Fluoride and Tooth Surface medium

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Questions and Answers

What was the initial observation made by Dr. Frederik McKay in Colorado in 1916?

He documented a stain on some children's teeth. (correct)

He linked water source changes to dental health.

He observed tooth decay in all local children.

He identified a new species of bacteria in the water.

What did Churchill discover while investigating the local water in 1931?

Higher fluoride content was associated with mottling. (correct)

There was no fluoride present.

It was linked to cases of severe tooth decay.

It contained harmful levels of lead.

What suggestion did McKay make in 1932 regarding fluoride?

Fluoride is ineffective in reducing tooth decay.

Fluoride causes more dental health issues than it prevents.

Fluoride needs to be completely removed from water supplies.

Fluoride may actually reduce caries. (correct)

Who was assigned by the US public health service to research fluoride's links with mottling and caries reduction?

Dr. Trendley-Dean Signup and view all the answers

What implication did McKay's investigations about mottled teeth have on children's dental health?

Mottled teeth had no greater chance of decay than normally calcified teeth. Signup and view all the answers

What was a major limitation of the research conducted by GV Black on the Colorado Stain?

He was unable to definitively link high fluoride concentrations to mottling. Signup and view all the answers

What was the primary focus of the shoe leather studies conducted between 1930 and 1940?

The relationship between fluoride in water, mottling, and dental caries. Signup and view all the answers

In what year did Churchill identify the higher fluoride content in the local water supply?

1931 Signup and view all the answers

What is the primary way fluoride helps prevent caries?

By making tooth structure more resistant to demineralization Signup and view all the answers

During which stage is fluoride absorbed from systemic sources into the developing tooth?

Pre-eruptive stage Signup and view all the answers

What forms the basis of fluoride's protective effect on teeth?

Fluorapatite Signup and view all the answers

What happens to excess fluoride during tooth development?

It inhibits ameloblast activity, potentially causing fluorosis. Signup and view all the answers

At what stage does fluoride deposition continue at the enamel surface from surrounding tissue fluid?

Maturation stage Signup and view all the answers

Which ion replaces hydroxyl ions in the tooth enamel to strengthen it?

Fluoride Signup and view all the answers

How does fluoride primarily work once the tooth has erupted?

By soaking into the tooth surface topically Signup and view all the answers

Which of the following statements regarding fluoride's role in caries prevention is incorrect?

Fluoride works primarily by systemic absorption. Signup and view all the answers

Which stage of tooth development is characterized by fluoride absorption from swallowed fluoride?

Pre-eruptive stage Signup and view all the answers

What is the effect of fluoride during the maturation stage of tooth development?

It promotes the deposition of fluoride on the enamel surface. Signup and view all the answers

What is the critical pH of fluoroapatite?

4.5 Signup and view all the answers

Why is the uptake of fluoride more significant during the 2-3 years post-eruption?

Teeth are more porous. Signup and view all the answers

What role does fluoride play in the remineralization process?

Produces fluoroapatite. Signup and view all the answers

How does fluoroapatite compare to hydroxyapatite regarding critical pH?

Fluoroapatite has a lower critical pH. Signup and view all the answers

What effect does increased acid attacks have on fluoride uptake?

Increases fluoride uptake. Signup and view all the answers

What structural changes occur in teeth due to the formation of fluoroapatite?

Larger crystals with fewer imperfections. Signup and view all the answers

What happens to the solubility of fluoroapatite compared to hydroxyapatite?

Fluoroapatite is less soluble. Signup and view all the answers

Which factor primarily aids in fluoride penetration into demineralized enamel?

Higher levels of porosity. Signup and view all the answers

Why is it more important to apply fluoride during the progression of caries rather than for prevention?

It easily replaces lost tooth structure. Signup and view all the answers

What interaction does fluoride have with calcium ions?

Prevents deep penetration. Signup and view all the answers

What is the main benefit of professionally applied fluoride treatments in patients with exposed root surfaces?

It reduces the risk of root caries at 2 years Signup and view all the answers

What is the most critical time period for fluoride exposure to potentially lead to fluorosis?

Ages 0-8 years Signup and view all the answers

Which of the following correctly describes fluorosis?

It involves changes in enamel due to excess fluoride ingestion Signup and view all the answers

What is a possible consequence of excess fluoride on enamel formation?

Hypomineralized and hypoplastic enamel formation Signup and view all the answers

Which of the following is NOT a source that can contribute to the risk of fluorosis?

