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ABP Periodontology study materials
ABP Periodontology study resources

ABP Periodontology practice questions

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Question 1Periodontology

Which bacterial species is most strongly associated with the initiation of chronic periodontitis and is considered a red complex organism?

  1. Actinomyces viscosus
  2. Streptococcus mutans
  3. Porphyromonas gingivalis Correct answer.
  4. Veillonella parvula

Explanation

The red complex described by Socransky includes Porphyromonas gingivalis, Tannerella forsythia, and Treponema denticola, organisms strongly linked to periodontitis progression. P. gingivalis is a key keystone pathogen in chronic periodontitis.

Question 2Periodontology

What is the primary mineral component of supragingival calculus?

  1. Sodium chloride
  2. Potassium carbonate
  3. Calcium phosphate Correct answer.
  4. Magnesium sulfate

Explanation

Calculus consists largely of inorganic salts, predominantly calcium phosphate in the form of hydroxyapatite and related crystalline structures. Organic components form a minority of its mass.

Question 3Periodontology

Which clinical measurement defines a periodontal pocket?

  1. Probing depth of 1 mm
  2. Probing depth of 2 mm
  3. Probing depth of 3 mm or less
  4. Probing depth of 4 mm or greater Correct answer.

Explanation

A probing depth of 4 mm or more is generally considered a pocket in most periodontal assessments, since normal sulcus depth is typically 1 to 3 mm. Deeper readings suggest attachment loss or gingival enlargement.

Question 4Periodontology

Which gingival fiber group runs from the cementoenamel junction area coronally and inserts into the free gingiva?

  1. Circular fibers
  2. Transseptal fibers
  3. Dentogingival fibers Correct answer.
  4. Alveologingival fibers

Explanation

Dentogingival fibers extend from the cervical cementum into the free gingiva, helping to maintain gingival adaptation to the tooth. They are one of the principal fiber groups of the gingiva.

Question 5Periodontology

Which index is used to record bleeding on probing as a measure of gingival inflammation?

  1. Mühlemann bleeding index Correct answer.
  2. DMFT index
  3. CPITN
  4. Silness-Löe plaque index

Explanation

The Mühlemann and modified sulcular bleeding indices grade bleeding after gentle probing as a sign of gingival inflammation. The other listed indices measure plaque, caries, or treatment need.

Question 6Periodontology

What is the recommended probing force for accurate periodontal pocket measurement?

  1. 50 g
  2. 5 to 10 g
  3. 100 g
  4. 25 g Correct answer.

Explanation

A controlled probing force of about 0.25 N (approximately 25 g) is recommended to balance sensitivity and patient comfort. Heavier forces tend to overestimate depth by penetrating the junctional epithelium.

Question 7Periodontology

Which systemic condition is classically associated with gingival enlargement?

  1. Diabetes insipidus
  2. Phenytoin therapy Correct answer.
  3. Iron deficiency anemia
  4. Hyperthyroidism

Explanation

Phenytoin is a well-known drug causing gingival overgrowth, along with cyclosporine and calcium channel blockers. The enlargement is thought to relate to fibroblast proliferation and collagen accumulation.

Question 8Periodontology

Which microorganism is most associated with localized aggressive periodontitis in adolescents?

  1. Streptococcus sanguinis
  2. Fusobacterium nucleatum
  3. Aggregatibacter actinomycetemcomitans Correct answer.
  4. Lactobacillus acidophilus

Explanation

Aggregatibacter actinomycetemcomitans, particularly serotype b, is strongly associated with localized aggressive periodontitis. It produces leukotoxin that impairs neutrophil function.

Question 9Periodontology

A 45-year-old patient has generalized probing depths of 5 to 6 mm with bleeding and radiographic bone loss of 30 percent. Which diagnosis is most appropriate?

  1. Periodontal health
  2. Stage I periodontitis
  3. Gingivitis
  4. Stage III periodontitis Correct answer.

Explanation

Generalized pocketing with bleeding and moderate bone loss fits Stage III periodontitis, which involves attachment loss of 5 mm or more and potential tooth loss. Gingivitis lacks attachment loss and Stage I involves mild loss.

