NDEB Exam 2026 update NDEB Solved Questions and Correct
Answers - 150 Questions
Section 1: Diagnosis and Treatment Planning (Questions 1-15)
1 A patient presents with a solitary, painless, radiolucent lesion in the anterior mandible that appears unilocular on
panoramic radiograph. The lesion is non-expansile and asymptomatic. Which combination of diagnostic tests is
most appropriate to establish a definitive diagnosis before treatment planning?
A) Incisional biopsy and cone-beam computed tomography (CBCT)
B) Fine-needle aspiration and MRI
C) Excisional biopsy and periapical radiography
D) Sialography and ultrasound
Answer: A
Rationale: Incisional biopsy is required for histopathologic diagnosis of a radiolucent lesion, and CBCT provides
detailed cortical and spatial assessment, essential for surgical planning. Excisional biopsy is premature without
diagnosis. MRI is not indicated for this lesion, and sialography is for salivary glands.
2 A patient with a history of bisphosphonate therapy for osteoporosis presents with a non-healing extraction
socket and exposed bone. Which diagnostic step is most critical in determining the treatment plan?
A) Serum C-terminal telopeptide (CTX) level measurement
B) Panoramic radiography to assess bony sequestra
C) Microbial culture and sensitivity testing
D) Cone-beam computed tomography (CBCT) with contrast
Answer: A
Rationale: CTX level is a serum marker of bone turnover that helps stratify risk of medication-related osteonecrosis
of the jaw (MRONJ) and guides timing of surgical intervention. While radiography and culture are supportive,
CTX is the key diagnostic test for treatment planning in suspected MRONJ.
3 In a patient with chronic periodontitis and multiple missing teeth, which factor is most critical in determining
whether to recommend implants versus fixed partial dentures?
A) The patient's periodontal stability and compliance with maintenance
B) The number of missing teeth and arch location
C) The patient's age and gender
D) The presence of bruxism and parafunctional habits
Answer: A
Rationale: Periodontal stability and patient compliance are paramount because implant success depends on healthy
peri-implant tissues and long-term maintenance. While other factors influence the decision, uncontrolled
periodontitis is a contraindication for implants, making this the most critical factor.
4 A patient with a history of head and neck radiation therapy presents with xerostomia and rampant caries. Which
treatment planning approach is most appropriate to address the underlying etiology?
A) Prescribe high-fluoride toothpaste and chlorhexidine mouth rinse
B) Recommend salivary substitutes and regular fluoride varnish applications
C) Place full-coverage crowns on all affected teeth
D) Extract all non-restorable teeth and provide complete dentures
,Answer: B
Rationale: Salivary substitutes and fluoride varnish address the root cause (hyposalivation) and prevent further
caries. High-fluoride toothpaste is part of the regimen but not sufficient alone. Restorative treatment must be
preceded by caries control. Extractions are reserved for non-restorable teeth.
5 When developing a treatment plan for a patient with severe dental phobia and multiple carious lesions, which
sequence is most appropriate?
A) Begin with non-invasive preventive therapy, then use behavior management techniques, followed by
restorative care
B) Perform all restorative procedures under general anesthesia in one session
C) Start with extraction of non-restorable teeth, then schedule restorations
D) Refer to a psychologist before any dental treatment
Answer: A
Rationale: A phased approach that first addresses anxiety through behavior management and non-invasive treatment
builds trust and reduces fear. General anesthesia may be needed but is not the first-line approach. Extractions
without caries control can worsen anxiety. Psychological referral can be adjunctive but not prerequisite.
6 A patient presents with a painful, erythematous, and desquamative gingival lesion. Biopsy reveals subepithelial
clefting and a linear deposit of IgG along the basement membrane. Which systemic medication is most likely
indicated as part of the treatment plan?
A) Topical corticosteroids
B) Dapsone
C) Systemic corticosteroids
D) Tetracycline
Answer: C
Rationale: The histopathology and direct immunofluorescence are diagnostic of mucous membrane pemphigoid.
