
99% of all fluoride in human body is found in calcified tissues
-Total amount-2.6mg
-Most of F in the body retained in the skeleton-
-vary according to the renal clearance
- F enter in mineralized tissue-replacing 0H- , C03 2- and HC03
-Remodeling bones deposit more fluoride than older people
-Fluoride deposition is a reversible process
24
25. TEETH
Concentration of fluoride was the highest in the outermost layer of the enamel, and there was a marked decrease in
concentration from the surface to a distance of 100-200μm. In the middle and inner third of the enamel, concentration
tended to level off with a small increase at a distance of 50μm adjacent to the enamel dentine junction (EDJ)
A higher level of fluoride in the coronal dentine than in the enamel was observed at the enameldentine junction (EDJ), and
it continued to a distance of about 300μm from the pulpal surface of the coronal dentine. There was a great increase of
fluoride concentration in the coronal dentine near the pulp. The level of fluoride increased with age.
Fluoride concentration was maximal at or near the surface of the cementum and decreased toward the interior of the
cementum. There were different types of fluoride distribution in the cementum. The level of fluoride concentration
increased with age.
Concentration of fluoride decreased after cementum-dentine junction (CDJ), reached the lowest value in the middle of the
root dentine, and rose again toward the surface of the pulpal dentine.
25
26. Although Total Fluoride, Average Fluoride, and Maximum Fluoride in the enamel showed no clear tendency of increase
with age, those of the coronal dentine increased with age until a plateau was reached at about 50 years.
Increases in Total Fluoride, Average Fluoride, and Maximum Fluoride in both root dentine and cementum continued to a
higher age of the tooth than in the coronal dentine. Particularly, Total Fluoride increased in the cementum more than in any
other tissues examined
It was concluded that, although the fluoride concentration in the enamel could have been changed due to its post-eruptive
environment, the coronal dentine takes up fluoride from the pulp until about the age of 50 and the root dentine and the
cementum take up fluoride from both the pulp and the periodontal ligament all during the life of the tooth
26
27. • highest fluoride
• decreases by 1/10th
• slight increase
• less as less vascular
• highest fluoride as its vascular
29. Excretion of fluoride
Renal clearance of fluoride
Excretion via breast milk and saliva
Excretion via faeces and sweat
Renal clearance of fluoride
chief organ of excretion- kidney
Because ionic fluoride is not bound to plasma proteins, its concentration in the glomerular filtrate is the same as that of
plasma water
After entering the renal tubule, a variable amount of the ion will be reabsorbed and returned in systemic circulation
The reminder will be excreted in urine
Hence the first determinent of fluoride excreted in urine is determined by GFR
Renal clearance of fluoride in adult is 30-50 ml/ min
It depends on
1. urinary pH
2. urinary flow rate
‘
29
30. high urinary flow alkaline urine
rapid clearance chronic renal failure
low urinary flow acidic urine increased plasma and bone fluoride level
slow clearance
Normal kidney excrete 50% about fluoride GFR
30% excreted in 6 hrs
60% of fluoride excreted in 24 hr
30
31. Excretion via breast milk and saliva
Fluoride concentration of colostrum and mature breast milk is reported to be same about 0.4 uM
No diurnal variation
Excretion via faeces and sweat
less quantitative importance
Concentration of fluoride in sweat is in range of 0.067 – 0.5 ppm
Faecal excretion 8% to total intake and 10% of urinary output
31
33. Estimation of fluoride concentration
Collection of sample
Flouride analysis
Method of fluoride analysis in food
flow rate exhibit circadian rhythm
Collection of sample
saliva
mechanical
(chewing inert wax) stimulated unstimulated
or use if citric acid
microorganism and desquamated epithelial cell
separation by centrifugation
Analysis 33
34. Fluoride analysis
fluoride
ionic bound
commonly used method made free to ionic state before final measurement
For estimation of fluoride distillation, wet and dry ashing, acid extraction
Specific ion electrode
Isotachophoresis and ion chromatography
34
35. Method of fluoride analysis in food
performed by potentiometric measurement with aid of fluoride ion specific electrodes
Perchloric acid diffusion
Simple diffusion
Silanol extraction
Most reliable is microdiffusion technique
35
36. Micro diffusion technique
One day diffusion at 25 ̊C with hexamethyl-di- siloxane (HMDS)
into
o.1ml of 0.65m NaOH
dried
added to 0.5 ml of 0.66 M acetic acid
Solution applied to fluoride electrode
analysis 36
38. References
Essentials of public health dentistry – soben peter
Primary Preventive Dentistry Norman O. Harris
Dentistry, dental practise and the community –brain a. burt
https://www.jstage.jst.go.jp/article/jdh1952/36/3/36_3_276/_article/-char/en
https://www.researchgate.net/figure/Flowchart-of-fluoride-metabolism_fig1_238595692
38