TEST BANK For Darby & Walsh Dental Hygiene:
Theory And Practice 6th Edition Latest Version 2026
1. In a patient with severe chronic periodontitis who smokes 20 cigarettes/day, which of the
following best explains the reduced bleeding on probing (BOP) observed clinically despite active
disease progression?
A. Increased keratinization of the sulcular epithelium due to nicotine
B. Nicotine-induced vasoconstriction masking the inflammatory response
C. Selective suppression of Porphyromonas gingivalis by tobacco smoke
D. Enhanced neutrophil chemotaxis leading to rapid resolution of inflammation
Answer: B
Rationale: Nicotine causes vasoconstriction, which reduces gingival blood flow and thus decreases
bleeding on probing, even in the presence of active inflammation and tissue destruction. Option A is
incorrect because keratinization does not significantly reduce BOP. Option C is false; smoking promotes
periodontopathogens. Option D is incorrect; smoking impairs neutrophil function.
2. A dental hygienist is treating a patient with a history of bisphosphonate therapy for osteoporosis.
The patient requires subgingival scaling. Which of the following is the most critical consideration
to prevent medication-related osteonecrosis of the jaw (MRONJ)?
A. Use of ultrasonic scaler with low power and copious irrigation
B. Avoidance of local anesthesia with vasoconstrictors
C. Pre-treatment antibiotic prophylaxis with amoxicillin
D. Confirmation that the patient has been on a drug holiday for at least 3 months
Answer: A
Rationale: Minimizing trauma is key; ultrasonic scaling with low power and irrigation reduces thermal
and mechanical injury. Option B is not standard; vasoconstrictors are generally safe. Option C is not
indicated unless other conditions warrant. Option D is controversial; drug holidays are not routinely
recommended for osteoporosis patients due to fracture risk.
3. Which of the following histologic features is most indicative of an active periodontitis lesion
versus a stable periodontitis site?
A. Presence of a dense collagen fiber network in the connective tissue
B. Predominance of plasma cells in the connective tissue adjacent to the junctional epithelium
C. A thin, intact junctional epithelium with few rete pegs
D. Presence of Gram-positive cocci in the subgingival biofilm
Answer: B
Rationale: Active periodontitis lesions are characterized by a dense infiltrate of plasma cells, indicating
ongoing B-cell-mediated immune response. Option A describes a stable/healed site. Option C is typical
of health. Option D is not specific; Gram-positive cocci are common in health.
Page 1
,4. A patient with a history of infective endocarditis due to mitral valve prolapse requires dental
hygiene care. According to the latest American Heart Association guidelines, which of the
following procedures would necessitate antibiotic prophylaxis?
A. Supragingival scaling with hand instruments
B. Subgingival scaling using ultrasonic scaler
C. Oral prophylaxis including polishing with a rubber cup
D. Radiographic examination with bitewings
Answer: B
Rationale: The AHA guidelines recommend prophylaxis only for procedures that involve manipulation of
gingival tissue or the periapical region of teeth. Subgingival scaling (ultrasonic or hand) qualifies.
Supragingival scaling and polishing generally do not. Radiographs do not require prophylaxis.
5. A 35-year-old patient presents with generalized attachment loss of 4-6 mm, probing depths of
5-7 mm, and radiographic evidence of moderate horizontal bone loss. The patient reports no
significant medical history and is a non-smoker. Which of the following treatment approaches has
the strongest evidence for arresting disease progression?
A. Full-mouth scaling and root planing (SRP) within 24 hours with adjunctive systemic antibiotics
B. Quadrant-wise SRP over 4 visits with reevaluation at 6 weeks
C. Full-mouth disinfection with chlorhexidine irrigation at each SRP visit
D. Laser-assisted new attachment procedure (LANAP) as monotherapy
Answer: B
Rationale: Quadrant-wise SRP is the traditional gold standard with strong evidence for efficacy. Option
A (full-mouth SRP with antibiotics) may be beneficial in aggressive periodontitis but not necessarily
superior in chronic periodontitis. Option C adds limited benefit. Option D lacks sufficient evidence for
routine use over SRP.
