TheoryDental Hygiene NBDHE
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30 free Dental Hygiene NBDHE questions
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Periodontology
In a healthy adult, what is the typical depth of the gingival sulcus measured with a periodontal probe?
Correct — B. A clinically healthy sulcus measures roughly 1 to 3 mm. Readings of 4 mm or more usually indicate attachment loss or a pseudopocket and warrant further evaluation. -
Periodontology
Which group of periodontal ligament fibers chiefly resists vertical (intrusive) occlusal forces by suspending the tooth in its socket?
Correct — C. Oblique fibers are the most numerous PDL group and run coronally from bone to apically on the cementum, resisting masticatory forces that tend to push the tooth into its socket. -
Periodontology
Under the 2017 AAP/EFP classification, a patient with 5 mm clinical attachment loss, probing depths of 6 mm, and bone loss extending to the middle third of the root is best staged as which periodontitis stage?
Correct — D. Interdental CAL of 5 mm or more and radiographic bone loss reaching the mid-third of the root place the case in Stage III, which also carries potential for tooth loss without intervention. -
Periodontology
Subgingival calculus most commonly appears which color when detected clinically?
Correct — C. Subgingival calculus is darkened (brown to black) by blood pigments from inflamed pocket tissue, in contrast to the white-to-yellow supragingival calculus. -
Periodontology
When adapting a Gracey curet for subgingival scaling, what is the correct working-end angulation of the blade face to the tooth surface?
Correct — B. An angulation between 45 and 90 degrees lets the cutting edge engage and remove the deposit; angles below 45 degrees burnish calculus and angles near 90 degrees can gouge. -
Periodontology
A Gracey 13/14 curet is specifically designed to instrument which surfaces?
Correct — C. Gracey curets are area-specific: 13/14 is angled for distal surfaces of posterior teeth, while 11/12 is for mesial posterior surfaces. -
Periodontology
Which inflammatory mediator most directly stimulates osteoclastic alveolar bone resorption in periodontitis?
Correct — A. Prostaglandin E2, along with IL-1 and TNF-alpha, upregulates the RANKL pathway driving osteoclast activity and bone loss; IL-10 is anti-inflammatory. -
Periodontology
Which bacterium of the 'red complex' is most strongly associated with chronic periodontitis?
Correct — D. Porphyromonas gingivalis, a Gram-negative anaerobe of the red complex, is a key periodontal pathogen; S. mutans and Lactobacillus are caries-related. -
Periodontology
The classic clinical triad of necrotizing ulcerative gingivitis (NUG) is pain, gingival bleeding, and which third sign?
Correct — B. NUG presents with necrosis producing punched-out, cratered papillae often covered by a gray pseudomembrane, accompanied by spontaneous bleeding and marked pain. -
Periodontology
A Nabers probe is the instrument of choice for assessing what periodontal finding?
Correct — B. The curved Nabers probe is designed to detect and grade horizontal furcation involvement on multirooted teeth. -
Periodontology
Using the Miller index, tooth mobility classified as Class III indicates movement that is:
Correct — B. Miller Class III is the most severe: horizontal movement exceeding 1 mm combined with the ability to depress the tooth in its socket (vertical mobility). -
Periodontology
Dental plaque is best described scientifically as which of the following?
Correct — B. Plaque is a structured biofilm of microorganisms in an extracellular matrix; the acquired pellicle is the protein film that precedes bacterial colonization. -
Periodontology
Gingival recession is measured from which two landmarks?
Correct — B. Recession is the distance from the CEJ to the gingival margin; adding it to the probing depth yields the total clinical attachment loss. -
Periodontology
A site has a probing depth of 4 mm and the gingival margin is located 2 mm apical to the CEJ. What is the clinical attachment loss at this site?
Correct — B. When recession is present, CAL equals probing depth plus recession: 4 mm + 2 mm = 6 mm of attachment loss measured from the CEJ. -
Periodontology
A site shows a 5 mm probing depth, but the gingival margin sits 1 mm coronal to (above) the CEJ. What is the clinical attachment loss?