Question 10Periodontology

Which of the following is the most appropriate initial nonsurgical treatment for chronic periodontitis?

  1. Systemic antibiotics alone
  2. Scaling and root planing Correct answer.
  3. Immediate flap surgery
  4. Extraction of all involved teeth

Explanation

Scaling and root planing is the cornerstone of nonsurgical periodontal therapy and precedes any surgical evaluation. Antibiotics are adjunctive and surgery is considered only after re-evaluation.

Question 11Periodontology

Which radiographic pattern is most characteristic of periodontitis?

  1. Root resorption
  2. Pulpal calcification
  3. Horizontal bone loss Correct answer.
  4. Periapical radiolucency

Explanation

Periodontitis typically produces horizontal or angular alveolar bone loss visible on radiographs. Periapical radiolucency and pulpal changes relate to endodontic disease.

Question 12Periodontology

Which factor most increases the risk of periodontal disease progression in a patient with diabetes?

  1. Poor glycemic control Correct answer.
  2. Regular dental visits
  3. Use of fluoride toothpaste
  4. Improved glycemic control

Explanation

Poor glycemic control impairs neutrophil function and collagen metabolism, increasing susceptibility to and severity of periodontitis. Good control reduces this risk.

Question 13Periodontology

What does the term 'clinical attachment level' represent?

  1. Distance from the cementoenamel junction to the base of the pocket Correct answer.
  2. Distance from the incisal edge to the gingival margin
  3. Distance from the gingival margin to the mucogingival junction
  4. Distance from the alveolar crest to the apex

Explanation

Clinical attachment level is measured from a fixed reference, the CEJ, to the base of the sulcus or pocket, reflecting true attachment loss. It accounts for gingival margin position, unlike probing depth alone.

Question 14Periodontology

Which surgical procedure aims to reposition the gingival margin apically to increase attached gingiva?

  1. Frenectomy
  2. Crown lengthening for esthetics
  3. Gingivectomy
  4. Apically positioned flap Correct answer.

Explanation

An apically positioned flap moves the gingival margin apically, increasing the zone of attached gingiva. Gingivectomy removes tissue but does not reposition the margin apically in the same way.

Question 15Periodontology

Which organism is part of the orange complex and acts as a bridge between early and late colonizers?

  1. Actinomyces naeslundii
  2. Fusobacterium nucleatum Correct answer.
  3. Porphyromonas gingivalis
  4. Streptococcus oralis

Explanation

Fusobacterium nucleatum is a key bridging organism that coaggregates with both early and late colonizers, facilitating biofilm maturation. It belongs to the orange complex.

Question 16Periodontology

Which clinical sign best distinguishes gingivitis from periodontitis?

  1. Plaque accumulation
  2. Bleeding on probing
  3. Redness of the gingiva
  4. Attachment loss Correct answer.

Explanation

Gingivitis is reversible inflammation confined to the gingiva without attachment loss. Periodontitis is defined by attachment loss, which distinguishes it from gingivitis.

Question 17Periodontology

Which local factor most commonly contributes to gingival inflammation?

  1. Enamel pearls
  2. Tongue thrust
  3. Dental plaque Correct answer.
  4. Bruxism

Explanation

Dental plaque biofilm is the primary etiologic factor for gingival inflammation. Other local factors may modify the response but are not the primary cause.

Question 18Periodontology

A patient reports spontaneous gingival bleeding and has a platelet count of 60,000/µL. Which is the most appropriate next step?

  1. Prescription of antibiotics
  2. Medical referral before elective periodontal treatment Correct answer.
  3. Immediate scaling and root planing
  4. Gingivectomy

Explanation

Spontaneous bleeding with thrombocytopenia suggests a systemic bleeding disorder that requires medical evaluation before elective dental treatment. Proceeding with invasive therapy could cause uncontrolled bleeding.

