Fluoride mechanism Flashcards
What are the mechanisms of fluoride on teeth?
- Promotes remineralization with calcium and phosphate ions: when flouride is incoporated into remineralising enamel, it forms fluoroapatite
- Reducing demineralization. Fluorapatite is more acid resistant than hydroxyapatite
- It is antimicrobial. Stops glycolytic pathway which stops bacteria from producing acid = organism dies
- Fluoride interferes with carbohydrate metabolism in bacteria, thus reducing the accumulation of intracellular and extracellular polysaccharides (i.e. plaque)
What are the 6 ways in which fluoride can be delivered?
Water fluoridation
Tablets
Toothpaste
Rinse
Gel
Varnish
Describe caries prevention via water fluoridation.
- Amount depends on how much water people drink. Lower water consumption = the need for more fluoride
- This produces a topical effect. FL is incorporated as fluoroapatite
Describe caries prevention via tablets
- Previously believed that ingesting fluoride reduced caries incidence by forming fluoroapatite
- However now we know that fluoride acts topically to remineralise enamel
- There is a risk of fluorosis from fluoride tablet ingestion
Describe caries prevention via toothpaste
- Added as sodium fluoride (NaF), sodium monofluorophosphate (MFP), stannous or amine fluoride
- 25% reduction in the prevalence of caries in developed countries
- 0-18 months child: no toothpaste, supervised cleaning
- 18 months-5 years olds: 440-550ppm FL
- > 5 years old: 1000 ppm FL
• For Preschool children, advise swishing and pumping between teeth
If no water fluoridation, start at younger age (from 1 year, advise 400-500 ppm). Pea-sized amount, soft toothbrush, clean twice a day and spit out, not swallow and not rinse
Describe caries prevention via fluroide rinse
- Weekly or fortnightly rinses: 0.2% (900-910 ppm F) NaF and
- Daily rinses: 0.05% (220-227 ppm F)
NaF rinses are ideal Indications for: • undergoing orthodontic treatment • Post radiation hyposalivation • Unable to perform adequate toothbrushing • High risk of dental caries
Describe caries prevention via gel
- More effective in permanent dentition
- According to ARCPOH guideline fluoride gels and foams (>1.5 mg/g F, 1500 ppm F) may be used for 10 years or more at a high risk situations
- Fluoride gel is applied topically in a tray
- It is important to ensure that patients do not swallow the gel during application
• APF gel: 12300 ppm F (1.23%) consists of NaF, hydrofluoric acid and orthophosphoric acid
• NEUTRAL NaF gel: 2%, 9000 ppm F, used for enamel erosion, exposed dentine, carious dentine, hypomineralization, preferred where restorations of GI cement, composite resin or porcelain
Stannous fluoride gel (0.4%): used for remineralization of white spot and hypomineralized enamel, root caries. Stannous ion may cause discoloration of teeth stain margins of fillings
Describe caries prevention via varnish
- Duraphat: 22,600ppm FL (22.6%)
- Primary dentition: 6 mg F
- Mixed dentition: 9 mg F
- Only used for high risk caries, including children under age 10 years
• Tip: Dry teeth for adhesion and better fluoride uptake
MI Varnish: contains high levels of fluoride and CPP-ACP
Explain fluoride’s toxicity
- Too much fluoride = fluorosis
- Also, fluoride can be toxic in certain cirumstances
- Probable toxic dose: 32-60 mg F/kg of body weight
List signs and symptoms of fluoride toxicity
- Nausea, epigastric distress, often vomiting
- Excessive salivation, tear production, mucous discharge from nose and mouth and sweating
- Headache
- Diarrhoea and generalized weakness
• On lethal dose: convulsions, hypotension, hypocalcaemia and hyper kalaemia, respiratory acidosis, unconsciousness
What are the risks of usinf fluoride products?
- Discolouration from stannous fluoride
- Fluorosis from excessive ingested fluoride
- If ingesting fluoride; its toxicity
- CCP-ACP/ MI fluoride varnish: not for milk protein allergy
What are the potential uses of CPP- ACP?
- CPP-ACP is marketed as Recaldent
- The product Tooth Moose contains Recaldent (containing 1.2% CPP-ACP) is the trade name
- CPP-ACP incorporated in a chewing gum (at 3%) was tested in a randomised controlled trial in Melbourne and proved to be a caries preventive agent
- CPP- ACFP; released FL, calcium and phosphate
- However, as tested in the vehicle “Tooth Mousse”, it has failed to live up to expectations
