Fluorides Flashcards
What are the different sources of fluoride?
Diet (fis, offal and tea)
Water
Medicinal (over the counter and prescribed)
What are the benefits of water fluoridation?
1ppm has best max effects and benefits of fluoride with minimum amount of mottling
= 50% reduction in caries (esp. interproximal and smooth surface) but also a 30% reduction in pits and fissures
What is it key to remember about the best level of water fluoridation?>
1ppm eas set before fluoride containing products were so readily available therefore now a lower dose may be better
How does fluoride work?
Decreases rates of demineralisation (mainly topically), creates fluorapatite crystals (more resistant to acid erosion), some effect on bacteria
What is the critical pH?
5.5 (remineralisation) - 3.5 (demineralisation)
What is the appearance of mild fluorosis?
Diffuse flecks/patches
What is the appearance of moderate fluorosis?
mottling, striations, yellow/brown
What is the appearance of severe fluorosis?
appearance of enamel hypoplasia
What happens with too much fluoride?
- blocks cell metabolism
- interferes with calcium metabolism
- affects nerve impulses and conduction
What is acute overdose?
Fluorosis
What are the signs and symptoms of fluoride overdose?
- Vomiting, nausea, and diarrhoea
- Excessive salivation, tears, mucus and sweat
- Headache
- Generalised weakness
What dose causes lethal poisoning?
32-64 mg F/kg body weight (n.b. there have been some cases of death at 16 mg F/kg body weight)
When are you more likely to have a overdose of fluoride?
With a high dose bolus or repeated low levels
What is 1000ppm in mg F/g?
1mg F/g
What is 400ppm in mg F/g?
0.4mg F/g
What are the consequences of a toxic dose?
GI upset at approx 1mg F/kg body weight
How to deal with a fluoride overdose?
- get clear history, check dose of fluoride (package)
- Support vital signs
- management depends on dose
- drink as much milk/ milk of magnesia as possible (absorbs remaining fluoride in stomach)
How does fluorosis occur?
- affects enamel maturation (impairs mineral acquisition)
- greatest risk for centra 1’s is 15-30 months
- corral development complete at 6 y/o = less of an issue
What are the maximum doses for a 2 y/o (10kg)?
Fluoride drops = 3 ml 1mg tablets = x10 mouth rinse 0.05% = 43ml mouth rinse 0.2% = 11ml duraphat varnish = 0.43ml
What are the maximum doses for a 5 y/o (20kg)?
Fluoride drops = 5 ml 1mg tablets = x20 mouth rinse 0.05% = 86ml mouth rinse 0.2% = 22ml duraphat varnish = 0.86ml
What are the maximum doses for a 10 y/o (30kg)?
Fluoride drops = 8 ml 1mg tablets = x30 mouth rinse 0.05% = 130ml mouth rinse 0.2% = 33ml duraphat varnish = 1.3ml
What properties of the fluoride containing agents make a child more likely to overdose?
Nice colour and liquid if not secure
What do we do in the BDH for all children?
- Diet diary (sugar reducing advice)
- plaque control
- Fluoride sources (local water and provision of additional fluoride)
- Pit and fissure sealants for first permanent molars
- 2X daily toothbrushing before bed and 1 other time, supervised
What ppm fluoride toothpaste should 0-3 y/o use?
1000 ppm F toothpaste
= smear 2 x daily
What ppm fluoride toothpaste should 3+ use?
1350-1500 ppm F toothpaste
= pea sized amount 2 x daily
What % fluoride mouthwash should 6+ use? and how often should they use it?
NaF 0.05% 10ml daily
NaF 0.2% 10ml weekly
When should a fluoride mouthwash be used?
Anytime between morning brush and evening brush i.e. when home from school
How many times a year do we apply duraphat varnish to children teeth?
2x a year
What ppm toothpaste is used by all high caries risk children?
1350-1500ppm
What fluoride measures do all high caries risk children get?
Higher fluoride toothpaste AND Duraphat more frequently AND fluoride mouthwash/higher fluoride toothpaste prescribed
How often is duraphat applied in high caries risk children?
