Fluorides third year class


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Fluorides third year class

  2. 2. CONTENT  Introduction  Historical evolution of fluorides  Fluoride chemistry and occurrence  Total intake of fluoride  From Air  From Water  From Food  Fluoride metabolism and bioavailability  Physiologic distribution of fluoride  In blood and soft tissue  In hard tissue
  3. 3.  Excretion of fluoride  Placental transfer of fluoride  Water fluoridation  School water fluoridation  Fluoride tablets  Fluoridated salt  Fluoridated milk  Fluoridated flour and sugar  Toxicity of fluoride  Defluoridation
  4. 4. HISTORY  In 1805, Morichini found fluoride in human Enamel.  Fluorine discovered by chemist Scheele in 1771- isolated by Moissan in 1886  First report of fluoride concentration in drinking water quoted in ppm given by Hillebrand.  Desirabode in 1847 referred to fluates-(silicate or fluate of lime and alumine, dried and pulverized)  First reference to prophylactic role of fluoride made by Erhadt in 1874  Fluoride pills (KF) recommended in England, comes in pleasant tasting form as “hunter pills”  Dr A. Denninger (1896)- Fluoride an agent to combat dental disease and Appendicitis
  5. 5.  In 1901 Dr. Federick Mckay- “Colorodo Stains” minute white flecks, yellow or brown spots scattered..  In 1902 Dr. J.M. Eager noticed in Italian emigrants -“denti di chiaie”  1916, Dr. Green supported Mckay work with histologic evidence “ an endemic imperfection of the enamel of the tooth  In 1918 Dr. O. E. Martin and Mckay- Britton (1898) changed water supply from shallow wells to deep drilled artesian wells….  1931 Mr. H. V. Churchill- spectrographic analysis of Bauxite city water 13.7ppm
  6. 6.  in 1933, Dr. H. Trendley Dean- conducted “Shoe Leather Survey” in 97 localities, with a aim to find out minimal threshold level….  In 1939 came out with ‘domestic water is primary cause of human mottled enamel ( dental fluorosis)’  In the same year- hypothesis showing ‘inverse relationship between endemic fluorosis and dental caries’
  7. 7. Fluoride chemistry & occurrence -  Greek “floris”- destruction  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
  8. 8.  Reasons for high reactivity:- 1s2, 2s2, 2p5  Most electronegative of all elements  Small size of atom  High electron affinity  Small bond length
  9. 9.  17th in order of abundance of all elements  Constitutes about 0.032% in earth’s crust  Fluoride containing minerals-  Fluorspar (CaF2) - 48.8%  Cryolite (Na3AlF6) – rare  Fluorapetite Ca10(PO4)6F2- 3.8%
  10. 10. Fluoride In Air  HF or Gaseous F2  Dust of f2 containing soils, gaseous industrial, coal smoke, and volcanic emulsion.  Levels of air borne- Aluminum factories: 5micro grams/ m3
  11. 11. Fluoride in plants  Roots form soil and Leaves form air  Camellia sinensis –acidic soils,  Indian Tea leaves – 70 to 375 ppm  Vegetables- factories- 10ppm  Fruits and vegetables- 0.2 to 0.5 microgram/gram wet wt. grown near aluminums
  12. 12. Fluoride In Animal Products  Beef, pork and mutton-0.3ppm  Higher in Chicken- contamination bone and cartilage fragments  Fish products- up to 20ppm  Dried sea foods also fluoride rich 84.5ppm (South East Asia)
  13. 13. Fluoride In Beverages  Ranges from 0.05 to 1.05 ppm  Fluoride content in alcoholic beverages generally reflects that of water used.
