The role of fluoride in caries prevention Flashcards
What is ‘upstream’ prevention?
- What we do at a population level
What is ‘downstream’ prevention?
What we do at an individual level
What are community examples of fluoride therapy? (3)
- Water
- School based brushing
- Varnish (possibly SDF)
What are clinic examples of fluoride therapy? (3)
- Varnish (possibly SDF)
- Gels & foams
- Slow release
What are at home examples of fluoride therapy? (3)
- Toothpaste
- Mouthwash
- Tablets
Hoe does fluoride prevent caries? (6)
- Fluoride present in fluid at the plaque/tooth interface promotes remineralisation
- The fluoro-apatite formed is less susceptible to demineralisation
- Topical effect greater than synthetic effect
- Fluoride may also have an effect on bacteria and metabolic pathways resulting in less acid being produced
- Maintain elevated oral levels of fluoride for as long as possible (little and often)
- Fluoride most effective on early lesion
What type of effect of fluoride is more effective: topical or systemic?
- Topical effect is greater
Which type of lesion is fluoride most effective on?
- Early lesions
Is the oral reservoir for fluoride large or small?
- Small
What is a negative of fluoride in toothpaste in relation to the oral reservoir?
- The fluoride from toothpaste disappears quickly
What are the 2 broad types of fluoride in oral reservoirs?
- Mineral deposits (CaF2 in saliva and fluid phase of plaque)
- Biologically/bacterially bound calcium-fluoride
The aim in prevention is to maintain cariostatic levels of fluoride in oral fluids. IS this correct?
Yes
What are the predominant methods of delivering fluoride in oral care products? (4)
- Toothpaste
- Mouth rinses
- Varnishes and gels
- Tablets
What is the general level of fluoride in a community water supply?
- 0.8-1.0ppm
Does Scotland have water fluoridation?
- No
If fluoride action is topical, is water fluoridation relevant ?
- Simple - when you ingest the water and the fluoride in that water it does become incorporated into saliva so saliva will contain very low and frequent concentrations of fluoride
How are fluoride tablets most effective?
- Using the ‘swish and ‘swallow’ procedure - linking to the topical effect rather than the systemic effect
What is the dosage of fluoride tablets for 6m-3YO?
0.25mg
What is the dosage of fluoride tablets for 3-6yrs?
0.5mg
What is the dosage of fluoride tablets for >6yrs?
1.0mg
Are fluoride tablets are topical or systemic method of delivery?
- Systemic
What is the risk-benefit balance like for fluoride tablets?
- Poor risk-benefit balance
Fluoride mouthrinses are commonly available for home use. What are the 2 concentrations available?
- Daily (0.05% 227ppmF)
- Weekly (0.2% 909ppmF)
By what % do fluoride mouthrinses reduce caries?
- By around 30%
What is more effective: daily rinsing or weekly rinsing with fluoride mouthrinses?
- Daily rinsing slightly more effective but more expensive
What is important for efficacy of fluoride mouthrinses?
- Swishing around the mouth
Do fluoride mouthrinses have a good or bad benefit to risk ratio?
- Good benefit to risk ratio
How is the compliance for fluoride tablets?
- Poor compliance
How is the compliance for fluoride mouthrinses?
- Generally good compliance
IS the cost benefit ratio for fluoride mouthrinses high or low?
- Low
Give an example of a fluoride varnish?
- Duraphat
Fluoride varnish has a high fluoride concentration. What is it?
- Sodium fluoride 50mg/ml = 22600 ppm F-
Since fluoride varnishes are painted onto the tooth in a varnish form. What does this allow?
- Sustained contact with the tooth
How do fluoride varnishes work?
- Colophony resin hardens in contact with saliva to maintain contact of fluoride with the tooth
What are the kinetics of fluoride absorption? (3)
- Rapid absorption on tooth surface (enamel and dentine)
- Increase in fluoride content of enamel up to 77% after a single application
- Progressive release of fluoride over several months
How does calcium fluoride work?
- During an acid attack the pH falls
- Fluoride products have a greater bioavailability the lower the pH
- Therefore as the pH lowers you will get a release of fluoride ions into the oral environment
- The presence of the fluoride ions helps to drive the process of remineralisation
What are acidulated mouthrinses and how do they work?
- Low pH mouthrinse
- Stimulated mild demineralisation on tooth surfaces
- P r esence of fluoride remains
- Effective means of getting fluoride into teeth
- More so than non acidulated rinses (because of the low pH)
Give an example of fluoride boosters?
- Casein Phosphopeptide - Amorphous Calcium Phosphate (CPP-ACP) - not suitable for those with milk allergies
Fluoride boosters (e.g. CPP-ACP) are not suitable for people with what allergy?
- Milk allergies
Where can fluoride boosters be used?
- At home or in office in trays
Fluoride boosters are useful in which markets?
- Markets with no access to high fluorides (no access to licenced high fluoride products such as Duraphat)
Some dental materials are able to facilitate fluoride release. Give an example of these?
- Glass ionomer/resin modified
There is an ‘early washout’ of fluoride from GI/RMGI. What does this mean?
- Fluoride is gone around 4 weeks from surface layer
What actual amount of fluoride in GI/RMGI is very small but sustained. What does this help us achieve?
- Helps us meet the little but often goal
What is a ‘slow release device’?
