1. Dental public health, epidemiology and prevention

Question 1

What is prevalence?

Answer 1

The proportion of individuals with disease (cases) in a population at a specific point in time.

Question 2

What is incidence?

Answer 2

The number or proportion of individuals in a population who experience new disease during a specific time period

Question 3

What is a trend?

Answer 3

The changes or differences in the prevalence or incidence of disease with respect to time.

Question 4

In 2013, what proportion of 15 and 12 year olds had “obvious decay experience”?

Answer 4

In 2013, nearly a half (46%) of 15 year olds and a third (34%) of 12 year olds had “obvious decay experience” in their permanent teeth.

This is a reduction from 2003, where 56 % and 43% comparably.

Question 5

In 2013, what proportion of 5 and 8 year olds had obvious decay experience in their primary teeth?

Answer 5

Nearly a third (31%) of 5 year olds and nearly a half (46%) of 8 year olds had obvious decay experience in their primary teeth.

Untreated decay into dentine in primary teeth was found in 28% of 5 year olds and 39% of 8 year olds.

Question 6

What is the evidence that sugar causes caries?

Answer 6

There is clear and extensive evidence of the relationship between the frequency and amount of sugar consumption and the prevalence and severity of dental caries:

• epidemiological data show a correlation between sugar consumption and caries on a national basis.
• caries prevalence is higher in communities with high sugar intake e..g sugar cane and confectionary industry workers
• caries prevalence increases following introduction of a sugar-containing diet in isolated communities e.g. the Inuit, island communities such as Tristan de Cunha
• experimental clinical studies (such as Vipeholm Study) investigating the relationship between sugar intake and dental caries show positive correlation between consumption of sugar (between meals and at meals) and caries increment.
• The Hopewood House study was a dental survey of children in Australia that demonstrated a link between diet and tooth decay. The study found that children who were raised at Hopewood House on a lacto-vegetarian diet had a low prevalence of dental caries compared to children in state schools. However, when the children left the school and began eating a diet with sugar, their decay rate increased to match that of children in state schools.
• Caries decreases following restriction of sugar, e.g. wartime diets.

Question 7

What is the critical pH for enamel? What happens at pH below it?

Answer 7

pH 5.5
Net loss of calcium and phosphate ions below critical pH - demineralisation.

Question 8

What factors influence cariogenicity of foods? (2)

Answer 8

Cariogenic potential is related to consistency: sticky retentive foods are more cariogenic than liquid non-retentive forms, e.g. toffee is more cariogenic than chocolate.

The frequency of consumption is crucial.
> Snacking or grazing results in plaque pH being below the point where net outflow of calcium and phosphate ions from the tooth surface occurs for prolonged periods.

Question 9

What type of sugar is the main culprit for caries?

Answer 9

Non-milk extrinsic sugar consumption.

Question 10

What are the types of non-sugar sweeteners and are they useful?

Answer 10

Non-sugar sweeteners are non-cariogenic and useful sugar substitutes.

Bulk sweeteners: e.g. sorbitol and xylitol, provide calories and bulk. (chewing gum, sweets, medicines)

Intense sweeteners: e.g. saccharin and aspartame are calorie free, popular in ‘slimmers’ food.

From dental POV, bulk and intense sweeteners are non-cariogenic and therefore useful sugar substitute, but use of artificial sweeteners also perpetuates the craving for sweet foods.

Question 11

Why is sugar-free chewing gum useful in caries prevention?

Answer 11

Sugar-free chewing gum stimulates saliva and thus increases salivary buffers and enhances washout of sugar.
May be useful but not prime caries preventive measure.

Question 12

Are non-sugar carbonated beverages a good alternative?

Answer 12

No sugar, but carbonated drinks have pH 2-3 and can cause marked loss of tooth structure via erosion - an increasing problem in teenagers.

Question 13

What systemic (pre-eruptive) effect does fluoride have?

Answer 13

Fluoride ions are incorporated into enamel structure in the form of fluor-apatite during tooth formation.
This decreases the mineral solubility.

Question 14

What topical (post-eruptive) effect does fluoride have?

Answer 14

Fluoride ions are associated with the tooth surface post eruption. The fluoride interaction with hydroxylapatite is complex; fluoride interacts with the tooth structure either by incorporation into the crystal lattice or by binding to crystal surfaces. Calcium fluoride at the tooth surface not only reduces the solubility of the apatite but also encourage remineralisation.

