Which of these mechanisms allow fluoride to increase the resistance of teeth to acid attack?
Reduce/inhibit enamel dissolving
Promoting remineralisation
Changing plaque ecology
Reducing plaque acid production
Increased enamel dissolution
What is the acute lethal dose of fluoride?
32-64mg F / kg body weight
5 g F / kg body weight
32-64g F / kg body weight
5 mg F / kg body weight
What is the toxic dose for fluoride?
5 mg F/ kg body weight
5 g F/ kg body weight
What are some clinical symptoms of fluoride poisoning?
Nausea
Diarrhoea
Convulsions
Cardiac arrhythmias
Conjunctivitis
Why might acute fluoride poisoning lead to cardiac dysrhythymia?
Hypocalcemia / Hyperkalemia
Hypercalcemia / Hypokalemia
Hypernatremia / Hyperkalemia
Hypercalcemia / Hyponatremia
Skeletal fluorosis is sometimes mistaken for...
Arthritis
Osteoporosis
Parkinson's
Huntington's
How does fluoride impair enamel formation?
Interferes with the ameloblasts in the early maturation phase leading to imperfect crystals / prisms
Interferes with the ameloblasts in the late maturation phase leading to imperfect crystals / prisms
Leads to imperfect collagen deposition by the ameloblasts leading to imperfect crystals / prisms
Leads to imperfect hydroxyapatite deposition by the odontoblasts leading to imperfect enamel crystals / prisms
How does fluoride impair dentin formation?
Leads to impaired random collagen and hydroxyapatite deposition which is more susceptible to caries
Leads to impaired random hydroxyapatite deposition which is more susceptible to caries
Leads to impaired random collagen deposition which is more susceptible to caries
Fluoride _________ mineralisation of bone, leading to heavy irregular mineralisation of bone.
Stimulates
Inhibits
75-90% of fluoride is absorbed in the
Stomach
Duodenum and Upper jejunum
Lower jejunum and ileum
Duodenum only
Fluoride is mostly absorbed by...
Passive diffusion
Active transport
Facilitated diffusion
Maternal and Foetal blood fluoride levels tend to be..
Similar, therefore related.
Completely different, therefore unrelated.
The three phases of fluoride transport are:
1. Tissue fluid / soft tissue eq and dilution 2. Hard tissue deposition in tissues with high F 3. clearance of F which not deposited in skeleton
Fluoride accumulates in the soft tissues.
Saliva and Tissue fluid have similar fluoride levels to blood plasma.
Why does fluoride have such a high affinity for bone?
It has a high affinity for hydroxyapatite in bone, preferentially forming fluorapatite.
It has a high affinity for collagen in bone, preferentially forming fluoridated collagen.
It has a high affinity for receptors in bone marrow which allow it to bind readily
What is the half life of fluoride in someone who is not frequently exposed to F?
24 hrs
2 years
12 hrs
1 hr
What factors might impact on renal clearance of fluoride?
Dose of fluoride
Previous exposure
Fluid intake
Cirrhosis
Half life of fluoride
Fluoride interferes with acid production by bacteria. How does it inhibit it?
Inhibits the enolase enzyme involved in glycolysis (which ultimately produces lactic acid)
Inhibits the alpha-ketoglutarate enzyme involved in glycolysis (which ultimately produces lactic acid)
Inhibits the hexokinase enzyme involved in glycolysis (which ultimately produces lactic acid)
Fluoride interferes with extracellular polysaccharide formation
Fluoride decreases bacterial intracellular polysaccharide formation and glucose uptake.
Fluoride does not affect cariogenicity but does decrease the amount of plaque formation.