6. When using a piezoelectric ultrasonic scaler for subgingival debridement, which of the following
tip motions is most effective for removing biofilm from root surfaces without causing excessive root
damage?
A. Vertical strokes parallel to the long axis of the tooth
B. Horizontal strokes perpendicular to the tooth surface
C. Oblique strokes at a 45-degree angle to the root
D. Circular motions with light pressure
Answer: A
Rationale: Vertical (or slightly oblique) strokes along the long axis minimize gouging and effectively
remove deposits. Horizontal strokes can create grooves. Oblique at 45° may be less efficient. Circular
motions are not recommended for subgingival use.
7. A patient presents with a radiolucent lesion at the apex of tooth #9 that is well-circumscribed,
round, and less than 1 cm in diameter. The tooth is non-vital and asymptomatic. Which of the
following is the most likely diagnosis?
A. Periapical cemental dysplasia
Page 2
,B. Radicular cyst
C. Periapical granuloma
D. Periapical abscess
Answer: C
Rationale: A periapical granuloma is the most common periapical lesion associated with a non-vital
tooth, often asymptomatic and well-defined. A radicular cyst may appear similar but is less common and
usually larger. Cemental dysplasia is not associated with non-vital teeth. An abscess typically presents
with symptoms and a less defined border.
8. Which of the following systemic conditions is most strongly associated with an increased risk of
peri-implantitis?
A. Controlled type 2 diabetes mellitus with HbA1c <7%
B. History of periodontal disease treated successfully
C. Rheumatoid arthritis managed with methotrexate
D. Uncontrolled diabetes mellitus with HbA1c >8%
Answer: D
Rationale: Uncontrolled diabetes is a well-established risk factor for peri-implantitis due to impaired
healing and increased susceptibility to infection. Controlled diabetes (HbA1c <7%) is not a strong risk
factor. A history of periodontitis is a risk factor, but 'treated successfully' reduces risk. Rheumatoid
arthritis may have some association but is weaker.
9. A dental hygienist is evaluating a patient's risk for developing early childhood caries (ECC).
Which of the following factors carries the greatest weight in a caries risk assessment for a
2-year-old child?
A. Daily consumption of 100% fruit juice from a sippy cup
B. Presence of visible plaque on maxillary anterior teeth
C. Bottle use with milk at bedtime
D. Mother's history of active dental caries
Answer: C
Rationale: Bottle use with milk at bedtime is a classic and potent risk factor for ECC because of
prolonged exposure to fermentable carbohydrates during sleep. Option A is also a risk but less severe
than bedtime bottle. Option B is a sign of existing risk, not a primary factor. Option D is important but
indirect; direct feeding practices are more predictive.
10. In the context of evidence-based practice, a dental hygienist finds a systematic review with
meta-analysis that reports a statistically significant reduction in probing depth with adjunctive use
of a particular antimicrobial. The effect size is small (mean difference 0.3 mm) and the confidence
interval is narrow. Which of the following is the most appropriate interpretation?
A. The intervention is clinically significant and should be adopted for all patients
B. The result is statistically significant but may lack clinical relevance
C. The narrow confidence interval indicates the study is underpowered
D. The small effect size suggests the intervention is ineffective
Page 3
, Answer: B
Rationale: Statistical significance does not guarantee clinical significance. A 0.3 mm reduction in
probing depth is small and may not translate into meaningful patient outcomes. Option A is incorrect
because clinical significance is not established. Option C is false; a narrow CI indicates adequate
power. Option D is incorrect because the effect is statistically significant, just small.
11. A patient presents with generalized gingival hyperplasia that is not associated with any known
medication use. Histological examination reveals an increased number of fibroblasts and collagen
fibers with a chronic inflammatory infiltrate. Which of the following is the most likely diagnosis?