Whilst fluoride may also cause decreased acid production by cariogenic bacteria, its effect on mineral solubility is of much greater clinical significance.

Historically, it was thought that fluoride availability during tooth formation for incorporation into the hydroxyl-apatite was most important. It is now realised the topical effect at the tooth surface post eruption is very important. Thus, methods that apply fluoride on a regular (daily) basis are most effective against caries.

Question 15

What is the evidence that fluoride prevents caries?

Answer 15

• Caries prevalence is lower where fluoride is present naturally in the water supply at the optimum level of 1ppm.
• Additional fluoride to the water supply to the optimum level of 1 ppm is effective in reducing the prevalence of dental caries.
• Fluoride-containing toothpastes are effective in preventing caries.
• Fluoridated milk is beneficial to school children, especially their permanent dentition.
• Supervised regular use of fluoride mouth-rinse is associated with a reduction in caries increment in children.

Question 16

What do most formulations of fluoride toothpaste contain?

Answer 16

Sodium fluoride (NaF)
Sodium monofluorophosphate (SMFP)
or a combination of both., at a conc of either 1000ppm or 1500ppm

Used 2x daily, can reduce caries incidence by around 30%.

Question 17

What are the 2 different concentrations of fluoride mouthwashes?

Answer 17

1) NaF at 0.05% for daily use

2) NaF at 0.2% for weekly use.

Daily use is preferred. Pt advised to use at different time from brushing.

Question 18

What are indications for fluoride mouthwashes?

Answer 18

Teenagers with high caries activity: patients prone to root caries, e.g. xerostomia: non-carious tooth surface loss: dentine hypersensitivity.

However, there is some concern and evidence that alcohol-containing mouthwashes may be carcinogenic.

Question 19

Why are fluoride varnishes useful?

Answer 19

2.2% NaF (22 600ppm) applied professionally 2-4 times a year have ability to substantially reduce tooth decay in children.
Increases availability of topical fluoride.

A number of systematic reviews conclude that applications two or more times a year produce a mean reduction in caries increment of 37% in the primary dentition and 43% in the permanent dentition.

Question 20

What is fluorosis?

Answer 20

Fluorosis or mottled enamel may occur due to excessive intake of fluoride during tooth formation.

In the UK, fluorosis is most likely to occur due to excessive consumption of fluoridated toothpaste.
For this reason, volume of toothpaste used by children should be restricted to a pea/smear amount (according to age) at each brushing and children discouraged from swallowing paste.

Fluorosis results in hypomineralisation and affects mainly the permanent dentition.

Effects range from barely noticeable ‘white flecks’ to brown stains in more severe cases.

Mild forms may diminish with time but can be markedly improved by etching and polishing. Most severe cases may require veneers.

Question 21

What is the appearance of fluorosis?

Answer 21

Effects range from barely noticeable ‘white flecks’ to brown stains in more severe cases.

Question 22

How can you treat the appearance of fluorosis?

Answer 22

Mild forms may diminish with time but can be markedly improved by etching and polishing.

Most severe cases may require veneers.

Question 23

What is the antidote fluoride consumption at <5mg and >5mg F/kg body weight?

Answer 23

<5 mg F-/kg body weight - drink large volume of milk and seek medical advice

> 5mg F-/kg body weight - refer to hospital for gastric lavage without delay

Question 24

What are the effects of smoking on oral health?

Answer 24

• There is a dose-response relationship btw tobacco use and risk of mouth cancer
• There is some evidence that stopping smoking after diagnosis improves mouth cancer survival
• White patches occur on the oral mucosa 6 times more frequently in smokers than non-smokers
• Smoking causes cellular changes within the oral epithelium, which most commonly presents clinically as smoker’s keratosis.
• Smokers are 2.5 to 5 times more likely to develop periodontal disease than non-smokers. These odds may be even higher in younger people.
• There is evidence of a direct correlation between the number of cigarettes and the risk of developing periodontitis
• Reduced gingival redness and oedema in smokers (due to the vasoconstrictive effects of nicotine) may mask underlying attachment loss.
• Acute necrotizing ulcerative gingivitis occurs predominantly in smokers
• Sinusitis occurs 75% more frequently in smokers than in non-smokers
• Taste and olfactory senses are dulled in smokers
• Tooth staining is more common in smokers
• Smokers are predisposed to halitosis
• Wound healing is delayed in smokers - dry sockets occur more commonly in smokers
• Osseointegrated implants are significantly more likely to fail in patients who smoke
• The outcome of most forms of periodontal therapy, including root planing, flap surgery, guided tissue regeneration and local antimicrobial therapy, is less favourable in smokers than in non-smokers.