  14. 14. Total daily intake of fluoride Fluoride from Air  Minimal Fluoride from Water  Most important single source of fluoride  Dependent on fluoride concentration and amount  Fluctuation –climatic and geographical areas Fluoride from food  0.3 to 0.6 mg/day  Fluoride intake 6months of life-bottle/breast fed  Breast fed infant receives 0.003 to 0.004mg/day- formula fed infants (1.2ppm) fluoride intake increased 50 times
  15. 15.  Excessive consumption of tea and sea foods- increased flr  National Research Council 1980 – safe and adequate 1.5 to 4.0 mg/day in adults 0.05 to 0.07 mg/day in children for optimal dental health Threshold level drinking water 2.0ppm- dental fluorosis
  16. 16. Fluoride metabolism & Bioavailability  Therapeutic action and safety of fluoride – kinetic process Mechanism and site of absorption:-  Water soluble fluorides- NaF, HF, H2SiF6, Na2PO3F and StF  Less soluble fluorides- CaF2 , Ca10(PO4)6F2  Passive in nature  Rapid absorption stomach- nonionic diffusion of HF  Ph of gastric fluid-free F in the form of HF  With milk, F bioavailability decreased..  Formation of low soluble calcium fluoride  Binding to casein and colloidal calcium phosphate  Clotting of milk (acidity)-physical barrier over mucosal
  17. 17.  Absorption from solid foods is less compare to liquid  80% of ingested is absorbed From fluoride preparation and dental materials:-  Dentifrices- less  Alginate (4450 to 24,240 ppm)- systemic absorption peak in 30 min Single impression Zelgan- 119ng/ml in plasma level Double impression -200ng/ml 150 ng/ml from 3mg F in aqueous solution  Fluoridated anesthesia- halothane, Methoxyfluorane, Enflurane -630ng/ml
  18. 18. PHYSIOLOGIC DISTRIBUTION OF FLUORIDE Fluoride in Blood:-  Blood plasma is most reliable indicator  ¾ in plasma and ¼ in RBC  Fluoride exists in both forms -bounded from -ionic form- varies concentration F in drinking water  Increase in plasma F with age and in presence of renal failure Drinking water 0.25 or 1.25 ppm –plasma level 0.01 or 0.025ppm Increased reactive sites and voids in old bone is more saturated and filled with F than young bone
  19. 19. Fluoride In Soft Tissue  Tissue/ plasma ratio = 0.4 to 1  Ectopic calcification loci- F accumulation in Aorta, tendon, cartilage and placenta
  20. 20. Effects On Kidney  Fluoride is normally cleared from the blood by deposition in bone, excretion in urine- unable to find toxic effect on kidney endemic fluorosis.  Patients with chronic renal failure- dialysed with fluoridated have additional load of fluoride So fluoride free water is used for kidney dialysis
  21. 21. Bone:-  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
  22. 22. Teeth:-  Deposition occurs in successive stages. Initial deposition – organic and mineral phases are laid down Pre-eruptive maturation phase-before eruption Post eruptive maturation and aging period  Dentine contains 4 times more than enamel  Fluoride concentration not uniform  Fluoride concentration –initial stages is higher than on completion ( mineralization process- release of F to the bathing fluid)  Primary teeth less fluoride concentration than permanent teeth
  23. 23.  Permanent teeth  Primary teeth  Non-fluoridated areas  Fluoridated areas  1100ppm  2200ppm  670ppm  950ppm
  24. 24.  F concentration in newly erupted teeth- higher in in incisal than cervical margin  Diffusion of F in enamel NaF and monoflurophosphate(100pmm)- 10-9cm2/sec  Speed at which F penetrates in enamel- 38 micrometer/ hour (186micrometer/ day)
  25. 25. Concentration in dentin:- more than enamel-apatite crystals are smaller -surface area and capacity to take is much larger In permanent teeth: Highest near the pulpal surface low in secondary dentin In primary teeth complicated –physiologic resorption occurs towards pulpal side greatest rise and fall – Pulpal surface of multirooted teeth
