NBDHE NBDHE Community Oral Health Principles 2 — Questions and Answers
Question 1: Which index is used to measure the prevalence and severity of periodontal disease in epidemiological studies?
- DMFT index
- Community Periodontal Index (CPI) (Correct answer)
- Plaque Index (PI)
- Gingival Index (GI)
Correct answer: Community Periodontal Index (CPI)
The Community Periodontal Index (CPI) is the WHO-recommended tool for measuring periodontal conditions in population surveys.
Question 2: A community water fluoridation program is considered which level of prevention?
- Tertiary prevention
- Secondary prevention
- Primary prevention (Correct answer)
- Primordial prevention
Correct answer: Primary prevention
Water fluoridation is primary prevention because it prevents disease before it occurs in the population.
Question 3: The 'iceberg concept' in epidemiology refers to:
- The visible cases of disease representing only a fraction of total cases (Correct answer)
- The tip of a disease outbreak in polar regions
- The gradual rise of chronic disease over time
- The cold storage of biological specimens
Correct answer: The visible cases of disease representing only a fraction of total cases
The iceberg concept illustrates that clinically apparent disease cases are far fewer than the total cases existing in a population.
Question 4: Which sampling method ensures every member of a population has an equal chance of being selected?
- Stratified sampling
- Cluster sampling
- Simple random sampling (Correct answer)
- Convenience sampling
Correct answer: Simple random sampling
Simple random sampling gives every individual an equal and independent chance of selection, minimizing selection bias.
Question 5: Sensitivity of a screening test refers to its ability to:
- Correctly identify those without the disease
- Correctly identify those with the disease (Correct answer)
- Predict future disease risk
- Measure disease severity
Correct answer: Correctly identify those with the disease
Sensitivity is the proportion of true positives correctly identified (true positive rate) among all diseased individuals.
Question 6: The Healthy People initiative sets national health objectives for the United States on a:
- 5-year cycle
- 10-year cycle (Correct answer)
- Annual cycle
- 20-year cycle
Correct answer: 10-year cycle
Healthy People releases national health objectives every 10 years (e.g., Healthy People 2020, 2030).
Question 7: Which fluoride delivery method provides the HIGHEST concentration of fluoride?
- Community water fluoridation (0.7 ppm)
- Fluoride toothpaste (1,000–1,500 ppm)
- Professionally applied fluoride varnish (22,600 ppm) (Correct answer)
- Fluoride mouth rinse (225 ppm)
Correct answer: Professionally applied fluoride varnish (22,600 ppm)
Professionally applied fluoride varnish contains approximately 22,600 ppm fluoride, the highest concentration among common delivery methods.
NBDHE NBDHE Community Oral Health Principles 2
Which index is used to measure the prevalence and severity of periodontal disease in epidemiological studies?