Question 25

What is the brief advice (30 seconds) you can give for smoking?

Answer 25

‘Ask, Advise, Act’
1. Establish and record smoking status (ASK)
2. Advise on the personal benefits of quitting (ADVISE)
3. Offer help by signposting to local stop smoking service (ACT)

Follow-up of pts is important and the dental team is well placed to assist because ongoing and regular contact.

Nicotine Replacement Therapy (NRT) in the form of patches, chewing gum and nasal sprays increases quit success rates. Other drugs, such as bupropion and varenicline, may also help smokers quit.

Question 26

What is smokeless tobacco (ST) and why is it bad?

Answer 26

These are products that are chewed, sucked or inhaled.

ST contains carcinogens, and therefore increases risk of mouth cancer, potentially malignant disorders and gingival recession.

In SEA - chewing tobacco with is either chewed alone or with betel quid/paan.

Question 27

What is the link of alcohol consumption and oral health?

Answer 27

High alcohol intake is associated with an increased risk of developing mouth cancer, potentially malignant disorders, periodontal disease, caries and xerostomia.

Used in combination, alcohol and tobacco exert a synergistic effect that substantially increases the risk for mouth cancer.

Alcoholism may lead to trauma, and can damage the liver and bone marrow resulting in excessive bleeding during dental treatment.

Dental anaesthetics may not work well in the alcohol abuser and may be carried into the bloodstream more rapidly, requiring additional injections.

Question 28

What questions can you ask to screen for alcohol?

Answer 28

How often do you have a drink containing alcohol?
How many units of alcohol do you drink on a typical day?
How often do you have six or more units of alcohol in a single day?
In the last year, have you failed to do something that you would normally do because of drinking too much alcohol?
How often in the last year were you unable to remember what happened the previous night because of drinking too much alcohol?

Question 29

What is the CAGE acronym and what is it used for?

Answer 29

1. Have you ever felt you needed to Cut down on your drinking?
2. Have people Annoyed you by criticizing your drinking?
3. Have you ever felt Guilty about drinking?
4. Have you ever felt you needed a drink first thing in the morning (Eye-opener) to steady your nerves or to get rid of a hangover?

Question 30

How many units is:
1 normal half pint beer 4%?
1 shot?
Small glass of wine?
440ml of beer 4.5%?
Medium glass of wine? 12.5%?
Large glass of wine 250ml 12.5%?
Bottle of wine 750ml 12.5%
Bottle of spirits 750ml 40%

Answer 30

1 normal half pint beer 4%? - 1 unit
1 shot? - 1 unit
Small glass of wine 125ml? - 1.5 units
440ml of beer 4.5%? - 2 units
Medium glass of wine 175ml? 12.5%? 2 units
Large glass of wine 250ml 12.5%? 3 units
Bottle of wine 750ml 12.5%? 9 units
Bottle of spirits 750ml 40%? 30 units

Question 31

What can stimulants like ecstasy, amphetamines and cocaine cause individuals to do and the dental implications?

Answer 31

Clench and grind their teeth, resulting in tooth wear, temporomandibular disorders, loose and cracked teeth and damage to the tooth roots and gums.

Users of stimulants often also experience chronic dry mouth resulting in increased consumption of sugary drinks.

Many drugs cause users to crave sweet foods but their lifestyle often ignores the importance of oral care.

Question 32

What is “meth mouth”?

Answer 32

Methamphetamine causes the saliva glands to stop producing saliva resulting in an extremely dry mouth and enamel damage (‘meth mouth’).

Question 33

How are the dental implications of heroin?

Answer 33

Heroin is known to cause serious oral health problems and in chronic long-term users, carious and missing teeth and periodontal disease are evident.

Methadone a substitute for heroin needs to be prescribed as sugar-free by medical practitioner.

Question 34

What oral problems can be common in people with HIV/AIDs?