Correct — D. When the margin is coronal to the CEJ, subtract that overgrowth: 5 mm probing depth minus 1 mm = 4 mm of true attachment loss. -
Periodontology
After active periodontal therapy, the typical recommended recall interval for periodontal maintenance is:
Correct — B. A 3-to-4-month maintenance interval matches the time biofilm pathogens need to repopulate pockets, helping control recurrent disease. -
Periodontology
When sharpening a curet against a stationary flat stone, the recommended angle between the stone and the blade's face is about:
Correct — D. Holding the stone at roughly 100 to 110 degrees to the face preserves the correct internal blade angle (about 70 to 80 degrees) and a sharp cutting edge. -
Periodontology
Which patient situation is a traditional contraindication for using a magnetostrictive ultrasonic scaler?
Correct — B. Older unshielded pacemakers could be affected by the electromagnetic field of magnetostrictive units; most modern pacemakers are shielded, but verifying the device is prudent. -
Periodontology
Radiographically, primary occlusal trauma most characteristically produces:
Correct — C. Excessive occlusal force widens the PDL space and may thicken the lamina dura without causing the attachment loss seen in periodontitis. -
Periodontology
Bleeding on probing is clinically significant primarily because it indicates:
Correct — B. Bleeding on gentle probing signals ulceration and inflammation of the pocket epithelium and is a useful indicator of disease activity and tissue health. -
Periodontology
The earliest clinically reversible stage of inflammatory periodontal disease, with no attachment or bone loss, is:
Correct — C. Plaque-induced gingivitis is inflammation confined to the gingiva with intact attachment and bone; removing the biofilm resolves it without permanent damage. -
Periodontology
Gingival enlargement (overgrowth) is a well-known side effect of all the following EXCEPT:
Correct — D. Phenytoin (anticonvulsant), cyclosporine (immunosuppressant), and nifedipine (calcium channel blocker) all cause drug-influenced gingival overgrowth; amoxicillin does not. -
Periodontology
Arestin, a locally delivered antimicrobial placed in periodontal pockets, contains which active drug?
Correct — B. Arestin delivers minocycline as bioadhesive microspheres directly into the pocket as an adjunct to scaling and root planing. -
Periodontology
Which systemic condition has a well-documented bidirectional relationship with periodontitis?
Correct — A. Poor glycemic control worsens periodontal inflammation, and severe periodontitis can impair glycemic control, demonstrating a two-way relationship. -
Periodontology
Compared with a universal curet, the working end of an area-specific Gracey curet differs in that:
Correct — C. A Gracey blade is offset at about 70 degrees to the lower shank, so only the lower (outer) cutting edge is used, whereas a universal curet has two usable edges at 90 degrees. -
Periodontology
Fremitus is detected by placing a finger on the facial surfaces of the maxillary teeth while the patient does what?
Correct — B. Fremitus is the palpable or visible movement of a tooth in function; the clinician feels vibration as the patient occludes and moves the mandible. -
Periodontology
Following periodontal surgery, non-resorbable silk sutures are typically removed after about:
Correct — D. Silk and other non-resorbable sutures are generally removed in 7 to 10 days, allowing initial wound healing while limiting plaque accumulation along the suture. -
Periodontology
The primary goal of root planing is to:
Correct — D. Root planing removes residual calculus and softened, contaminated cementum, leaving a smooth surface that discourages biofilm and supports tissue reattachment. -
Periodontology
Localized aggressive periodontitis (now grade C molar-incisor pattern) classically shows rapid bone loss centered on which teeth in an otherwise healthy adolescent?
Correct — C. The molar-incisor pattern of rapid attachment loss around first molars and incisors, often with Aggregatibacter actinomycetemcomitans, is the hallmark of localized aggressive disease. -
Periodontology
The supracrestal tissue attachment ('biologic width') averages about 2 mm and consists of which two components?