A. Hereditary gingival fibromatosis
B. Pregnancy-associated gingivitis
C. Scurvy-induced gingival changes
D. Pyogenic granuloma
Answer: A
Rationale: Hereditary gingival fibromatosis is a genetic condition characterized by slow, progressive,
benign enlargement of the gingiva due to fibroblast proliferation and collagen accumulation, often
without significant inflammation. Pregnancy-associated gingivitis and pyogenic granuloma are
inflammatory and vascular, not primarily fibrotic. Scurvy causes gingival hemorrhage and ulceration,
not hyperplasia.
12. In the context of dental implant maintenance, which of the following implant surface
modifications has been shown to significantly reduce biofilm accumulation and peri-implant
mucositis compared to machined surfaces?
A. Acid-etched surface with increased roughness
B. Plasma-sprayed titanium surface
C. Hydrophilic surface with nanometer-scale topography
D. Sandblasted and acid-etched surface with micron-scale roughness
Answer: C
Rationale: Hydrophilic surfaces with nanometer-scale topography promote early cell adhesion and
reduce bacterial colonization, leading to less biofilm accumulation. Rougher surfaces (A, B, D)
generally increase biofilm retention and are associated with higher rates of peri-implant mucositis.
13. A dental hygienist is assessing a patient with a history of radiation therapy to the head and
neck. Which of the following salivary changes is most likely to occur due to radiation-induced
damage to salivary glands, and how does this affect the oral microbiome?
A. Decreased salivary flow with increased pH; favors growth of Streptococcus mutans
B. Decreased salivary flow with decreased pH; favors growth of Lactobacillus species
C. Increased salivary flow with decreased pH; favors growth of Candida albicans
D. Increased salivary flow with increased pH; favors growth of Actinomyces
Answer: B
Rationale: Radiation therapy damages salivary glands, causing hyposalivation and reduced buffering
capacity, leading to a lower oral pH. This acidic environment promotes the growth of aciduric bacteria
such as Lactobacillus and Streptococcus mutans, increasing caries risk. Increased salivation is not
typical; pH decreases, not increases.
Page 4
Theory And Practice 6th Edition Latest Version 2026
1. In a patient with severe chronic periodontitis who smokes 20 cigarettes/day, which of the
following best explains the reduced bleeding on probing (BOP) observed clinically despite active
disease progression?
A. Increased keratinization of the sulcular epithelium due to nicotine
B. Nicotine-induced vasoconstriction masking the inflammatory response
C. Selective suppression of Porphyromonas gingivalis by tobacco smoke
D. Enhanced neutrophil chemotaxis leading to rapid resolution of inflammation
Answer: B
Rationale: Nicotine causes vasoconstriction, which reduces gingival blood flow and thus decreases
bleeding on probing, even in the presence of active inflammation and tissue destruction. Option A is
incorrect because keratinization does not significantly reduce BOP. Option C is false; smoking promotes
periodontopathogens. Option D is incorrect; smoking impairs neutrophil function.
2. A dental hygienist is treating a patient with a history of bisphosphonate therapy for osteoporosis.
The patient requires subgingival scaling. Which of the following is the most critical consideration
to prevent medication-related osteonecrosis of the jaw (MRONJ)?
A. Use of ultrasonic scaler with low power and copious irrigation
B. Avoidance of local anesthesia with vasoconstrictors
C. Pre-treatment antibiotic prophylaxis with amoxicillin
D. Confirmation that the patient has been on a drug holiday for at least 3 months
Answer: A
Rationale: Minimizing trauma is key; ultrasonic scaling with low power and irrigation reduces thermal
and mechanical injury. Option B is not standard; vasoconstrictors are generally safe. Option C is not
indicated unless other conditions warrant. Option D is controversial; drug holidays are not routinely
recommended for osteoporosis patients due to fracture risk.
3. Which of the following histologic features is most indicative of an active periodontitis lesion
versus a stable periodontitis site?