Systemic corticosteroids are the mainstay of treatment for moderate to severe cases. Topical corticosteroids are
used for mild disease. Dapsone is second-line, and tetracycline is not effective.
7 In a patient with a Class III malocclusion and significant facial asymmetry, which diagnostic record is most
essential for planning orthognathic surgery?
A) Cone-beam computed tomography (CBCT) with 3D cephalometric analysis
B) Lateral cephalometric radiograph with traditional analysis
C) Study models mounted on a semi-adjustable articulator
D) Facial photographs and intraoral scans
Answer: A
Rationale: CBCT with 3D cephalometric analysis provides comprehensive assessment of skeletal asymmetry,
airway, and temporomandibular joints, which is critical for surgical planning. Traditional 2D cephalometry is
limited in asymmetry cases. Articulator-mounted models are adjunctive but not primary for skeletal assessment.
8 A patient with a history of infective endocarditis requires dental treatment. Which of the following procedures
necessitates antibiotic prophylaxis according to current AHA guidelines?
A) Scaling and root planing in a patient with excellent oral hygiene
B) Restorative treatment with local anesthesia only
C) Placement of an orthodontic bracket
D) Taking dental radiographs
Answer: A
,Rationale: Scaling and root planing is a procedure that manipulates gingival tissue and may cause bacteremia,
requiring prophylaxis in high-risk patients. Restorative treatment without gingival manipulation, orthodontic
brackets, and radiographs do not require prophylaxis per current AHA guidelines.
9 A patient presents with a recurrent aphthous ulcer that has been present for 4 weeks and is larger than 1 cm. The
ulcer is painful and located on the soft palate. Which diagnostic consideration is most important in treatment
planning?
A) Rule out systemic diseases such as Behçet's disease or inflammatory bowel disease
B) Prescribe topical corticosteroids and reassess in 2 weeks
C) Obtain a biopsy to rule out malignancy
D) Order viral serology for herpes simplex virus
Answer: A
Rationale: The ulcer's size (>1 cm), duration (>4 weeks), and location (soft palate) are atypical for minor aphthous
ulcers and may indicate a major aphthous ulcer or systemic association. Behçet's disease and IBD are common
underlying conditions. Biopsy is indicated if malignancy is suspected, but systemic workup should precede. Topical
therapy is symptomatic but does not address etiology.
10 A patient with a history of cocaine use presents with a midline palatal perforation. Which diagnostic test is
most critical before surgical reconstruction?
A) Biopsy of the perforation margins
B) CT scan of the sinuses and nasal cavity
C) Serologic testing for syphilis
D) Urine toxicology screen
Answer: B
Rationale: CT scan is essential to evaluate the extent of bony destruction and involvement of adjacent structures
(sinuses, nasal cavity) for surgical planning. Biopsy may be needed to rule out other causes (e.g., malignancy,
granulomatosis with polyangiitis), but imaging is critical for reconstruction. Syphilis serology is part of the
differential but not the most critical for surgical planning. Toxicology confirms use but does not guide
reconstruction.
11 A patient presents with a well-defined radiolucency at the apex of tooth #9, which is non-responsive to cold and
electric pulp testing. The adjacent teeth are vital and the lesion is less than 1 cm in diameter. Radiographically,
the lesion appears as a unilocular radiolucency with a thin, sclerotic border. Which of the following diagnoses
is most consistent with these findings, and what is the recommended initial treatment approach?
A) Periapical granuloma; initiate nonsurgical root canal therapy
B) Radicular cyst; perform enucleation and apicoectomy
C) Periapical abscess; prescribe antibiotics and schedule extraction
D) Periapical scar; no treatment indicated, monitor radiographically
Answer: A
Rationale: The lesion is a well-defined radiolucency associated with a non-vital tooth, consistent with a periapical
granuloma (the most common periapical lesion). Radicular cysts are larger (>1 cm) and may show a thick sclerotic
border; however, this lesion is small. Periapical abscess would present with acute symptoms. Periapical scar is rare
and occurs after trauma. Nonsurgical root canal therapy is the first-line treatment for periapical granuloma.