Calcium supplements Signup and view all the answers

Fluorosis can manifest in varying forms which include all of the following EXCEPT?

Staining from diet Signup and view all the answers

What role does fluoride play in the prevention of root caries?

It reduces the risk of developing root caries over time Signup and view all the answers

How does fluoride affect the adherence of bacteria to tooth surfaces?

It reduces the formation of pellicle, making it harder for plaque to accumulate. Signup and view all the answers

What is a suggested outcome of fluoride incorporation during tooth development?

It can lead to shallower pits and more cleansable teeth. Signup and view all the answers

Which patient group is more susceptible to root caries?

Patients with xerostomia. Signup and view all the answers

Which of the following statements about tooth morphology and fluoride is true?

Fluoride incorporation can alter the shape of the tooth to reduce caries risk. Signup and view all the answers

How does fluoride help to prevent root caries during remineralization?

It helps incorporate minerals into both enamel and cementum during remineralization. Signup and view all the answers

What structural changes occur in teeth due to fluoride during development?

Reduced cusp height and shallower pits. Signup and view all the answers

Why are dentin and cementum more susceptible to decay than enamel?

They are less mineralized than enamel. Signup and view all the answers

Which of the following correctly describes the impact of fluoride on dental plaque formation?

Fluoride inhibits pellicle formation, which reduces plaque formation. Signup and view all the answers

What happens when fluoride is used in tooth care products?

It helps to restore minerals in enamel and cementum. Signup and view all the answers

What role does saliva play in relation to fluoride and caries prevention?

Saliva can aid in remineralization but is limited in xerostomic patients. Signup and view all the answers

Study Notes

Fluoride and the Tooth Surface

Fluoride is a naturally occurring element found in water, rocks, soil, and tea.
Fluoride is highly reactive with metals, forming fluoride salts or halides.
Fluoride is not a man-made product.
The chemical symbol for fluorine is F, and its atomic number is 9.
Fluoride is incorporated into the tooth structure as fluoroapatite.

GDC Learning Outcomes

Describe properties of relevant medicines and therapeutic agents, and discuss their use in patient management.
Provide patients with comprehensive preventative education and instruction that encourages self-care.
Underpin all patient care with a preventative approach for long-term oral and general health.
Advise on and apply appropriate preventative materials and treatments.
Describe and evaluate the role of health promotion in changing environments, communities, and individual behaviors, to deliver health gains.
Explain and apply evidence-based prevention appropriately.

Pre-reading: Aetiology of Dental Caries

Caries formation depends on susceptible tooth surface, time, and fermentable carbohydrates and plaque bacteria.

Pre-reading: Histology of Enamel and Dentine

This is a critical pre-reading for understanding the detailed structure and composition of the tissues.

Intended Learning Outcomes

List key milestones in fluoride history and use in caries prevention.
Outline and describe stages in fluoride deposition.
Describe modes of fluoride action.
Explain how fluorosis occurs.
Identify and assess fluorosis severity.

Refresher Session: Normal Enamel Structure

Normal enamel is primarily composed of hydroxyapatite (Ca10(PO4)6(OH)2).
Hydroxyapatite makes up 96% of enamel.
Enamel is a lattice structure made of phosphate and calcium ions.

Refresher Session: Demineralisation

When pH drops below 5.5, hydroxyapatite demineralizes into calcium and phosphate ions.
Extensive demineralization leads to caries.

Refresher Session: Effects of Frequent and Infrequent Sugar Intake

Infrequent sugar intake results in less time below the critical pH, reducing demineralization and caries risk.
Frequent sugar intake results in more time below the critical pH, increasing demineralization and caries risk.

Relevance of Fluoride to Dental Professionals

Determining fluoride's role in dental care.

Fluoride History: Colorado Stain

Frederick McKay documented a staining effect on teeth in Colorado Springs in 1916.
He linked the staining to high fluoride content in the water source.

Fluoride History: Water Sampling

In 1931, local chemist Churchill observed a correlation between high fluoride water and mottling in children of Arkansas.

Fluoride History: Reducing Caries 1932

In 1932, McKay observed that fluoride can, in fact, reduce caries, notwithstanding its ability to cause mottling.