A. Presence of a dense collagen fiber network in the connective tissue
B. Predominance of plasma cells in the connective tissue adjacent to the junctional epithelium
C. A thin, intact junctional epithelium with few rete pegs
D. Presence of Gram-positive cocci in the subgingival biofilm
Answer: B
Rationale: Active periodontitis lesions are characterized by a dense infiltrate of plasma cells, indicating
ongoing B-cell-mediated immune response. Option A describes a stable/healed site. Option C is typical
of health. Option D is not specific; Gram-positive cocci are common in health.
Page 1
,4. A patient with a history of infective endocarditis due to mitral valve prolapse requires dental
hygiene care. According to the latest American Heart Association guidelines, which of the
following procedures would necessitate antibiotic prophylaxis?
A. Supragingival scaling with hand instruments
B. Subgingival scaling using ultrasonic scaler
C. Oral prophylaxis including polishing with a rubber cup
D. Radiographic examination with bitewings
Answer: B
Rationale: The AHA guidelines recommend prophylaxis only for procedures that involve manipulation of
gingival tissue or the periapical region of teeth. Subgingival scaling (ultrasonic or hand) qualifies.
Supragingival scaling and polishing generally do not. Radiographs do not require prophylaxis.
5. A 35-year-old patient presents with generalized attachment loss of 4-6 mm, probing depths of
5-7 mm, and radiographic evidence of moderate horizontal bone loss. The patient reports no
significant medical history and is a non-smoker. Which of the following treatment approaches has
the strongest evidence for arresting disease progression?
A. Full-mouth scaling and root planing (SRP) within 24 hours with adjunctive systemic antibiotics
B. Quadrant-wise SRP over 4 visits with reevaluation at 6 weeks
C. Full-mouth disinfection with chlorhexidine irrigation at each SRP visit
D. Laser-assisted new attachment procedure (LANAP) as monotherapy
Answer: B
Rationale: Quadrant-wise SRP is the traditional gold standard with strong evidence for efficacy. Option
A (full-mouth SRP with antibiotics) may be beneficial in aggressive periodontitis but not necessarily
superior in chronic periodontitis. Option C adds limited benefit. Option D lacks sufficient evidence for
routine use over SRP.
6. When using a piezoelectric ultrasonic scaler for subgingival debridement, which of the following
tip motions is most effective for removing biofilm from root surfaces without causing excessive root
damage?
A. Vertical strokes parallel to the long axis of the tooth
B. Horizontal strokes perpendicular to the tooth surface
C. Oblique strokes at a 45-degree angle to the root
D. Circular motions with light pressure
Answer: A
Rationale: Vertical (or slightly oblique) strokes along the long axis minimize gouging and effectively
remove deposits. Horizontal strokes can create grooves. Oblique at 45° may be less efficient. Circular
motions are not recommended for subgingival use.
7. A patient presents with a radiolucent lesion at the apex of tooth #9 that is well-circumscribed,
round, and less than 1 cm in diameter. The tooth is non-vital and asymptomatic. Which of the
following is the most likely diagnosis?
A. Periapical cemental dysplasia
Page 2
,B. Radicular cyst
C. Periapical granuloma
D. Periapical abscess
Answer: C
Rationale: A periapical granuloma is the most common periapical lesion associated with a non-vital
tooth, often asymptomatic and well-defined. A radicular cyst may appear similar but is less common and
usually larger. Cemental dysplasia is not associated with non-vital teeth. An abscess typically presents
with symptoms and a less defined border.
8. Which of the following systemic conditions is most strongly associated with an increased risk of
peri-implantitis?
A. Controlled type 2 diabetes mellitus with HbA1c <7%
B. History of periodontal disease treated successfully
C. Rheumatoid arthritis managed with methotrexate
D. Uncontrolled diabetes mellitus with HbA1c >8%
Answer: D
Rationale: Uncontrolled diabetes is a well-established risk factor for peri-implantitis due to impaired
healing and increased susceptibility to infection. Controlled diabetes (HbA1c <7%) is not a strong risk
factor. A history of periodontitis is a risk factor, but 'treated successfully' reduces risk. Rheumatoid
arthritis may have some association but is weaker.
