Fluoridation

Question 1

Fluoride is…

Answer 1

> an anion of the element fluorine (a non-metal)

Question 2

Mechanism of action of fluoride

Answer 2

1) fluoride ions incorporate themselves into the hydroxyapatite crystal making it more resistant to acid dissolution

2) saliva promotes remineralisation of early carious lesion

3) fluoride interferes with the metabolic pathways of bacteria thus reducing acid production

Question 3

Pre-eruptive effects of fluoride

Answer 3

> hydroxyl ions in the hydroxyapatite crystals are replaced with fluoride ions resulting in fluorapatite which is more resistant to breakdown

Question 4

Post-eruptive effects of fluoride

Answer 4

> fluoride encourages uptake of calcium and fluoride ions at the tooth surface which aids the remineralisation of early caries

Question 5

Mode of delivery of fluoride

Answer 5

1) applied by the patient/parent
>toothpaste
> mouthwash
> tablets and drops

2) applied by the dental professional
> varnish
> gels
> indirectly via direct restorative materials such as glass ionomer cement

3) community fluoridation schemes
> water
> milk
> salt

Question 6

Water fluoridation is …

Answer 6

the adjustment of the level of fluoride in public water supplies with the intention of preventing dental caries

Question 7

Features of water fluoridation are …

Answer 7

> optimum of 1ppm (1mg per 1 litre)
artificial water fluoridation reaches 337 million people worldwide
natural water fluoridation reaches 18 million people worldwide
only England have water fluoridation reaching 5.8 million people
no water fluoridation in Scotland

Question 8

History of water fluoridation

Answer 8

> 1915 - less caries, stained teeth due to fluorosis

> 1933 - 1ppm deemed optimal dose to reduce caries and minimise fluorosis

> 1945 - water fluoridation 1ppm trial in Grand Rapids USA - after 6.5 years dental caries incidence decreased by 50%

Question 9

What evidence is there to support the effectiveness of water fluoridation

Answer 9

1) University of York Review 2000
> water fluoridation reduces caries prevalence
> the number of caries affected teeth reduced
> the number of children free from decay is higher when compared to non-fluoridated areas
> water fluoridation is safe - no adverse health effects, no bone fractures, no cancers
> fluorosis prevalence of 48% but only 12.5% of aesthetic concern

2) Effectiveness of Fluoride in Preventing Caries in Adults
> 7 studies of lifelong water fluoridation
> 27% prevention of caries in water fluoridated areas

3) Australian Efficacy and Safety of Fluoridation 2007
> 35% reduction in average dmft (paeds) when using fluoridated water
> 26% reduction in average DMFT (adults) when using fluoridated water
> 15% more children free from caries in primary dentition
> 14% more children free from caries in permanent dentition

4) Cochrane Review 2015

Question 10

Common objections to water fluoridation include …

Answer 10

1) bone fractures

2) fluoridation is a form of mass medication

3) cancers

4) danger to patients on kidney dialysis

5) increase in dental fluorosis

Question 11

Water Fluoridation Act 1985 (or Water Industry Act 1991)

Answer 11

> legislation applying to Scotland regarding water fluoridation

Question 12

Scottish Oral Health Improvement Plan 2018 stance on water fluoridation …

Answer 12

although water fluoridation makes a positive contribution to improvements in OH, due to the practicalities of implementing this method, alternative solutions are more achievable

Question 12

Other community fluoride schemes …

Answer 12

1) school based supervised toothbrushing
> promotes good OH regime, socialises toothbrushing with peers, high participation rates
> expensive, requires cooperation from staff in school, labour intensive

2) fluoride varnish applications
> good evidence for this
> targets at risk children, can be performed outwith the dental clinic and delivered by trained nurses
> requires access to at risk children, doesn’t encourage good OH regimes

3) fluoride tablet and drop distribution
> limited evidence for this
> no advantages
> less likely to be taken up, overdose risk, medicalises dental caries

4) fluoride mouth rinsing in schools
> carried out during the school day, targeted to high risk children
> cannot be used in children who are unable to spit out i.e., < 8 years

5) fluoride in milk
> no advantages
> evidence is outdated

6) fluoridated salt
> old evidence
> no advantages
> encourages increased salt use which contradicts public health messages, cannot be easily target to at risk people