12 In a patient with a history of head and neck radiation therapy for nasopharyngeal carcinoma, which of the
following findings on panoramic radiograph would most strongly indicate the need for a biopsy rather than
assuming osteoradionecrosis?
, A) Irregular, moth-eaten radiolucency with sequestra and periosteal reaction
B) Well-defined radiolucency with a sclerotic border and a central opacity
C) Diffuse, ill-defined radiolucency with cortical erosion and soft tissue mass
D) Mixed radiolucent-radiopaque lesion with a ground-glass appearance
Answer: C
Rationale: Osteoradionecrosis typically presents as irregular radiolucency with sequestra and periosteal reaction
(option A). Option C describes aggressive features such as cortical erosion and soft tissue mass, which suggest
malignancy (e.g., radiation-induced sarcoma) and require biopsy. Option B is characteristic of a cemento-ossifying
fibroma, and option D suggests fibrous dysplasia.
13 A patient undergoing comprehensive treatment planning has a history of bisphosphonate therapy for
osteoporosis. The proposed treatment includes extraction of a periodontally hopeless mandibular molar. Which
of the following risk assessment strategies is most appropriate before proceeding?
A) Check serum calcium and parathyroid hormone levels to assess bone turnover
B) Obtain a panoramic radiograph to evaluate the extent of alveolar bone loss
C) Determine the duration of bisphosphonate therapy and consider a drug holiday of 3 months
D) Perform a cone-beam CT scan to measure cortical thickness and detect subperiosteal resorption
Answer: C
Rationale: The primary risk for medication-related osteonecrosis of the jaw (MRONJ) is the duration of
bisphosphonate therapy (>4 years) and the type of medication. A drug holiday of 3 months is often recommended
before invasive procedures to reduce risk, though evidence is debated. Serum calcium and PTH are not directly
relevant. Panoramic radiograph may show changes but is not a risk assessment tool. CBCT can evaluate existing
lesions but is not standard for risk assessment.
14 A patient presents with a painless, slowly enlarging swelling on the palate that crosses the midline. Computed
tomography reveals a well-defined, expansile, unilocular radiolucency with a thin, intact cortex. Incisional
biopsy shows a lining of non-keratinized stratified squamous epithelium with a fibrous connective tissue wall
containing chronic inflammatory cells and cholesterol clefts. Which of the following diagnoses is most
consistent, and what is the recommended definitive treatment?
A) Nasopalatine duct cyst; enucleation via palatal approach
B) Midline palatal cyst of the incisive canal; marsupialization
C) Surgical ciliated cyst of the palate; complete excision with curettage
D) Globulomaxillary cyst; enucleation and primary closure
Answer: A
Rationale: The nasopalatine duct cyst is the most common non-odontogenic cyst of the palate, often presenting as a
midline radiolucency. Histology shows non-keratinized stratified squamous epithelium with cholesterol clefts and
chronic inflammation. Enucleation is the treatment of choice. Marsupialization is less common for this cyst.
Surgical ciliated cyst is rare and usually lateral. Globulomaxillary cyst is now considered a fissural cyst, but it is
located between maxillary lateral incisor and canine, not midline.
15 In a patient with a history of intravenous drug use and hepatitis C, a routine dental examination reveals multiple
carious lesions and generalized moderate periodontitis. The patient reports no bleeding or bruising issues.
Laboratory results show platelet count of 60,000/mm³, INR of 1.2, and normal liver enzymes. Which of the
following modifications to the treatment plan is most appropriate?
A) Administer prophylactic platelet transfusion prior to any surgical procedure
B) Use local hemostatic agents and avoid inferior alveolar nerve block
C) Prescribe desmopressin 30 minutes before scaling and root planing
Answers - 150 Questions
Section 1: Diagnosis and Treatment Planning (Questions 1-15)
1 A patient presents with a solitary, painless, radiolucent lesion in the anterior mandible that appears unilocular on
panoramic radiograph. The lesion is non-expansile and asymptomatic. Which combination of diagnostic tests is
most appropriate to establish a definitive diagnosis before treatment planning?