3-4 x yearly
What ppm toothpaste is prescribed for >10y/o if fluoride mouthwash is inappropriate?
2800 ppm (0.619% NaF)
What ppm toothpaste is prescribed for 16y/o + if fluoride mouthwash is inappropriate?
5000 ppm (1.1% NaF)
What are the different forms of fluorides?
Toothpaste, gel, mouthwash, varnish, drops, tablets, glass beads and foam
How do we decide which form of fluoride to give?
Tailored for each patient
What is 1500 ppm toothpaste equivalent to in % NaF and Na mfp?
- 32% NaF
1. 14% Na mfp
What is 1000 ppm toothpaste equivalent to in % NaF and Na mfp?
- 22% NaF
0. 76% Na mfp
What is 500 ppm toothpaste equivalent to in % NaF and Na mfp?
- 11% NaF
0. 38% Na mfp
Why can toothpaste labels be misleading?
Can show fluoride level in ppm, % NaF or % Na mfp
What is the lowest dose that is effective at preventing caries?
1000ppm
What substance in fluoride varnishes can people be allergic to?
Colophony = tree resin
What is the evidence for using fluoride varnishes 2 x a year?
decrease in DMFT by 46% and dmft by 33%
Which conditions should you not use fluoride varnish with?
Ulcerative gingivitis, stomatitis or history of allergy (hospitalisation for asthma)
What is the maximum exposure to fluoride varnishes?
every 3 months
What are the different brand names for fluoride varnish?
Duraphat or vocopaste
What concentration is fluoride varnish?
50mg/ml = 5% NaF = 22600 ppm F
When applying fluoride varnish what should have been done to the teeth?
Dry
What have fluoride varnishes been shown to do?
Reverse carious lesions
For how long after fluoride varnish has been applied should you refrain from food and drink for?
30 mins
What concentration fluoride drops should be used for 6 months - 3 years?
500mcg/0.15ml
How frequently should fluoride drops be used?
7 x daily
What dose and quantity of fluoride tablet should be given to 6 months- 3yrs?
1/2 1.1 mg NaF tablet daily = 0.25 mg F
What dose and quantity of fluoride tablet should be given to 3-6 y/o?
1.1 mg NaF tablet daily = 0.5 mg F
What dose and quantity of fluoride tablet should be given to 6y/o +?
2 x 1.1mg NaF tablet daily = 1 mg F
In which instances should we halve the doses of fluoride tablets?
If they live in an area where water us 0.3-0.7 ppm
When should fluoride tablets not be used?
If they live in an area where water >0.7ppm
What are the main issues with fluoride tablets and drops?
Compliance and easy to overdose
What is the evidence for fluoride supplements?
Decreases caries, effect is unclear on primary teeth and overall evidence is week
How do glass beads work?
V. small encapsulated beads placed subgingivally = slowly release the contained fluoride
At what age is there an increased risk of fluorosis and why?
How do we identify the children in need of fluoride?
Risk based assessment
What strategies do we combine fluoride with?
Diet, radiographs, fissure sealants, oral hygiene, prevention of s. mutans and CPP-ACP = helps remineralise teeth
What can we do to fix the aesthetic consequences of fluorosis?
Vital bleach to remove dark staining, mask white areas with composite build ups
How do we manage an overdose of fluoride
Milk + absorb for 4 hours
How do we manage an overdose of fluoride 5-15 mg/kg?
send to emergency department, observe and support vital signs and give milk, gastric lavage (stomach pump)
How do we manage an overdose of fluoride > 15 mg/kg?
Send to emergency department immediately, give IV calcium gluconate, activated charcoal 1g/kg (max 50g) every 4 hours and gastric lavage, life support and cardiac monitoring
How can we prevent fluorosis and overdose?
- Good history taking
- examine package carefully
- aim for topical not systemic
- avoid critical age (0-6y/o)
- good education for parents/carers
- prescribe max 120 mg supplements at any one time