Question 19Periodontology

Which measurement describes the width of keratinized tissue?

  1. Gingival width from mucogingival junction to gingival margin Correct answer.
  2. Bone sounding depth
  3. Probing depth
  4. Attachment level

Explanation

The width of keratinized tissue is measured from the mucogingival junction to the gingival margin. Attached gingiva width is calculated by subtracting probing depth from this value.

Question 20Periodontology

Which antibiotic is commonly used as an adjunct to scaling and root planing in aggressive periodontitis?

  1. Penicillin V alone
  2. Erythromycin
  3. Amoxicillin with metronidazole Correct answer.
  4. Cephalexin

Explanation

Combination amoxicillin and metronidazole is a well-supported adjunct in aggressive periodontitis because it targets a broad anaerobic spectrum including A. actinomycetemcomitans. It is used together with mechanical debridement.

Question 21Periodontology

Which feature is characteristic of necrotizing ulcerative gingivitis?

  1. Generalized horizontal bone loss
  2. Gingival fibromatosis
  3. Deep periodontal pockets with suppuration
  4. Punched-out interdental papillae with pseudomembrane Correct answer.

Explanation

NUG presents with necrosis of interdental papillae producing punched-out lesions, a gray pseudomembrane, pain, and foul odor. It is often associated with stress, immunosuppression, and poor oral hygiene.

Question 22Periodontology

Which principle best explains why smoking masks periodontal inflammation?

  1. Smoking causes vasoconstriction and reduces bleeding Correct answer.
  2. Smoking eliminates plaque biofilm
  3. Smoking increases gingival blood flow
  4. Smoking increases salivary flow

Explanation

Smoking induces vasoconstriction, which reduces clinical signs such as bleeding and gingival redness despite ongoing destruction. This can mask disease severity and delay diagnosis.

Question 23Periodontology

A patient with a 6 mm pocket on a maxillary molar shows bleeding and 50 percent bone loss but no furcation involvement. Which classification best applies?

  1. Stage II
  2. Stage I
  3. Stage III Correct answer.
  4. Stage IV

Explanation

Interdental attachment loss of 5 mm or more with probing depth of 6 mm and moderate bone loss fits Stage III. Stage IV requires additional complexity such as masticatory dysfunction or severe tooth loss.

Question 24Periodontology

Which mechanism explains why systemic antibiotics alone fail to resolve periodontitis?

  1. Antibiotics are inactivated by saliva
  2. Biofilm bacteria resist penetration and deposits act as a reservoir Correct answer.
  3. Antibiotics cannot reach the oral cavity
  4. Bacteria lack antibiotic targets

Explanation

Subgingival biofilm and calculus harbor bacteria protected from systemic drug levels, so mechanical disruption is required. Antibiotics are therefore adjunctive to scaling and root planing.

Question 25Periodontology

Which outcome best indicates successful periodontal maintenance after active therapy?

  1. Increased tooth mobility
  2. Increased bleeding on probing
  3. Reduced probing depths and stable attachment levels Correct answer.
  4. Progressive bone loss

Explanation

Successful maintenance is reflected by reduced pocket depths, stable clinical attachment levels, and minimal bleeding. Ongoing mobility increase or bone loss indicates disease progression.

Question 26Periodontology

Which term describes the portion of the gingiva that is firmly bound to the underlying periosteum and alveolar bone?

  1. Mucogingival junction
  2. Attached gingiva Correct answer.
  3. Free gingival margin
  4. Interdental papilla

Explanation

Attached gingiva is the keratinized tissue extending from the base of the gingival sulcus to the mucogingival junction, bound to periosteum and bone. The free gingival margin is the coronal edge, the interdental papilla fills the embrasure, and the mucogingival junction is the boundary between attached gingiva and alveolar mucosa.

Question 27Periodontology

Which bacterial species is most strongly associated with the initiation of gingivitis?

