Caries and Fluoride Flashcards
Factors which influence caries risk
- Previous caries exposure
- Dietary habits
- Plaque control
- Medical history
- sources of fluoride
- Tooth structure (local/general)
- Social history
- Saliva
- Wearing an intra-oral appliance
Sources of fluoride
Water - added or natural
Diet - fish, offal, tea
Toothpaste
Prescribed - mouthwash, tablets, gels, toothpaste
Ideal amount of water fluoridation
1ppm
Results in 50% overall reduction in causes, particular interproximal and smooth surface. 30% in pits and fissures
How does fluoride work
Reduces the rate of demineralisation. Creates fluoroapetite crystals which reduce the critical pH from 5.5 to 3.5
low concentrations of fluoride in saliva creates fluorapatite crystals which reduce the crticial pH from 5.5 to 3.3 and thus more resistant to acid dissolution. it also has an affect on bacteria where it leads to inhibition of the enolase enzyme which is imoortant in glycolysis
0.32 % Sodium fluoride = how Na mfp/ ppm F
1.14% and 1500 ppm
0.22% Sodium fluoride = how Na mfp/ ppm F
0.76% and 1000 ppm
0.11% Sodium fluoride = how Na mfp/ ppm F
0.38% and 500 ppm
The benefit of using fluoride toothpaste is shown only at…
1000 ppm and higher
marhino et al 2003
What is duraphat varnish
5% sodium fluoride, 22600 ppm fluoride, 50mg/ml
Has to be applied professionally and must refrain from eating and drinking for at least 30 mins
When do you not give duraphat toothpaste
Ulcerative gingivitis
stomatitis
history of admission to hospital because of allergy, including asthma
Fluoride that children 0-3 should be using
1000ppm fluoride toothpaste, use a smear twice daily
Fluoride that children 3+ should be using
1350-1500ppm. Fluoride toothpaste, use a pea-sized amount twice daily PLUS duraphat twice yearly
High caries risk children
All should use 1350-1500ppm toothpaste and duraphat varnish 3-4 yearly
Sodium fluoride mouthwash for ages 6+
Sodium fluoride mouthwash 0.05%, 10 ml daily
Sodium fluoride mouthwash 0.2%, 10ml weekly
Prescribing duraphat toothpaste
10+ years - 2800ppm, 0.619% NaF
16+ years - 5000ppm, 1.1% NaF
Dose of fluoride that causes GI upset
approx 1mg F/kg body weight
Lethal poisoning of fluoride
32-64 mg F/kg body weight
What does too much fluoride do?
- Blocks cell metabolism
- Interference with calcium metabolism
- nerve-impulse and conduction
Signs and symptoms of overdose
Nausea, vomiting, diarrhoea, excess salivation/tears/mucous/sweat, headache, generalised weakness
What is the level of fluoride in bristol water?
0.1-0.3ppm
What range of fluoride is needed in saliva to prevent caries?
0.02-0.04
below 0.02: caries susceptible
above 0.04: non caries susceptible
How does fluoride block the enzyme enolase?
below pH 5.0 fluorde becomes hydrofluoric acid
At what level is fluoride in toothpaste effective? Reference?
Marinho 2003
1000ppm and higher
When is the risk for fluorisis highest?
below 12/12
Marinho 2003
What evidence is there supporting the effect of fluoride on caries in permanent vs deciduous teeth?
reference?
Permanent: reduction in caries seen when supplements given
Primary: effect not clear
Tubert 2011
How effective is fluoride varnish in permanent vs primary teeth? reference?
Adult: 46% reduction
Primary teeth: 33%
Marinho 2002
How do you deal with fluoride overdose?
Clear history
try to establish the amount of fluoride ingested
give as much milk/milk of magnesia as possible
How do you manage an excess of 5mg/kg fluroide?
Give milk and observe for 4 hours
How do you manage an overdose of 5-15mg/kg?
gastric lavage, ED
How do you manage an overdose of more than 15mg/kg?
send to ED, calcium gluconate IV, activated charcoal 1g/kg, gastric lavage, life support and cardiac monitoring
How does fluorosis occur?
Fluoride effects mineral acquisition, and it is more likely to occur after high bolus or repeated low level
When are the centrals at greatest risk of fluorisis?
15-30 months
How can fluorosis be classified?
mild : few specks
moderate : mottling
severe: enamel hypoplasia
How can you prevent fluoride overdose?
Aim for topical rather than systemic
Avoid critical age 0-6
prescribe a maximum of 120mg at any one time
How does CPP-ACP work?
stabilises Ca and Phsophate ions via phosphrylated serine groups creating supersaturated silutions of these ions
How long does CPP-ACP last?
3 hours