  26. 26. Fluoride concentration in Cementum:-  Higher than any skeleton or dental tissue  Tissue is very thin  Near the tissue surface- accessible to fluoride present in blood  Increases with age
  27. 27. Mechanism Of Action Of Fluoride In Caries Reduction.  Increased enamel resistance (or) reduction in enamel solubility  Increased rate of post eruptive maturation  Remineralization of incipient lesions  Interference with plaque microorganisms  Modification in tooth morphology
  28. 28. Enamel Fluorosis  Enamel mottling described by Eager in 1901 in Naples & Italy  Black and Mckay In 1916 in Colorodo and Arizona  Relationship between enamel mottling & excessive intake of fluoride in 1931 by Smith etal, Churchill JV, and Velu R etal  H. Trendley Dean and Arnold –Mottling : Concentration of fluoride in drinking water  Moderate to severely pitting and staining: pre-eruptively induced enamel porosity
  29. 29.  2 to 10 ppm- direct inhibitory effect on enzymatic function of Ameloblasts: resulting in defective matrix formation and subsequent hypominerlization  Hypocalcified enamel easily becomes hypoplastic after eruption due to abrasion and wear  No fluorosis- additional intake of F once crown formed and topical applications
  30. 30. CRITERIA FOR DIAGNOSIS OF ENAMEL FLUOROSIS Dean score Criteria 0 0.5 1.0 2.0 3.0 4.0 -Normal enamel -Questionable mottling: normal translucency is varied by a few white flecks or white spots. -very mild mottling: white opaque areas are scattered over the teeth; <25% -Mild mottling: not more than 50% -Moderate mottling: all enamel surfaces are effected Show marked wear; brownish stains are frequent
  31. 31. OSTEOFLUOROSIS  Common in workers of aluminum factory  Endemic fluorosis :India, China, South Africa  Fluoride dosage: 10 to 25 mg/day for a period of 10 to 20 years  Threshold level for osteofluorosis appears: 4000 to 6000 mg/kg of dry fat free bone  First stage: asymptomatic (radio graphically – increase density of vertebrae pelvis)  Advanced cases: bone density increased bone contours and trabeculae uneven and blurred extremities show thickening of compact bone irregular periosteal growth ( exostoses and osteophytes) increased in calcification in ligaments, tendons, and muscle insertion
  32. 32. At this stage complaints: vague pain in small joints. knee joints and joints of spine  Increased severity “crippling fluorosis”: stiffness of spine limitation of movements severe pain
  33. 33. SOFT TISSUE FLUOROSIS ARE WE NEGLECTING????  A team of Japanese professors found that children with mottled teeth have high incidence of heart damage than those without mottling (Tokushima J 1961)  Chronic exposure to F showed stomatitis and oral ulcer (Sheajjet etal 1967)  Optical neuritis and visual disturbance may result from direct effect of fluoride ion on neural tissue (Ellenhorn MJ 1988)
  34. 34.  Increased cases of reduced IQ, and mentally retarded pt. in endemic fluoride region (Xang et al 2003)  Pineal gland contains more fluoride than any other soft tissue in the body (Jennifer Luke,1997)  Chronic atrophic gastritis (Dasavathy et al 1996)  Decreased testosterone concentration (Susheela et al)  Damaged sperms, reduced sperm count and reduced fertility (Gosh et al 2002)
  35. 35. EXCRETION OF FLUORIDE 3 main avenues are urine, feces and perspiration Via kidneys:-  40 t0 50% of single dose excreted in urine during 24 hours  Factors influencing are  Previous exposure to fluoride  Age  Urinary flow  Urine PH  Kidney status  Glomerular filtration –tubular reabsorption in the form of HF-greater the acidic urine
  36. 36.  PH- < 5.6: Excreted fraction of filtered fluoride <5% Reobsorbtion-95%  Above 5.6: increased fraction of F excretion In acute poisoning: increased PH urine alkalizing agents enhance the elimination of F
  37. 37. Via the Gut:-  Undissolved and not absorbed excreted unchanged in feces  10% of total fluoride intake is excreted in feces Via sweat:-  Varying proportions of absorbed fluoride may lost from the body in perspiration  Under normal conditions of F intake-concentration of Fin sweating range of 0.07 to 0.5ppm