  1. Actinomyces viscosus Correct answer.
  2. Porphyromonas gingivalis
  3. Tannerella forsythia
  4. Streptococcus mutans

Explanation

Actinomyces viscosus is a Gram-positive filamentous rod that is an early colonizer and is strongly implicated in the initiation of gingivitis. Porphyromonas gingivalis and Tannerella forsythia are late colonizers associated with periodontitis, and Streptococcus mutans is primarily associated with dental caries.

Question 28Periodontology

Which index is used to assess the severity of gingival inflammation based on bleeding on probing?

  1. Plaque index
  2. Periodontal disease index
  3. Community periodontal index
  4. Gingival index Correct answer.

Explanation

The gingival index (Löe and Silness) scores gingival inflammation based on color, consistency, and bleeding on probing. Plaque index measures plaque, periodontal disease index measures attachment loss, and community periodontal index assesses periodontal status in populations.

Question 29Periodontology

Which of the following is a primary etiology of periodontal disease?

  1. Diabetes mellitus
  2. Dental plaque biofilm Correct answer.
  3. Smoking
  4. Occlusal trauma

Explanation

Dental plaque biofilm is the primary etiologic factor for periodontal disease; without it, periodontitis does not occur. Smoking, diabetes, and occlusal trauma are modifying or contributing factors but are not primary causes.

Question 30Periodontology

Which grading system is used to classify the severity of gingival recession?

  1. Miller classification Correct answer.
  2. Glickman classification
  3. Angle classification
  4. Kennedy classification

Explanation

The Miller classification grades gingival recession based on the extent of root exposure and involvement of the mucogingival junction. Angle classification is for malocclusion, Kennedy for partially edentulous arches, and Glickman for furcation involvement.

Question 31Periodontology

Which instrument is most appropriate for removing subgingival calculus during scaling and root planing?

  1. Sickle scaler
  2. Periodontal probe
  3. Gracey curette Correct answer.
  4. Universal curette

Explanation

Gracey curettes are area-specific and designed for subgingival scaling and root planing, with a curved blade that adapts to root surfaces. Universal curettes can be used but are less adapted; sickle scalers are for supragingival use, and probes are for measurement.

Question 32Periodontology

Which of the following is a characteristic feature of periodontitis as opposed to gingivitis?

  1. Gingival erythema
  2. Bleeding on probing
  3. Presence of plaque
  4. Apical migration of the junctional epithelium Correct answer.

Explanation

In periodontitis, the junctional epithelium migrates apically, leading to attachment loss and bone loss. Bleeding on probing, erythema, and plaque are features of gingivitis and can also be present in periodontitis but do not define it.

Question 33Periodontology

Which of the following is a common side effect of systemic tetracycline used as an adjunct in periodontal therapy?

  1. Gingival overgrowth
  2. Photosensitivity Correct answer.
  3. Renal failure
  4. Tooth discoloration

Explanation

Tetracyclines can cause photosensitivity reactions, among other side effects. Gingival overgrowth is associated with phenytoin, nifedipine, and cyclosporine; tooth discoloration occurs with tetracyclines in developing teeth; renal failure is not a typical side effect.

Question 34Periodontology

A 50-year-old patient presents with a 7 mm pocket on the mesial aspect of a mandibular first molar. Probing depth is 7 mm, and there is 5 mm of clinical attachment loss. What is the most likely explanation for the difference between probing depth and attachment loss?

  1. Gingival enlargement Correct answer.
  2. Gingival recession
  3. Tooth mobility
  4. Furcation involvement

Explanation

Probing depth exceeds attachment loss when the gingival margin is coronal to the cementoenamel junction, as in gingival enlargement. Recession would make attachment loss greater than probing depth. Furcation involvement and mobility do not directly explain this difference.

Question 35Periodontology

Which of the following best describes the purpose of a gingivectomy?

  1. Repositioning of the gingival margin apically
  2. Removal of inflamed gingival tissue to reduce pocket depth Correct answer.
  3. Regeneration of lost periodontal structures
  4. Frenectomy to release tension

Explanation

Gingivectomy involves excision of gingival tissue, often to eliminate suprabony pockets and reduce inflammation. Apical repositioning is a different procedure; regeneration aims to restore lost tissues; frenectomy is unrelated.

