Fluoride Flashcards
Give some basic chemistry on fluoride
- Fluoride is the ion of fluorine
- When fluorine binds to another element, it becomes a negative charged ion
- e.g. sodium fluoride, sodium flurosilicate
What are sources of fluoride in day-day life?
Fish Meat Eggs Tea leaves Mouthwash Gels Toothpaste Water fluoridation
Why was fluoride recognised to help oral health?
Brown stains formed on teeth during enamel formation was due to drinking groundwater. These people had lower caries incidence.
It was found that fluoride levels up tp 1.0ppm did not cause fluorosis.
Explain the difference between HA and fluroHA
HA = mineral in enamel that can be dissolved in acidic conditions. Ions lost can be replaced by those in saliva, caries forms if replacement rate is lower than rate of loss.
FluroHA = fluoride ions replace HA ions. This structure is stronger and more resistant to acidic conditions. This reduces caries formation rate.
What are the two ways that fluoride is incorporated in the oral cavity?
Pre-eruptive (systemic)
Post-eruptive (topical)
Explain how fluoride works pre-eruptively?
Can be incorporated in 3 ways:
- main crystal structure
- surface level of crystal
- present in enamel fluid
This then causes an increase in crystal size and decrease in acid solubility.
Fluoride release from the structure triggers remineralisation.
How does fluoride help post-eruptive?
- Demin prevention (due to formation of fluroHA)
- Remin promotion (mineral released creates a super-saturated environment)
- Decreases acid production by inhibiting glycolysis in cariogenic bacteria
- Inhibits production of extracellular polysaccharides by cariogenic bacteria (reduces plaque adherence)
- Bactericidal action on cariogenic bacteria in plaque
What are the two levels that fluoride application can be used?
- Community Level (Water fluoridation, salt, milk)
- Individual Level (self applied mouthrinses/toothpaste/diet or professionally applied varnishes)
What is the mechansim of water fluoridation?
Systemic method of fluoride delivery.
Action mechanism is mainly topical:
- remin of demineralised enamel depending on frequency of contact of fluoride water with tooth surface
- pre-eruptive effect especially in fissure surfaces of permanent 1st molars
Give some facts on water fluoridation
- Applied to water as hydroflusilcic acid, sodium silicofluoride and sodium fluoride
- Max permitted level in water is 1.5mg
- Optimal level is 0.7ppm
- Local authority decision
- Most cost effective supply of fluoride
Apart from water, what 2 other dietary ways can fluoride be supplied?
Salt
- KF or NaF
- worked as well as water
- based on a high consumption of salt a day
- could be promoting higher salt intake
Milk
- Added to milk for children
- high conc
- not all fluoride can be released as it is not completely ionised
- post-eruptive effect is limited
How does the fluoride from toothpastes work?
Topical action in demineralised enamel.
Reservoir of fluoride in plaque is available for remineralisation when pH drops.
Fluoride concentrations in plaque can be increased for several hours after exposure to a fluoridated toothpaste (increases with acid release).
Most evidence to suggest this works.
Give some details on fluoride mouthwashes
- Good for high caries risk patients
- Added as NaF, ammonium fluoride
- Daily or weekly rinses
- Can reduce beneficial effects of fluoride toothpaste if used after it
Give some details on fluoride varnishes
Remineralisation mechanism - precipitates on enamel surface giving a reservoir of F ions
However - can be time consuming and had to access service
Used in conjunction with toothpaste = best effect
How does toothpaste advice change from children to adults?
Children use a smear of toothpaste where as adults use pea-sized.
Children should focus on reducing sugary foods.