A) Incisional biopsy and cone-beam computed tomography (CBCT)
B) Fine-needle aspiration and MRI
C) Excisional biopsy and periapical radiography
D) Sialography and ultrasound
Answer: A
Rationale: Incisional biopsy is required for histopathologic diagnosis of a radiolucent lesion, and CBCT provides
detailed cortical and spatial assessment, essential for surgical planning. Excisional biopsy is premature without
diagnosis. MRI is not indicated for this lesion, and sialography is for salivary glands.
2 A patient with a history of bisphosphonate therapy for osteoporosis presents with a non-healing extraction
socket and exposed bone. Which diagnostic step is most critical in determining the treatment plan?
A) Serum C-terminal telopeptide (CTX) level measurement
B) Panoramic radiography to assess bony sequestra
C) Microbial culture and sensitivity testing
D) Cone-beam computed tomography (CBCT) with contrast
Answer: A
Rationale: CTX level is a serum marker of bone turnover that helps stratify risk of medication-related osteonecrosis
of the jaw (MRONJ) and guides timing of surgical intervention. While radiography and culture are supportive,
CTX is the key diagnostic test for treatment planning in suspected MRONJ.
3 In a patient with chronic periodontitis and multiple missing teeth, which factor is most critical in determining
whether to recommend implants versus fixed partial dentures?
A) The patient's periodontal stability and compliance with maintenance
B) The number of missing teeth and arch location
C) The patient's age and gender
D) The presence of bruxism and parafunctional habits
Answer: A
Rationale: Periodontal stability and patient compliance are paramount because implant success depends on healthy
peri-implant tissues and long-term maintenance. While other factors influence the decision, uncontrolled
periodontitis is a contraindication for implants, making this the most critical factor.
4 A patient with a history of head and neck radiation therapy presents with xerostomia and rampant caries. Which
treatment planning approach is most appropriate to address the underlying etiology?
A) Prescribe high-fluoride toothpaste and chlorhexidine mouth rinse
B) Recommend salivary substitutes and regular fluoride varnish applications
C) Place full-coverage crowns on all affected teeth
D) Extract all non-restorable teeth and provide complete dentures
,Answer: B
Rationale: Salivary substitutes and fluoride varnish address the root cause (hyposalivation) and prevent further
caries. High-fluoride toothpaste is part of the regimen but not sufficient alone. Restorative treatment must be
preceded by caries control. Extractions are reserved for non-restorable teeth.
5 When developing a treatment plan for a patient with severe dental phobia and multiple carious lesions, which
sequence is most appropriate?
A) Begin with non-invasive preventive therapy, then use behavior management techniques, followed by
restorative care
B) Perform all restorative procedures under general anesthesia in one session
C) Start with extraction of non-restorable teeth, then schedule restorations
D) Refer to a psychologist before any dental treatment
Answer: A
Rationale: A phased approach that first addresses anxiety through behavior management and non-invasive treatment
builds trust and reduces fear. General anesthesia may be needed but is not the first-line approach. Extractions
without caries control can worsen anxiety. Psychological referral can be adjunctive but not prerequisite.
6 A patient presents with a painful, erythematous, and desquamative gingival lesion. Biopsy reveals subepithelial
clefting and a linear deposit of IgG along the basement membrane. Which systemic medication is most likely
indicated as part of the treatment plan?
A) Topical corticosteroids
B) Dapsone
C) Systemic corticosteroids
D) Tetracycline
Answer: C
Rationale: The histopathology and direct immunofluorescence are diagnostic of mucous membrane pemphigoid.
Systemic corticosteroids are the mainstay of treatment for moderate to severe cases. Topical corticosteroids are
used for mild disease. Dapsone is second-line, and tetracycline is not effective.
7 In a patient with a Class III malocclusion and significant facial asymmetry, which diagnostic record is most
essential for planning orthognathic surgery?
