Cariology Lecture 7

What is fluorine?

One of 118 chemical atomic elements in the periodic table

A halogen with 7 electrons in the outer shell making it very reactive to other atoms such as calcium and sodium

What is fluoride?

The term used when fluorine is combined with a positively shared counterpart

What is fluorapatite?

A crystalline ionic salt

Ca5(PO4)3F2

What is the recommended/optimal level of fluoride in drinking water?

0.7 milligrams of fluoride per liter of water

Does all water contain fluoride?

Almost all water has some naturally occurring fluoride, usually at levels too low to prevent cavities

How does fluoridated water work?

It bathes teeth with a low level of fluoride throughout the day

This helps to strengthen a tooth’s surface, making it more resistant to decay

What is more resistant to demineralization and acid dissolution following acid production by bacteria, fluorapatite or hydroxyapatite?

Fluorapatite

What does fluoride promote the remineralization and promotion of?

The fluorapatite mineral phase

How does a reduction in demineralization occur with fluoride usage?

Inhibition of microbial growth and metabolism

What enzyme inhibition occurs through fluoride usage?

Reduction of IgA protease synthesis

What is there a reduction of to help decrease bacterial adherence to dental hard tissues with fluoride usage?

Extracellular polysaccharide production

What is community water fluoridation?

A practical, cost-effective and equitable way for communities to improve their residents’ oral health regardless of age, education, or income

The practice of adjusting the amount of fluoride in drinking water to a level recommended to prevent tooth decay

When did water fluoridation start? What has it led to?

1945

A dramatic decline in cavities

What does more than 75 years of research in water fluoridation show?

Community water fluoridation is safe and healthy

What does widespread community water fluoridation do for families and the healthcare system?

Prevents cavities and saves money for both parties

What does drinking fluoridated water do for teeth?

Keeps them strong

Reduces cavities by about 25% in children and adults

Less tooth pain

Fewer fillings and extractions

Fewer missed work and school days

Types of fluoride products

Toothpaste

Mouth rinse

Varnish

Gel and foam

Supplements

Water, salt, and tea fluoridation as well

What can happen if there is too much fluoride exposure while the teeth are still forming?

Dental fluorosis

Outer enamel may have white flecks, spots, or lines

More severe cases can appear orange or brown

Who can develop dental fluorosis?

Only young children

At what age is the enamel of permanent teeth fully formed?

8

What is most often the cause of dental fluorosis?

Overuse or accidental ingestion of toothpaste before age 6

What is the fluorosis index?

Thylstrup-Fejerskov

What are the levels of the fluorosis index?

0-9

What are symptoms of acute toxicity of fluoride?

Respiratory arrest

Cardiac depression

Vomiting

Diarrhea

Salivation

What are human lethal doses of fluoride?

40-80 mg/kg b.w.

Stems from mass poisoning catastrophes

What is an example of fluoride mass poisoning catastrophe?

1943 inmates had eggs prepared with cockroach powder (NaF) instead of milk powder, 47 of 163 died

What is the range of non lethal fluoride overdosing?

0.4-5 mg/kg b.w.

Causes nausea and gastrointestinal effects

What is skeletal fluorosis?

A reversible effect characterized by deficient mineralization of the bone, leading to changes in bone structure and increased risk in fracture

Where is skeletal fluorosis an endemic?

In several countries where the water sources contain naturally high fluoride levels and where water consumption is high due to hot climates

What amount of daily fluoride intake may increase the risk of bone fractures?

Above 6-8 mg/day

Is high fluoride in drinking water associated with with cancer mortality?

No significant association found in studies

What was the outcome of in vitro and in vivo fluoride studies?

Some evidence of genotoxicity

No casual link between high fluoride intake and increased human cancer risk

Are dental caries caused by fluoride deficiency?

No

Fluoride supplementation will never reverse active or gross carious lesions

How can decay be reduced in populations with a high caries risk?

Other measures such as patient counseling and guidance on oral hygiene and food selection must be taken in conjunction with fluoride delivery methods

What is the DMF Index?

Late 1930s suggestion for carious changes and their therapies such as fillings or extractions

What does the D in DMF stand for?

Decayed teeth or tooth surfaces that have been destroyed by caries

What does the M stand for in DMF?

Missing teeth that were removed due to carious decay

What does the F stand for in DMF?

Filled teeth or tooth surfaces due to caries

What is the DMFT index?

The T can be calculated from the combined findings for the tooth from DMF

If there is a D,M, or F component, it is included in the index

The DMFT value equals the sum of corresponding teeth for an individual

What is the DMFT range if wisdom teeth are not included?

0-28

What is the Netherland’s “tale of two towns”?

Tiel water: 1.1 ppm fluoride artificially

Culemborg water: 0.1 ppm fluoride naturally

Lowest caries reduction in pits and fissures (35%)

Highest caries reduction on gingival (86%) and approximately (75%) lesions

If no preventative intervention other than fluoridated water are initiated, tooth surfaces with fast caries progression (pits and fissures) will be cavitated earlier or faster than surfaces with slow caries progression rate (smooth surfaces)

What are the 3 clinical effects of fluoride?

Strengthening enamel

Remineralization

Bacterial inhibition

How does fluoride strengthen enamel?

Fluoride incorporates into the tooth enamel, making it more resistant to acid attacks by transforming the enamels mineral structure into a more acidic-resistant form called fluorapatite

How does fluoride help with remineralization?

It helps replace minerals lost from the enamel due to acid erosion, repairing early signs of tooth decay before cavities form

How does fluoride help with bacterial inhibition?

Fluoride reduces the ability of cavity-causing bacteria to produce acids and stick to the teeth, further preventing decay

What is evidence-based practice?

A life-long learning technique that helps healthcare practitioners continue to improve practice methods and approach to patient care

How many steps in evidence based practice?

5

What is PICO in evidence based practice?

A clear and focused question asking:

Population

Intervention (treatment, diagnosis, or observation)

Comparison

Outcome

What are the 5 steps in evidence-based practice?

Ask a question

Find best evidence

Evaluate evidence

Apply information in combination with clinical experience and patient values

Evaluate outcomes