Answer 34

Majority of oral conditions arise because of immune defects.

• Oral warts (which can also progress to mouth cancer)
• Herpes (‘cold sores’)
• Oral hairy leukoplakia
• Candidiasis (thrush)
• Ulcers
• Periodontal disease (periodontitis and gingivitis).
• In addition, bacterial infections that begin in the mouth can become more serious and, if not treated, spread into the bloodstream. This can be particularly dangerous for people living with HIV/AIDS who may have compromised immune systems.

May experience dry mouth, which increases risk of caries and candidiasis and can make chewing, eating, swallowing and even talking difficult.

Some HIV medications can cause dry mouth.

Question 35

How can you identify dental neglect? (NICE 2009 guidelines)

Answer 35

1. The parent’s persistent failure to obtain NHS treatment for their child’s dental caries when such NHS services were available, and
2. the possibility of child maltreatment due to an absent or unjustifiable explanation for a child’s oral injury.

Question 36

What is dental neglect?

Answer 36

Dental neglect is the wilful or persistent failure to meet a child’s or vulnerable person’s basic oral health needs by not seeking or following through with necessary treatment to ensure a level of oral health that allows function and oral health (freedom from pain and infection).

Question 37

What can be prescribed to prevent toothwear?

Answer 37

Night mouthguards

Question 38

What is the recall intervals for children and adults?

Answer 38

For under 18 - between 3 and 12 months

For over 18 - between 3 and 24 months

Question 39

What factors complicate disease prevention in older patients? (4)

Answer 39

1. Plaque control
   > gingival recession; migrated and tilted teeth increase the number of inaccessible surfaces.
   > partial denture increase plaque retention.
   > poor eyesight and reduced dexterity make toothbrushing difficult
   > polypharmacy is common in the older pt; some drugs reduce salivary low.
2. Diet
   > increased tendency to snacking - cakes and biscuits. Particularly prone to recurrent caries and root caries.
3. Denture care
   > encourage removal of dentures at night and good denture hygiene.
   > emphasis the importance of annual dental examination, even if edentulous, because this permits early detection of mucosal disease (e.g. mouth cancer).
4. Advanced restorative care
   > Improved quality of life at old age will demand tooth retention and consequently the need for restorative care. The growing older population may have acquired advanced restorative care such as crowns, bridges and implants in their working age which requires maintenance in their older age (‘the heavy metal brigade”)

Question 40

How does pregnancy impact oral health?

Answer 40

Pregnant women require additional dental hygiene care due to hormonal changes which can affect oral health.

• Pregnancy gingivitis can start within the second month of pregnancy. –> pregnant women are more susceptible to developing periodontal disease during the time when hormonal fluctuations occur.
• Pregnancy granuloma/pregnancy epulis
• Dry mouth -> drink water + use saliva stimulants available over the counter to stimulate saliva flow
• Tooth erosion as a result of repeated gastric acid exposure from severe mourning sickness –> advise to rinse the mouth afterwards with water of a fluoride mouthwash and wait for at least 30 minutes before toothbrushing. Women who suffer from mourning sickness may also want to eat “little and often” but should try to avoid sugary and acidic foods and drinks between meals to protect teeth against caries.
• It is a myth that calcium is lost from the mother’s teeth during pregnancy. Calcium a baby needs if provided by mother’s diet. If dietary calcium were to be inadequate, however, the body accesses this mineral from bone stores. An adequate diet intake of foods such as dairy products and green leafy vegetables will help sufficient calcium intake.
• Smoking in pregnancy can lead to an underweight baby and also affect the unborn baby’s dental health. Maternal smoking increases the risk of cleft lip/palate, as well as other birth defects, in the offspring.
• Maternal oral health may negatively affect pregnancy outcomes.

Question 41

Oral health in special population groups:

Answer 41

• Patients in special population groups such as immunocompromised and hospitalised patients are at greater risk of general morbidity due to oral infections.
• Individuals with diabetes or inflammatory diseases such as rheumatoid arthritis and ankylosing spondylitis are at greater risk for periodontal disease and therefore require additional preventative measures.
• There may be an association between periodontal diseases and cardiovascular disease and stroke, and a range of other systemic iissues.

Children with a cleft lip/palate are more vulnerable to tooth decay, so it is important to encourage them to practice good oral hygiene.