Role of fluoride in caries development Flashcards
How does ingested fluoride travel through the body?
Systemic absorption mainly through stomach occurs very quickly.
F- absorbed across HF into the bloodstream
F- enters saliva via blood stream
Incorporated into calcifying tissues - bone, teeth
Excretion is mainly through kidney
What is fluorides effect on enamel?
Decreases demineralisation, increases remineralisation, incorporated into developing enamel and interferes with metabolism of plaque bacteria (enolase)
What is the critical pH?
5.5
When fluoride is present is less calcium lost at a low pH?
Yes
What does enamel require to remineralise?
Calcium and phosphate from saliva, dairy or CPP-ACP (tooth mousse)
Need a good saliva flow as well as good F- concentration
What could we use to remineralise a subsurface lesion which has high fluoride?
Fluoride varnish or silver diamine fluoride
How does fluoride interfere with bacterial metabolism?
Fluoride lowers bacterial cell pH to acidic conditions and interferes with glycolytic pathway before lactic acid is generated (enolase)
Do you need to use fluoride every day to have an effect on caries?
Yes
What is the concentration of varnish?
7000-22,600ppm
What is the concentration of prescribed toothpaste?
5000pp
What is the concentration of silver diamine fluoride?
40,000ppm
what are sources of systemic fluoride?
Swallowed paste, water, foods - fish, tea, tablets, added in milk and salt
What else does silver diamine fluoride do?
Desensitises
What do you instruct a child and parent of up to 3 years?
1000ppm paste, smear, parents brush
What do you instruct a child and parent of 3-6 years?
1350-1500ppm, pea sized, parents help up to 7
What do you instruct someone who is at a low water fluoridated area?
Add daily F mouthwash
What do you do with someone who is at high risk of caries?
Use varnishes and silver diamine fluoride
What percentages do F mouthwashes come in?
0.05% daily or 0.2% weekly - patient may be more compliant with weekly, consider age and does it have alcohol
What topical fluorides are available?
ClinPro white varnish preferred (3-6 months depending on risk)
Fluoride prophylaxis paste
Varnish (colophony free if asthmatic)
Silver diamine (38% reduction if done 2x a year)
What restorations can you use to protect someone against caries?
GIC
Compomers
Fissure sealants
Resin composites
What is fluorosis and its causes?
Occurs when more than trace amounts ingested in tooth development by swallowing toothpaste or water with naturally high levels.
Enamel has a higher protein content, high levels of fluoride prevent removal of protein matrix during maturation.
Results in chalky looking enamel with streaks - hypomineralised.
Teeth formed at same time will have a similar appearance
Who is at high risk of fluorosis and why?
18 months - 3 years on permanent anteriors
Children cannot spit properly before 3-4 - avoid systemic fluorides until then, smear of toothpaste at 3, pea sized 3-6.
Parents should not share high F toothpaste and have child safe caps.
How does fluoride become lethal?
Can affect calcium metabolism and cardiac system
What to consider in relation to fluoride?
Caries risk Age Sufficient calcium and phosphate in saliva Oral hygiene Dental materials in mouth - porcelain can have no acidic fluorides What can patient manage Cost Safety considerations
What does fluoride do?
Prevents caries by forming CaF on the tooth surface and desensitisation of hypersensitive teeth - forming calcium fluoride globules which occlude dentinal tubules (2-3 applications within a few days)