Fluoride History: Shoe Leather Studies/21 Cities Studies (1930-1940)

Dr. H. Trendley Dean, based on McKay's research on fluoride impact, studied the relationship between fluoride in drinking water and caries reduction.
He discovered reduced caries development in areas with 1 ppm (part per million) fluoride. Further study demonstrated the optimal level at 1ppm.
Dr. Dean developed and introduced a 'Fluorosis Index' to measure the severity of tooth mottling.

Fluoride History: Water Fluoridation

The benefits of fluoride discovered led to campaigns promoting water fluoridation.

Fluoride History: Knox Report (1985) and York Report (2000)

Knox Report concluded there was no known link between fluoride and cancer.
York Report reviewed multiple studies and concluded no link between water fluoridation and bone fractures or cancer.

Fluoride History: Cochrane Review (2015)

Found that fluoride in drinking water reduced caries in children's permanent teeth by 26% and in deciduous (baby) teeth by 35%.
73% of studies were related to areas with natural fluoridation.

Modern Day Fluoride

Controversy regarding artificial fluoridation remains.
Approximately 10% of the UK population has fluoride in drinking water.
Fluoride use is well researched and advocated for in caries prevention.

How does fluoride prevent caries?

Fluoride is absorbed into the tooth structure, making it more resistant to demineralization. This happens at multiple stages.
This process involves, depending on the stage of tooth development, the incorporation of fluoride into the tooth, or the use of fluoride to promote remineralization by adding calcium and phosphate to the enamel.

Absorption of Fluoride

Fluoride is generally absorbed during different stages of the tooth development and eruption, depending on whether the fluoride source is systemic or topical (i.e., fluoride is swallowed, or it is applied topically to the teeth).

Why is fluoroapatite important?

Fluoroapatite formation has a lower critical PH.
This makes enamel less soluble and resistant to acid attacks.

How fluoride works in caries prevention

Fluoride replaces hydroxyl ions in hydroxyapatite, forming fluoroapatite, a more resistant compound.

Topical Fluoride Sources

Fluoride is often present in many forms of toothpaste, mouth-rinses and topical applications, such as fluoride varnishes and glass ionomer cements.

Mechanisms of Fluoride Action

Fluoride can directly impact bacterial metabolism by becoming toxic to bacteria (such as streptococcus mutans)
Fluoride can also potentially change the morphology (shape) of the tooth, therefore making it easier to clean.
Fluoride can reduce the formation of pellicle and make the tooth surface less "wettable," which in turn makes it harder for bacteria to become attached to the enamel surface.

Root Caries Recap

Root caries is caused by demineralization of cementum and dentine, and exposure to acids resulting from bacterial activity.
In patients with limited saliva, caries are likely to progress faster in the roots.
Root caries differs significantly from enamel-based caries in that root surfaces are less mineralised.

How Does Fluoride Prevent Root Caries?

Incorporation into surface during remineralization
Reducing surface wettability
Antibacterial effects

What Does Research Say About Topical Fluoride and Root Caries?

Professionally and self-applied fluoride effectively reduces the risk of root caries.
Fluoride is essential to prevent caries in patients with exposed roots.

Fluorosis

Fluorosis is a dental condition resulting from excessive fluoride ingestion during tooth development.
The condition manifests as white or brown discoloration of the enamel, and the severity depends on the level and duration of fluoride intake.

Mechanism of Fluorosis

Excess fluoride inhibits normal ameloblast activity during the matrix formation, and hypomineralized (and hypoplastic) enamel result.
Enamel becomes more porous, absorbing stains more readily, causing discolouration.

What are the aetiological agents that cause fluorosis ?

Dietary fluoride supplements
Drinking water
Toothpastes
Topical applications

Is it Fluorosis? Diagnostic Characteristics

Characteristics of a mild form of fluorosis and of an enamel opacity.

Indices for Recording Fluorosis

Dean Index and Thylstrup/Fejerskov index are used to assess enamel fluorosis.

Summary of Fluoride Deposition

Stages of fluoride deposition, encompassing pre-eruption, and post-eruption stages.

Summary of Fluoride Action

Modes of fluoride actions on teeth, including those on hydroxyapatite, bacterial enzymes, and enamel surface.

Summary of Overall Key Points

Overall key points, summaries, YouTube video references, and thank-you notes.

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Description

This quiz covers the importance of fluoride in dental health, its properties, and its effects on the tooth surface. It emphasizes preventative education and the role of fluoride in patient care and oral health. Participants will learn about the incorporation of fluoride into tooth structure and its relevance in therapeutic practices.