  38. 38. Via saliva:-  Less than 1% of absorbed from saliva was recovered from saliva  0.01 to 0.05ppm Via breast milk:-  0.01 to 0.05ppm  Selective in taking up fluoride- no evidence of transfer of F from plasma to milk  Cow’s milk higher F content than human milk
  39. 39. PLACENTAL TRANSFER OF FLUORIDE  Fluoride in primary teeth and bones: placental transfer  Placenta does not selectively inhibit fluoride transfer  Higher the fluoride ingestion: partial barrier may exist
  40. 40. Ingested fluoride Fecal excretion 5% 50% 45 % 0.01 to 0.1 ppm <½ of plasma F 0.067 – 0.5ppm
  41. 41. Fluoride supplementation Systemic Topical Dietary fluorides Salt fluoride Fluoride in sugar Water fluoridation School water fluoridation Milk fluoridation Professional application Self application
  42. 42. Water fluoridation Definitions:-  ‘Water fluoridation is defined as controlled adjustment of the concentration of fluoride in a communal water supply so as to maximum caries reduction and a clinically insignificant level of fluorosis.’  Defined as’ upward adjustment of the concentration of fluoride ion in a public water supply in such way that the concentration of fluoride in the water may be consistently maintained at 1 ppm by weight to prevent dental caries with minimum possibility of causing dental fluorosis’
  43. 43. • First began in Grand Rapids, U. S. A., in 1945 Studies on water fluoridation (city) Control 1. Grand Rapids (Michigan) 2. Newyork 3. Brantford (Ontario-Canada) 4. Evanston (Illinois) 5. Teil (Netherlands) Muskegon Kingston Sarnia Oak-Park Culemberg After 1o years -DMFT of fluoridated cities 60% lower than the control cities
  44. 44.  Murray and Rugg-gunn  compiled the status of water fluoridation globally  using over 90 studies he compared cariostatic benefits in primary and permanent dentition.  Early 1960’s successful water fluoridation program –in Singapore and Hongkong  Backer Dricks conformed caries protection….  Buccal, lingual and gingival smooth surface- 85%  Interproximal surface- 75%  Pit & fissure and occlusal surfaces- 35%  First study on deciduous dentition in UK by Weaver in North and South Sheilds (41%)
  45. 45.  Fluoride compounds used in water fluoridation-  Fluorospar  Sodium fluoride- most expensive source  Silicofluoride  Sodium silicofluoride- cheapest form  Hydrofluorosilicic acid  Amonium silicofluoride  Types of equipments for water fluoridation-  Saturation system- 4% NaF (recommended for small towns)  Dry feeder system-NaF or silicofluoride (medium sized towns)  Solution feeder- Hydrofluosilicic acid (large towns)
  46. 46. Optimal fluoride concentrations and climatic condition  In Temperate climates (formative stages) - 1ppm  Children living in this area- 1mg/daily  Galagan and Vermillion emperical formula: Based on daily fluid intake, body wt and temp ppm F =0.34/E E = -0.038+0.0062 t E -daily water intake in oz/lb of body wt t- max daily temp in degrees Fahrenheit WHO recommended (1994)- 0.5 to 1.0 ppm
  47. 47. • Simple modified method to determine opt fluoride concentration and mean annual temp… Richard etall oC oF Recommen ded ppm <18.3 18.9- 26.6 >26.7 <64.9 66.0-79.9 >80.1 1.1 - 1.3 0.8 - 1.0 0.5 - 0.7 In addition to climatic condition total fluoride intak other than water.. Reasonable goal 60 to 65% caries reduction without f
  48. 48. Benefits:-  Both pre eruptive and post eruptive effects  Topical effect through release in saliva  Least expensive and most effective  “Halo effect” or “Diffusion” Feasibility in INDIA  Ground water btw 1 and 5mg/ml.. (21mg/ml)  Ministry of Health Govt of India prescribed 1.0mg/ml and 2mg/ml  1983 Nanoti & 1988 Nawlakhe given Indian standard specification desirable limit as 0.6 – 1.2 mg/ml  Short coming- only implemented only in areas have central pipe water supply system.  Only 30% of population have piped water supply
