fluorides

fluorine trace elementnot found in free elemental form in nature

fluoridefound everywhere throughout naturewater is the major source of ingested fluoride- deep artesian wellfound in soils rich in fluospar ( calcium fluoride), cryolite (sodium aluminum fluoride)found in other minerals: fluorapatite, fluorcarbonates, fluorphophatates, fluorsilicates

fluoridealso found in plants, foodstuffs and body tissuesin calcified structures: teeth & skeleton

fluorideabsorptionmajor site = stomachthere is also intestinal absorptionsoluble fluoride in drinking water is almost absorbed50-80% of fluoride from the foods

fluoride distributionteethskeletonextracellular fluidsintracellular fluidssaliva

fluoridedistributionteeth & skeleton - highest concentrationaffinity to calciumteeth- cementum, bone, dentin, enamel ( descending order)increases rapidly- early mineralization periodincreases at a slower rate with age

fluoride distribution0.01 ppm in the salivawhen ingested, the salivary fluoride level increases, beginning after 5-15 minsreaches a maximum after about 30 minsdecreases to normal levels in about 1 h

fluoride excretionmajor route of excretion is the urine (90-95%)5-10% found in the fecessweat- minute amount

fluorideexcretionthe rapidity of the excretion of fluoride & high affinity of the calcified structureseffective mechanisms for maintaining low concentrations of fluoride in the soft tissue plasma

fluoride excretionthe amount of urinary excretion is directly related to the degree of active bone growthgrowing child = active laying down of bone matrix= diminished fluoride excretionadults with mature bones and fully mineralized teeth = fluoride excretion

fluoridestoragecalcified structuresbone & teeth during active stage of mineralization

fluoride storageskeletons of older people contain more fluoride than those of younger onesfluoride in bone gradually increases with agerate and amount of fluoride deposition is greatest during the active growth years

factors that attract fluoride to bonespresence of an active growth area at the ends of the long bonessmall size of the bone crystalsclose contact that bone has with the blood supply

fluoridestoragefluoride is deposited in the enamel via the systemic route during the developmental and maturation stages of enamel formationadult enamel- fluoride penetrates from the oral environment via diffusionremineralized cariousdentin contain more fluoride than enamelchemically similar to boneadjacent to pulp -highest concentration

fluoride toxicitysafe- 1 to 8 ppm dailywhen ingested in excessive amounts over a long period of time, fluoride can be toxicexcessive mineralization of ligaments & bonesacute toxicity or death - from ingestion of a single dose of 2.5 to 5.0 grams of NaF

fluoridedietary sourcesall food contain at least traces of fluoridewaterborne fluorides- constitutes the most important source for manfluoridated beveragesoptimal levels- 1ppmfluorosis ( mottled enamel)- 2ppm

fluoridedietary sourcessmall amounts of fluoridemeats, fruits, vegetables, & cerealsrich sourcestea- leaves( 75-100ppm)seafood especially fish with small bonessardines & salmon

fluoride &mottled enamelMottled Enamelclinical characteristicswhite and/or brown spotty staining of the tooth enamel surfaceshorizontal striations or pits

fluoride &mottled enamelhistological appearancedeficient in number of ameloblasts, which affects enamel matrix formation which causes pitting ( enamel hypoplasia)deficient in mineral deposits accompanied by poorly formed interprismatic rod substance, which causes chalkiness ( enamel hypocalcification)

fluoride & mottled enameloccur in the formative stages when metabolism of ameloblasts can be interfered with.exposure to high concentrations of fluoride- 2 ppm or more

fluorides &dental cariescommunal water fluoridationschool water fluoridationdietary supplements of fluoride tabletsprenatal fluoride supplements

fluoride acquisitionby the toothendogenous or systemic fluoride uptakeexogenous or topical fluoride

systemic fluorideuptake of fluoride by the tooth via the pulp and other source of blood supplyenamel is still mineralizingsalivary fluoride leveltopical effects- post-eruptive period

topical fluoridedentrifices or toothpastesfluoride pastes/ gel or rinseNa F, Acidulated Phosphate flouridemaintained high level of salivary fluorideeating & drinking might speed up the clearance of fluoride from the mouth

mechanisms of anti caries action of fluoridean increase in enamel resistance to acid solubilityresults from high concentration of fluoride in the outer enamel surfaceprevents or retards acid demineralizationhas more crystals - fluorapatite- less soluble in acid

fluoride mechanisms of anti caries action

the ability of fluoride to remineralize demineralized or hypomineralized enamelinterval between meals, there is a reprecipitation of minerals, or remineralizationavailability of fluoride

fluoridemechanisms of anti caries action

fluorides anti-bacterial effects when given in high concentrations in a topical or local vehicleinhibit many enzymes essential to cell metabolism & growth of bacteria