NBDHE Community Oral Health Principles 2 — Questions and Answers

Question 1: Which epidemiological index is most commonly used to measure dental caries prevalence in community surveys?

DMFT index (Correct answer)
OHI-S index
Russell's periodontal index
Gingival index

Correct answer: DMFT index

The DMFT index (Decayed, Missing, Filled Teeth) is the standard WHO-endorsed tool for measuring caries experience in permanent dentition in community oral health surveys.

The DMFT index assigns each permanent tooth a score based on whether it is Decayed (D), Missing due to caries (M), or Filled (F). Community surveys use DMFT to calculate mean scores for populations and track trends over time. The World Health Organization endorses DMFT for standardized international comparisons. For primary dentition, the equivalent is the dmft index (lowercase).

Question 2: What is the primary goal of primary prevention in community dental health?

Preventing disease before it occurs (Correct answer)
Treating existing disease early
Rehabilitating after disease
Monitoring disease progression

Correct answer: Preventing disease before it occurs

Primary prevention aims to prevent the onset of disease entirely through measures such as fluoridation, sealants, and oral hygiene education before disease begins.

In the three-level prevention model, primary prevention targets healthy individuals to prevent disease initiation. In oral health, examples include community water fluoridation, school fluoride rinse programs, pit and fissure sealants, and dietary counseling. It contrasts with secondary prevention (early detection/treatment) and tertiary prevention (restoring function after disease). Dental hygienists play a central role in delivering primary preventive services.

Question 3: Which water fluoride concentration is currently recommended by the U.S. Public Health Service for community water fluoridation?

0.7 mg/L (Correct answer)
1.0 mg/L
1.2 mg/L
0.5 mg/L

Correct answer: 0.7 mg/L

The USPHS updated its recommendation in 2015 to 0.7 mg/L (ppm) for community water fluoridation, replacing the previous range of 0.7–1.2 mg/L.

In 2015, the U.S. Public Health Service established 0.7 mg/L as the single recommended fluoride concentration for community water systems. This update was based on evidence that fluid intake had increased since the original 0.7–1.2 mg/L range was set in 1962, and that fluoride is now available from many other sources. The change aims to maintain caries prevention benefits while reducing the risk of dental fluorosis.

Question 4: The Social Learning Theory used in oral health education suggests that behavior change is most effectively achieved through:

Observational learning and self-efficacy (Correct answer)
Punishment and negative reinforcement
Biological drives alone
Unconscious motivations

Correct answer: Observational learning and self-efficacy

Bandura's Social Learning Theory emphasizes observational learning (modeling) and self-efficacy — a person's belief in their ability to perform a behavior — as key drivers of behavior change.

Albert Bandura's Social Learning Theory (later Social Cognitive Theory) posits that people learn behaviors by observing others and that self-efficacy — confidence in one's ability to perform the behavior — is the strongest predictor of whether they will actually do it. In community oral health education, this means demonstrating proper brushing/flossing techniques and helping patients develop confidence in maintaining those habits. Reciprocal determinism explains the interaction between the person, behavior, and environment.

Question 5: A dental hygienist conducting a community needs assessment should FIRST:

Define the target population and gather existing data (Correct answer)
Design an intervention program
Train volunteers for data collection
Apply for grant funding

Correct answer: Define the target population and gather existing data

The first step in a community needs assessment is defining the target population and reviewing existing data (census records, prior surveys, health department data) before designing any program.

Community needs assessments follow a systematic process: (1) define the community/target population, (2) gather and review existing secondary data, (3) collect primary data if gaps exist, (4) analyze findings, (5) prioritize needs, then (6) plan interventions. Beginning with data collection before understanding the population and what is already known wastes resources. Secondary data sources include U.S. Census Bureau data, state health department reports, school health records, and prior epidemiological surveys.

Question 6: Head Start oral health programs in the United States primarily target which population?

Low-income children ages 0–5 and their families (Correct answer)
Elderly adults in nursing facilities
Adolescents in public high schools
Migrant farm workers of all ages

Correct answer: Low-income children ages 0–5 and their families

Head Start is a federally funded program providing comprehensive services, including oral health, to low-income children from birth to age 5 and their families.

The Head Start program, administered by the U.S. Department of Health and Human Services, serves low-income children from birth to age 5 (Early Head Start covers birth to 3). Oral health is a required component: each child must receive oral health screening, referral, and follow-up treatment. Dental hygienists are often employed in Head Start programs to provide screenings, fluoride varnish, and education to both children and caregivers. The program aims to reduce oral health disparities affecting underserved populations.

NBDHE Community Oral Health Principles 2

Which epidemiological index is most commonly used to measure dental caries prevalence in community surveys?