Question 36Periodontology

Which of the following is a key difference between chronic and aggressive periodontitis?

  1. Aggressive periodontitis typically affects older adults
  2. Aggressive periodontitis often shows rapid attachment loss and familial aggregation Correct answer.
  3. Chronic periodontitis is more common in younger patients
  4. Chronic periodontitis is always localized

Explanation

Aggressive periodontitis is characterized by rapid attachment loss and bone destruction, often with familial aggregation, and tends to affect younger individuals. Chronic periodontitis is more common in adults and is usually generalized.

Question 37Periodontology

A patient with a history of infective endocarditis requires periodontal surgery. Which precaution is most appropriate?

  1. Antibiotic prophylaxis before the procedure Correct answer.
  2. Delay surgery until the patient is off all medications
  3. Use only local anesthesia without epinephrine
  4. No antibiotic prophylaxis needed

Explanation

Patients with a history of infective endocarditis are at high risk for bacteremia and should receive antibiotic prophylaxis before invasive periodontal procedures. Local anesthesia without epinephrine is unrelated to endocarditis risk.

Question 38Periodontology

Which of the following is a common complication of poor oral hygiene around dental implants?

  1. Peri-implantitis
  2. Gingival recession
  3. Implant fracture
  4. Peri-implant mucositis Correct answer.

Explanation

Peri-implant mucositis is reversible inflammation of the soft tissue around an implant, caused by plaque accumulation. Peri-implantitis involves bone loss and is not merely poor hygiene but progression. Implant fracture and recession are not primarily hygiene-related.

Question 39Periodontology

Which of the following best describes the role of interleukin-1 (IL-1) in periodontal disease?

  1. It stimulates bone resorption and inflammation Correct answer.
  2. It inhibits osteoclast activity
  3. It reduces neutrophil chemotaxis
  4. It promotes collagen synthesis

Explanation

IL-1 is a proinflammatory cytokine that stimulates bone resorption and enhances inflammation, contributing to periodontal tissue destruction. It does not inhibit osteoclasts, promote collagen synthesis, or reduce neutrophil chemotaxis.

Question 40Periodontology

A patient presents with a localized gingival overgrowth on the labial gingiva of the maxillary anterior teeth. The patient is taking nifedipine. What is the most appropriate initial management?

  1. Increase oral hygiene instructions only
  2. Consult with the physician regarding alternative medication Correct answer.
  3. Prescribe systemic antibiotics
  4. Immediate surgical excision

Explanation

Drug-induced gingival overgrowth often resolves after discontinuation or substitution of the offending drug, so consultation with the prescribing physician is the first step. Surgery may be considered after drug modification; hygiene alone is insufficient; antibiotics are not indicated.

Question 41Periodontology

Which of the following is an advantage of using a flap procedure over a gingivectomy for pocket reduction?

  1. It results in less postoperative discomfort
  2. It is simpler and faster to perform
  3. It avoids the need for sutures
  4. It allows better access for root planing and preserves keratinized tissue Correct answer.

Explanation

Flap procedures provide access to root surfaces for thorough debridement and can preserve keratinized tissue, especially in areas where gingivectomy would be contraindicated. They are not necessarily simpler, often require sutures, and may cause more discomfort.

Question 42Periodontology

Which of the following is a characteristic radiographic feature of periodontitis?

  1. Widening of the periodontal ligament space uniformly
  2. Horizontal bone loss Correct answer.
  3. Root resorption
  4. Generalized sclerosis of alveolar bone

Explanation

Horizontal bone loss is a common radiographic pattern of periodontitis, reflecting bone resorption. Sclerosis is not typical; uniform PDL widening is not specific; root resorption is not a primary feature.

Question 43Periodontology

A patient with periodontitis reports that their gums bleed when brushing. Which of the following is the most appropriate initial recommendation?