Correct — A. The supracrestal attachment is the junctional epithelium (~0.97 mm) plus the connective tissue attachment (~1.07 mm); restorations encroaching on it provoke chronic inflammation.
Dental Hygiene NBDHE sample questions
Tap any question below to reveal the answer and a plain-English explanation.
Periodontology How many sites per tooth are conventionally recorded during a comprehensive periodontal probing examination?
A. Six ✓
B. Three
C. One
D. Twelve
Correct — A. Six sites per tooth (mesiobuccal, midbuccal, distobuccal, and the three corresponding lingual/palatal sites) are probed to capture the full circumferential picture of pocket depths.
Anatomy, Histology & Embryology In the Universal Numbering System, which tooth is designated number 8?
A. Mandibular left central incisor
B. Maxillary left central incisor
C. Maxillary right central incisor ✓
D. Maxillary right first molar
Correct — C. Universal numbering runs 1 to 16 across the maxillary arch starting at the upper right third molar (1), making the maxillary right central incisor number 8.
Radiography X-rays are produced at which component of the dental x-ray tube?
A. The anode target (tungsten) ✓
B. The cathode filament
C. The collimator
D. The aluminum filter
Correct — A. High-speed electrons from the heated cathode strike the tungsten target of the anode, where their kinetic energy converts to x-ray photons (and heat).
Pharmacology Lidocaine and articaine belong to which chemical class of local anesthetics?
A. Esters
B. Opioids
C. Barbiturates
D. Amides ✓
Correct — D. Lidocaine, articaine, mepivacaine, and prilocaine are amide local anesthetics (note the '-caine' preceded by an 'i'); procaine and benzocaine are esters.
Dental Materials Dental amalgam is an alloy formed primarily by combining silver-tin-copper alloy particles with which metal?
A. Gold
B. Aluminum
C. Lead
D. Mercury ✓
Correct — D. Amalgam is produced by mixing (triturating) the powdered alloy with liquid mercury, which wets the particles and forms a workable, hardening mass.
Community Health The U.S. Public Health Service recommended optimal fluoride concentration for community water (updated in 2015) is:
A. 1.5 mg/L
B. 0.7 mg/L (ppm) ✓
C. 2.5 mg/L
D. 4.0 mg/L
Correct — B. Since 2015 the recommended optimal level is a single value of 0.7 ppm, balancing caries prevention with reduced risk of dental fluorosis.
Microbiology & Pathology Which bacterium is most strongly implicated in the initiation of dental caries?
A. Tannerella forsythia
B. Porphyromonas gingivalis
C. Treponema denticola
D. Streptococcus mutans ✓
Correct — D. Streptococcus mutans is the principal initiator of caries because it produces acid from sugars and synthesizes adhesive glucans that build cariogenic biofilm.
Patient Assessment & Care The normal resting adult heart rate range is approximately:
A. 60 to 100 beats per minute ✓
B. 20 to 40 beats per minute
C. 100 to 140 beats per minute
D. 140 to 180 beats per minute
Correct — A. A normal resting adult pulse is 60 to 100 beats per minute; rates below 60 are bradycardia and above 100 are tachycardia.
About the Dental Hygiene NBDHE test
The Dental Hygiene NBDHE measures the Nursing/Medical knowledge you'll actually rely on — tested the way the real exam asks it, not with trick questions. Practising real Dental Hygiene NBDHE-style questions, then sitting a full timed mock exam, is the fastest way to walk in knowing you'll pass.
You will be tested on
- Safe and effective care environment
- Health promotion and maintenance
- Psychosocial and physiological integrity
- Pharmacology, infection control and patient safety
How TheoryPractice helps you pass
- Real exam-style questions with instant, detailed explanations
- Full timed mock exams that mirror the real test format
- Flashcards & quiz modes from the same question bank
- Progress tracking so you know exactly when you're ready
Topics in this question bank
Safe and effective care environment
Health promotion and maintenance
Psychosocial and physiological integrity
Pharmacology, infection control and patient safety
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