9. A dental hygienist is evaluating a patient's risk for developing early childhood caries (ECC).
Which of the following factors carries the greatest weight in a caries risk assessment for a
2-year-old child?
A. Daily consumption of 100% fruit juice from a sippy cup
B. Presence of visible plaque on maxillary anterior teeth
C. Bottle use with milk at bedtime
D. Mother's history of active dental caries
Answer: C
Rationale: Bottle use with milk at bedtime is a classic and potent risk factor for ECC because of
prolonged exposure to fermentable carbohydrates during sleep. Option A is also a risk but less severe
than bedtime bottle. Option B is a sign of existing risk, not a primary factor. Option D is important but
indirect; direct feeding practices are more predictive.
10. In the context of evidence-based practice, a dental hygienist finds a systematic review with
meta-analysis that reports a statistically significant reduction in probing depth with adjunctive use
of a particular antimicrobial. The effect size is small (mean difference 0.3 mm) and the confidence
interval is narrow. Which of the following is the most appropriate interpretation?
A. The intervention is clinically significant and should be adopted for all patients
B. The result is statistically significant but may lack clinical relevance
C. The narrow confidence interval indicates the study is underpowered
D. The small effect size suggests the intervention is ineffective
Page 3
, Answer: B
Rationale: Statistical significance does not guarantee clinical significance. A 0.3 mm reduction in
probing depth is small and may not translate into meaningful patient outcomes. Option A is incorrect
because clinical significance is not established. Option C is false; a narrow CI indicates adequate
power. Option D is incorrect because the effect is statistically significant, just small.
11. A patient presents with generalized gingival hyperplasia that is not associated with any known
medication use. Histological examination reveals an increased number of fibroblasts and collagen
fibers with a chronic inflammatory infiltrate. Which of the following is the most likely diagnosis?
A. Hereditary gingival fibromatosis
B. Pregnancy-associated gingivitis
C. Scurvy-induced gingival changes
D. Pyogenic granuloma
Answer: A
Rationale: Hereditary gingival fibromatosis is a genetic condition characterized by slow, progressive,
benign enlargement of the gingiva due to fibroblast proliferation and collagen accumulation, often
without significant inflammation. Pregnancy-associated gingivitis and pyogenic granuloma are
inflammatory and vascular, not primarily fibrotic. Scurvy causes gingival hemorrhage and ulceration,
not hyperplasia.
12. In the context of dental implant maintenance, which of the following implant surface
modifications has been shown to significantly reduce biofilm accumulation and peri-implant
mucositis compared to machined surfaces?
A. Acid-etched surface with increased roughness
B. Plasma-sprayed titanium surface
C. Hydrophilic surface with nanometer-scale topography
D. Sandblasted and acid-etched surface with micron-scale roughness
Answer: C
Rationale: Hydrophilic surfaces with nanometer-scale topography promote early cell adhesion and
reduce bacterial colonization, leading to less biofilm accumulation. Rougher surfaces (A, B, D)
generally increase biofilm retention and are associated with higher rates of peri-implant mucositis.
13. A dental hygienist is assessing a patient with a history of radiation therapy to the head and
neck. Which of the following salivary changes is most likely to occur due to radiation-induced
damage to salivary glands, and how does this affect the oral microbiome?
A. Decreased salivary flow with increased pH; favors growth of Streptococcus mutans
B. Decreased salivary flow with decreased pH; favors growth of Lactobacillus species
C. Increased salivary flow with decreased pH; favors growth of Candida albicans
D. Increased salivary flow with increased pH; favors growth of Actinomyces
Answer: B
Rationale: Radiation therapy damages salivary glands, causing hyposalivation and reduced buffering
capacity, leading to a lower oral pH. This acidic environment promotes the growth of aciduric bacteria
such as Lactobacillus and Streptococcus mutans, increasing caries risk. Increased salivation is not
typical; pH decreases, not increases.
Page 4
