Dental Public Health

Notes

Fluoride

Modes of Action

Systemic (pre-eruptive) Effect

• incorporated into enamel structure in the form of fluor-apatite - ↓ mineral solubility

Topical (post-eruptive) Effect

• Calcium fluoride - ↑ remineralization

Fluoride Toothpaste - Sodium fluoride (NaF) or Sodium monofluorophosphate (SMFP) 

Sodium pyrophosphate - anticalulus agent

Percentage of UK population has reach for fluoridate water : 10%

Fluoride Mouthwashes - 0.05% daily or 0.2% weekly

Fluoride Varnishes - 2.26% F¯ / 22,600ppm → 4 times a year for high caries risk children

Fluoride Toxicity - 5mg F/kg body weight - drink large volume of milk / gastric lavage

Certain Lethal Dosage - 32-64 mg/kg

Use of Duraphat 5% NaF is contraindicated - ulcerative gingivitis and stomatitis

Acidity (critical pH) below which enamel decalcification occurs - 5.5

Most commonly impacted teeth - 3rd molars → 2nd premolars → canines

Abnormal position of crypts - lower 2nd premolar

Ectopic - upper canines

Hyperdontia

Normal shape (supplemental teeth)

Abnormal form (supernumerary teeth) - conical / tuberculate

Alcohol Consumption

All adults - not more than 14 units per week, spread evenly over 3 days or more

Higher risk - more than 35 units per week (women) and more than 50 units per week (men)

Recall Interval

3, 6, 9 or 12 months - younger than 18 y/o

3, 6, 9, 12, 15, 18, 21 or 24 months (longest) - 18 y/o and above

Statistics

Incidence (new cases) = number of individuals who develop a specific disease or experience a specific health-related event during a particular time period (such as a month or year)

Prevalence (all current cases) = total number of individuals in a population who have a disease or health condition at a specific period of time, usually expressed as a percentage of the population

Prevalence = incidence x duration of illness

Hypothesis = proposed explanation for a phenomenon

Null hypothesis = opposite to hypothesis

↓ must know ↓

Common Risk Factor Approach - several chronic diseases have common risk factors

❌ disease-centred approach

Bradford Hill Criteria - causation between exposure (risk factor) & disease / health condition

Hawthorne effect - response bias (being observed)

Berkson bias - selection bias (only assess patients admitted to facility)

Central tendency bias - score / mark middle of scale

① Ordinal / categorical data, ❌ normally distributed ➡ Mann-Whitney U test

                                                              ⤷ more groups ➡ Kruskal-Wallis test
② Binary data ➡ chi-squared test

        ⤷ small sample size ➡ Fisher's exact test
③ Normally distributed continuous data ➡ ANOVA
④ Known risk factor & outcome of interest ➡ Spearman's coefficient
                                   ⤷ normally distributed ➡ Pearson's correlation coefficient

Oral Health Need Assessment (OHNA) - when commissioning new dental services, examination of current services is needed

Evidence-Based Dentistry

3 Key Components of EBD

• Clinically relevant questions
• Systemic review
• Evidenced-based conclusions

Systemic review = reports and recommendations that summarize the effectiveness of particular interventions, treatments or services and often include information about their applicability, costs and implementation barriers

Meta-analysis = consolidated and quantitative review of the large, complex and sometimes conflicting body of literature

Primary prevention - ensure disease does not occur e.g. water fluoridation

Secondary prevention - early intervention in those already affected (incipient stage)

Tertiary prevention - treatment of well-established disease

Confidence interval = precision or uncertainty of study results for making inferences about the population of patients (narrower as sample size ↑)

Efficacy = whether an intervention works in people who receive it, e.g. surgical trials, analgesics

Efficiency = intervention works in people to whom it has been offered, participants may accept / refuse

Phase I, II and III Trials

Phase I : healthy volunteers → safety, appropriate dose level

Phase II : efficacy - condition requiring drug

Phase III : effectiveness - comparing new drug with existing similar drug

Phase IV (not RCT) : monitoring / survey

Internal validity = degree to which the trial has been designed, conducted and analysed well

External validity = precision and extend to which it is possible to generalized the results of publish trial to other setting

Primary source

• Research articles
• Case studies

Secondary sources

• Review articles
• Meta-analysis

Tertiary sources

• Textbook
• Manuals
• Encyclopedia
• Internet
• Popular press

↓ must know ↓