- Devices that are attached to the oral environment b the cementing to the tooth surface or by incorporating into an appliance that is worn where fluoride can be released in a controlled manner over a period of time
What is the historical view of the effect of fluoride at the tooth surface?
- The role of fluoride was around the incorporation of fluoride into the apatite crystal structure during amelogenesis and the resultant fluorapatite being more resistant to acid solution and demineralisation
What is the contemporary philosophy of the effect of fluoride at the tooth surface?
- Centres more around the presence of fluoride during the caries process and how it impacts and interferes with the demineralisation/remineralisation dynamic on the tooth surface
What does the principle mechanism of fluoride in caries control rely upon? (3)
- Fluoride in saliva
- Fluoride at plaque fluid and tooth interface
- Fluoride in fluids around lesion mineral crystals
The oral reservoir of fluoride is small but it can be optimised by…? (2)
- Delivery of fluoride to tooth surface, plaque and plaque fluid - fluoride boosting
- Maintaining fluoride levels (frequency of exposure)
What are the factors that determine the anticaries activity of fluoride toothpaste? (4)
- Fluoride concentration
- Frequency of application
- Rinsing behaviours
- When brushing takes place
Studies have shown that the more you increase the F- conc entration in toothpaste the netter effect it has. What is the % reduction in caries for every 500ppm F increase in F concentration?
- 6-7% reduction in caries
use of low fluoride formulations provide less anticaries benefit
Does frequency of application of fluoride has an impact on caries activity?
- Yes, more frequent brushing results in lower caries increments
What will happen if a patient rinses after brushing but with a small volume of water?
- Will remove excess fluoride
- But maintains fluoride reservoir in the mouth
What will happen if a patient rinses after brushing with a large volume of water?
- Removes excess fluoride
- But also reduces the volume of fluoride in the oral reservoir in the mouth
What are the characteristics for optimal toothbrushing? (3)
- Twice daily
- Not rinsing with water
- 1500ppm F toothpaste
What are the characteristics for sub-optimal toothbrushing? (3)
- Once daily
- Rinsing with water
- 1000ppm F toothpaste
IS the quantity of toothpaste applied to the teeth strongly associated with efficacy?
- No
What is the issue with using fluoride?
- If fluoride is swallowed there is a risk of developing fluorosis
Acute toxicity of fluoride is very rare. In which population is this a potential problem?
- In very young children
What can chronic toxicity of fluoride cause?
- Developmental defect of enamel
How much fluoride do young children need to swallow to risk fluorosis?
- General consensus is around 0.1mg f/kg body weight
- 1mg per day for 1 year old
- 2mg per day for 5/6 year old
Is it still possible to develop fluorosis at the recommended daily intakes of 0.05-0.07 mg f/kg?
- Yes
- There is no lower limit below which fluorosis does not occur
- There appears to be a dose response between fluoride exposure and fluorosis severity
How much of a 1500 ppm F toothpaste does a 1YO need to swallow to risk fluorosis?
0.66g
How much of a 1500 ppm F toothpaste does a 5-6YO need to swallow to risk fluorosis?
- 1.33g
How much of a 500 ppm F toothpaste does a 1YO need to swallow to risk fluorosis?
2.00g
How much of a 500 ppm F toothpaste does a 5-6YO need to swallow to risk fluorosis?
4.00g
How many 1mg fluoride tablets does a 1YO need to swallow to risk fluorosis?
1 tablet
How many 1mg fluoride tablets does a 5-6YO need to swallow to risk fluorosis?
2 tablets
How much 1mg/l fluorinated water does a 1YO need to swallow to risk fluorosis?
1 litre
How much 1mg/l fluorinated water does a 5-6YO need to swallow to risk fluorosis?
2 litres
How much of a fluorinated mouth rinse does a 1YO need to swallow to risk fluorosis?
- Not recommended for children less than 6 years
How much of a fluorinated mouth rinse does a 5-6YO need to swallow to risk fluorosis?
- Not recommended for children less than 6 years
Is the quantity of topical fluoride applied to a tooth strongly associated with efficacy?
- No
- Efficacy is primarily concentration, not dose dependent as oral fluid reservoir is small
Why is brushing after meals the most effective time?
- Most effective time of cariogenic challenge/less readily absorbed
- This is where the pH is lower and stomach is full so more fluoride is available and if it is swallowed it is less readily absorbed
Why is it good to brush your teeth before bedtime ?
- Salivary flow rate is reduced/increased oral retention
Is anti caries benefit topical or systemic?
- Topical
Is increased risk of developing fluorosis topical or systemic?
- Systemic
methods favouring topical delivery whilst minimising ingestion will have the best risk/benefit profile
What can we do to maximise caries benefit but reduce fluorosis risk in young children? (8)
- Keep toothpaste out of reach of young children
- Brush frequently (twice daily; evening and one other time)
- Supervise brushing by young people
- Use a small amount (pea/smear) of paste
- Discourage swallowing
- Brush after meals to minimise effect of fluoride ingestion
- Encourage spitting out, remove slurry; avoid excess rinsing
- Use a lower fluoride formulation if low caries risk, maximise fluoride concentration in relation to risk
Where is there community level caries prevention for children?
- Schools, nureries, play groups
- Community groups, housing estates, local authority…
- Community health professionals, local GMP surgery, health centres, shops, shopping centres