  1. Rinse with hydrogen peroxide
  2. Apply topical antibiotics
  3. Stop brushing to allow healing
  4. Use a soft-bristled toothbrush and continue brushing Correct answer.

Explanation

Bleeding on brushing indicates inflammation; continuing brushing with a soft brush helps remove plaque and resolve inflammation. Stopping brushing worsens plaque accumulation; hydrogen peroxide and antibiotics are not first-line.

Question 44Periodontology

Which of the following best explains why smoking is a major risk factor for periodontitis?

  1. It increases gingival blood flow
  2. It reduces the immune response and impairs healing Correct answer.
  3. It increases salivary flow
  4. It promotes calculus formation

Explanation

Smoking impairs neutrophil function, reduces antibody levels, and compromises healing, increasing susceptibility to periodontitis. It decreases gingival blood flow, does not increase salivary flow, and its effect on calculus is not the primary mechanism.

Question 45Periodontology

Which of the following is the primary goal of periodontal maintenance therapy?

  1. To perform surgery on a regular basis
  2. To prevent recurrence of disease and maintain attachment levels Correct answer.
  3. To prescribe antibiotics periodically
  4. To eliminate all pockets completely

Explanation

Periodontal maintenance aims to prevent recurrence and maintain stability of attachment. Eliminating all pockets is unrealistic; routine surgery and antibiotics are not goals of maintenance.

Question 46Periodontology

A patient with a 5 mm pocket on a maxillary premolar has bleeding on probing and 30% bone loss. What is the most appropriate initial treatment?

  1. Flap surgery
  2. Scaling and root planing Correct answer.
  3. Extraction
  4. Systemic antibiotics alone

Explanation

Scaling and root planing is the first-line treatment for periodontitis with pockets of this depth. Extraction is too aggressive; surgery is considered after initial therapy; antibiotics alone are insufficient without mechanical debridement.

Question 47Periodontology

Which of the following is a contraindication for periodontal surgery?

  1. History of smoking
  2. Uncontrolled hypertension Correct answer.
  3. Mild gingivitis
  4. Well-controlled diabetes

Explanation

Uncontrolled hypertension increases the risk of bleeding and cardiovascular events during surgery, making it a contraindication until controlled. Well-controlled diabetes and mild gingivitis are not contraindications; smoking is a risk factor but not an absolute contraindication.

Question 48Periodontology

Which of the following best describes the concept of 'critical probing depth' in periodontal therapy?

  1. The depth at which pocket reduction surgery is always indicated
  2. The depth at which attachment loss occurs
  3. The depth at which a pocket will recur after treatment
  4. The depth at which nonsurgical therapy is ineffective Correct answer.

Explanation

Critical probing depth refers to the pocket depth beyond which nonsurgical therapy alone is unlikely to be effective, often considered around 5-6 mm. It does not mandate surgery, nor does it define attachment loss or recurrence.

Question 49Periodontology

Which of the following is a key principle of guided tissue regeneration (GTR) in periodontal therapy?

  1. Suturing the flap coronally to cover the defect
  2. Use of autogenous bone grafts to fill defects
  3. Exclusion of epithelial cells to allow periodontal ligament and bone cells to repopulate Correct answer.
  4. Application of antibiotics to eliminate bacteria

Explanation

GTR uses a barrier membrane to prevent epithelial downgrowth and allow cells from the periodontal ligament and bone to regenerate the attachment apparatus. Antibiotics, bone grafts, and suturing are adjuncts but not the defining principle.

Question 50Periodontology

Which of the following best explains the mechanism of action of locally delivered antimicrobials in periodontal therapy?

  1. They stimulate bone formation
  2. They systemically eradicate periodontal pathogens
  3. They mechanically debride the pocket
  4. They provide high concentrations at the site with minimal systemic effects Correct answer.

Explanation

Local antimicrobials deliver high drug concentrations directly into the pocket, reducing systemic exposure and side effects. They do not eradicate pathogens systemically, debride mechanically, or stimulate bone formation.