  49. 49. School water fluoridation  Suitable alternative –b’cos f consumed during school days  4.5 to 6.3 ppm- no fluorosis  Caries reduction 45 to 50%  Venturi system is most suitable- almost no maintainance Advantages:-  Effective public health measure-water supply is not possible Disadvantages:-  5 to 6 years old upon starting school- will not provide preeruptive contact..  Intermittent fluoride exposure-less than 180 days in a year
  50. 50. Fluoride tablets Provides systemic effect before mineralization and topical effect after.. In deciduous dentition:-  Caries reduction 50 -80%, started before2 years continued of 3-4 years  Hoskova 1968(4 years) - fluoride tab started prenatally-93% - since birth- 54% In permanent dentition:-  20 to 40% caries reduction  Longest clinical trial carried out by Aasenden and Peebles-0.5mg F tab below 3years and 1mg thereafter—followed by 8-11 years  mean caries75 to 80% lower
  51. 51. • Fluoride level in surface enamel (1- 2micrometer) – Increased to 3000ppm – Fluoridated water- 2300ppm – Non fluoridated water- 1800ppm • 0.5mgF/day –upper limit desirable level first year of life • Concluding that fluoride supplements during developing dentitions results in caries reduction than water fluoridation Recommended dietary fluoride supplements (1999) Age in years Concentration of fluoride in drinking water ppm < 0.3ppm 0.3 to 0.6ppm >0.6ppm Birth to 6 years None None None 6 months-3 year 0.25mg/ day None None
  52. 52. Commercially available NaF (fluoraday, tymaflour and luride) – 2.2 mg NaF- 1mg of F – 1.1 mg NaF -0.5mg of F – 0.55 mg NaF – 0.25mg of F • Neuromuscular coordination not fully developed until 16- 18 weeks -up to 2 years drops are preferable • Daily recommended dose:- – Below 2 years – 0.5mg – 2 to 3 years -0.5 to 0.7mg – Above 3 years- 1 to 1.5mg Fluoride tablets: topical caries preventive agent to be used as Dental Public Health Measure in Rural India
  53. 53. To enhance cariostatic effect-  Chew and suck the tab  Preferably at bed time..  Continued at least until 12 to 14 years  Should not given –water supply exceed 0.7ppm  Should not given with milk and milk products  Cannot replace water fluoridation –parents fail to comply with the regimen
  54. 54. Salt fluoridation  Fluoridated salt in Switzerland for the first time in 1955 (90ppm)  90ppm -20 to 25% caries reduction  Optimum level of fluoride in salt –Toth suggested  Urinary fluoride excretion from salt should be similar to that obtained from fluoridated drinking water  200 to 350 ppm salt- 0.85 and 1.05 similar to populations ingested fluoridated water for 10 years.  250ppm did not achieve cariostatic effect – optimal fl content water
  55. 55. Advantages:-  Low cost  Negligible waste  Ease of implementation  Free choice for individual households Disadvantages:-  Fluoride dosages of different age in different regions  Lower salt consumption during tooth forming years
  56. 56. Feasibility in India:-  Viable and feasible method  Easily monitored  Effective control- supply  Individual monitoring not required  Freely available  Readily acceptable- does not alter the colour
  57. 57. Milk fluoridation  First mentioned by Ziegler in 1956  Stephen et al –daily ingestion of 200ml (7ppm) for 4 years, 38.8% reduction ( 1st permanent molar)  Hellestrom and Ericsson—fluoride uptake by enamel from salt is greater.. Advantages:-  Need to drink under 14 years of age Disadvantages:-  Incompletely ionized in milk  Lower absorption from milk than water  Variation in intake
  58. 58.  Requires parental or school efforts  Technical difficulties  Problem in distribution  High cost Feasibility in India:-  Binding with calcium and protein in milk  Not seem to viable and feasible  Cannot afford milk daily  No central milk supply system  Variation in intake and quantity of milk
  59. 59. Fluoridation of flour and sugar  Advantages requiring much less of chemical  Fluoridation of sugar has adv –combining the culprit and cure (difficulty to provide proper dosage)
