Role of fluoride in caries development

Question 1

How does ingested fluoride travel through the body?

Answer 1

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

Question 2

What is fluorides effect on enamel?

Answer 2

Decreases demineralisation, increases remineralisation, incorporated into developing enamel and interferes with metabolism of plaque bacteria (enolase)

Question 3

What is the critical pH?

Answer 3

5.5

Question 4

When fluoride is present is less calcium lost at a low pH?

Answer 4

Yes

Question 5

What does enamel require to remineralise?

Answer 5

Calcium and phosphate from saliva, dairy or CPP-ACP (tooth mousse)
Need a good saliva flow as well as good F- concentration

Question 6

What could we use to remineralise a subsurface lesion which has high fluoride?

Answer 6

Fluoride varnish or silver diamine fluoride

Question 7

How does fluoride interfere with bacterial metabolism?

Answer 7

Fluoride lowers bacterial cell pH to acidic conditions and interferes with glycolytic pathway before lactic acid is generated (enolase)

Question 8

Do you need to use fluoride every day to have an effect on caries?

Answer 8

Yes

Question 9

What is the concentration of varnish?

Answer 9

7000-22,600ppm

Question 10

What is the concentration of prescribed toothpaste?

Answer 10

5000pp

Question 11

What is the concentration of silver diamine fluoride?

Answer 11

40,000ppm

Question 12

what are sources of systemic fluoride?

Answer 12

Swallowed paste, water, foods - fish, tea, tablets, added in milk and salt

Question 13

What else does silver diamine fluoride do?

Answer 13

Desensitises

Question 14

What do you instruct a child and parent of up to 3 years?

Answer 14

1000ppm paste, smear, parents brush

Question 15

What do you instruct a child and parent of 3-6 years?

Answer 15

1350-1500ppm, pea sized, parents help up to 7

Question 16

What do you instruct someone who is at a low water fluoridated area?

Answer 16

Add daily F mouthwash

Question 17

What do you do with someone who is at high risk of caries?

Answer 17

Use varnishes and silver diamine fluoride

Question 18

What percentages do F mouthwashes come in?

Answer 18

0.05% daily or 0.2% weekly - patient may be more compliant with weekly, consider age and does it have alcohol

Question 19

What topical fluorides are available?

Answer 19

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)

Question 20

What restorations can you use to protect someone against caries?

Answer 20

GIC
Compomers
Fissure sealants
Resin composites

Question 21

What is fluorosis and its causes?

Answer 21

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

Question 22

Who is at high risk of fluorosis and why?

Answer 22

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.

Question 23

How does fluoride become lethal?

Answer 23

Can affect calcium metabolism and cardiac system

Question 24

What to consider in relation to fluoride?

Answer 24

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

Question 25

What does fluoride do?

Answer 25

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)