  60. 60. Exception to school water fluoridation, salt fluoridation most promising alternative to water fluoridation. Method Average % caries reduction of dental caries Community water fluoridation School water fluoridation Dietary fluoride supplementation 50 to 65% 40% 50 to 65%
  61. 61. Fluoride toxicityToxic effects of fluorides: Acute and chronic Acute toxicity: – Accidental contamination of food by NaF and NaSiF salts Certainly Lethal Dose (CLD) 5 to 10 gm NaF or 32 to 64 mgF/kg Safely Tolerated dose (STD) ¼ CLD 1.25 to 2.5mg NaF or 8 to 16 mgF/kgTo prevent accidental poisoning of an infant weighing (10kg) Council on Dental Therapeutics of ADA recommended that: no more than 264 mg of NaF (120mg of F) dispensed at one time
  62. 62. Acute poisoning: – Causes death by blocking normal cellular metabolism – Inhibits enzymes causing vital functions- Initiation and transmission of nerve impulses to cease – Interferences with essential body functions controlled by calcium. Common signs and symptoms of acute fluoride toxicity: Low dosages High dosages Nausea Vomiting Hyper salivation Abdominal pain Diarrhea Convulsions Cardiac Arrhythmias Painful spasms Paresis
  63. 63.  Death usually results: cardiac failure or respiratory failure Serious symptoms : with in 1 to 2 hours after ingestion Death occurs from 2 to 4 hours after ingestion  Nausea and vomiting : dose 30 t0 80 mg of NaF  Vomiting diarrhea and severe abdominal pain: 100mg NaF  Gastrointestinal symptoms: corrosive effect on gastric mucosa by HF acid Treatment : administration of calcium or magnesium or aluminum salts
  64. 64. CHRONIC TOXICITY Fluoride level Water consumption Effects 0.7 to 1.2 ppm 1.5 to 3.0ppm 3.0 to 8.0ppm 8.0ppm or more Depending on temp of area Period of 5 to 10 years 15 to 20 years 5 to 10 years Prevents dental caries Mild dental fluorosis Severe dental fluorosis Mild skeletal fluorosis Severe form of dental skeletal fluorosis
  65. 65. DEFLUORIDATION • Defluoridation means to improve the quality of water with high fluoride concentration by adjusting the optimal level in drinking water – Absorption and ion exchange method:- exchange negative ions such OH- group for fluoride ions depends up on PH, temperature, flow rate, grain size of the material common used materials: activated alumina, activated bauxite, Zeolite, Tricalcium phosphate, activated bone char, magnesite, magnesite etc
  66. 66.  Precipitation method:- In a high PH condition, co-precipitation of several elements in water with fluoride ions forms fluoride salts- flocculation (Aluminum ions)  Alum  Alum and lime  Lime softening  Calcium chloride
  67. 67. Membrane separation • Reverse osmosis process • Expensive developing countries • 30% of raw water is lost in the process
  68. 68. INDIAN TECHNOLOGY FOR DEFLUORIDATION • Nalgonda Technique: India in 1975 most simple least expensive Easiest to operate
  69. 69. Fluoride water Supply Disinfection Filtration settlingFlocculation Alum NALGONDA TECHNIQUE
  70. 70. NALGONDA TECHNIQUE:- Advantages: – domestic and community levels – manually possible – cost effective – flexible design to use in different location
  71. 71. PRASHANTHI TECHNOLOGY • Activated Alumina- most popular cost effective Bio-Science, Department of Sathya Sai University of Higher Learning in Prasant Nilayam
  72. 72. OTHER METHODS TRIED IN INDIA • Fish bone charcoal- University of Roorkee • Drumstick Moringa cleifera- Reduce water turbidity -calcium and magnesium levels in plants • Askali- extract mycetial biomass-Osmania university Aspergillus riger • Clay materials-Montmosllonite KSF, Kaolin and a Silty Clay Sediment series • Tricalcium phosphate(TSP)
  73. 73. REFERENCES :- • Text book of pedodontics- SHOBA TANDON • Fluorides and Dental caries- AMRIT TEWARI • Pediatric dentistry- STEWART • Essentials of preventive and community dentistry- SHOBAN PETER • Pediatric dentistry: STEPHEN WEI • Fluorides in caries prevention- J.J. MURRAY