A) Cone-beam computed tomography (CBCT) with 3D cephalometric analysis
B) Lateral cephalometric radiograph with traditional analysis
C) Study models mounted on a semi-adjustable articulator
D) Facial photographs and intraoral scans
Answer: A
Rationale: CBCT with 3D cephalometric analysis provides comprehensive assessment of skeletal asymmetry,
airway, and temporomandibular joints, which is critical for surgical planning. Traditional 2D cephalometry is
limited in asymmetry cases. Articulator-mounted models are adjunctive but not primary for skeletal assessment.
8 A patient with a history of infective endocarditis requires dental treatment. Which of the following procedures
necessitates antibiotic prophylaxis according to current AHA guidelines?
A) Scaling and root planing in a patient with excellent oral hygiene
B) Restorative treatment with local anesthesia only
C) Placement of an orthodontic bracket
D) Taking dental radiographs
Answer: A
,Rationale: Scaling and root planing is a procedure that manipulates gingival tissue and may cause bacteremia,
requiring prophylaxis in high-risk patients. Restorative treatment without gingival manipulation, orthodontic
brackets, and radiographs do not require prophylaxis per current AHA guidelines.
9 A patient presents with a recurrent aphthous ulcer that has been present for 4 weeks and is larger than 1 cm. The
ulcer is painful and located on the soft palate. Which diagnostic consideration is most important in treatment
planning?
A) Rule out systemic diseases such as Behçet's disease or inflammatory bowel disease
B) Prescribe topical corticosteroids and reassess in 2 weeks
C) Obtain a biopsy to rule out malignancy
D) Order viral serology for herpes simplex virus
Answer: A
Rationale: The ulcer's size (>1 cm), duration (>4 weeks), and location (soft palate) are atypical for minor aphthous
ulcers and may indicate a major aphthous ulcer or systemic association. Behçet's disease and IBD are common
underlying conditions. Biopsy is indicated if malignancy is suspected, but systemic workup should precede. Topical
therapy is symptomatic but does not address etiology.
10 A patient with a history of cocaine use presents with a midline palatal perforation. Which diagnostic test is
most critical before surgical reconstruction?
A) Biopsy of the perforation margins
B) CT scan of the sinuses and nasal cavity
C) Serologic testing for syphilis
D) Urine toxicology screen
Answer: B
Rationale: CT scan is essential to evaluate the extent of bony destruction and involvement of adjacent structures
(sinuses, nasal cavity) for surgical planning. Biopsy may be needed to rule out other causes (e.g., malignancy,
granulomatosis with polyangiitis), but imaging is critical for reconstruction. Syphilis serology is part of the
differential but not the most critical for surgical planning. Toxicology confirms use but does not guide
reconstruction.
11 A patient presents with a well-defined radiolucency at the apex of tooth #9, which is non-responsive to cold and
electric pulp testing. The adjacent teeth are vital and the lesion is less than 1 cm in diameter. Radiographically,
the lesion appears as a unilocular radiolucency with a thin, sclerotic border. Which of the following diagnoses
is most consistent with these findings, and what is the recommended initial treatment approach?
A) Periapical granuloma; initiate nonsurgical root canal therapy
B) Radicular cyst; perform enucleation and apicoectomy
C) Periapical abscess; prescribe antibiotics and schedule extraction
D) Periapical scar; no treatment indicated, monitor radiographically
Answer: A
Rationale: The lesion is a well-defined radiolucency associated with a non-vital tooth, consistent with a periapical
granuloma (the most common periapical lesion). Radicular cysts are larger (>1 cm) and may show a thick sclerotic
border; however, this lesion is small. Periapical abscess would present with acute symptoms. Periapical scar is rare
and occurs after trauma. Nonsurgical root canal therapy is the first-line treatment for periapical granuloma.
12 In a patient with a history of head and neck radiation therapy for nasopharyngeal carcinoma, which of the
following findings on panoramic radiograph would most strongly indicate the need for a biopsy rather than
assuming osteoradionecrosis?
, A) Irregular, moth-eaten radiolucency with sequestra and periosteal reaction
B) Well-defined radiolucency with a sclerotic border and a central opacity
C) Diffuse, ill-defined radiolucency with cortical erosion and soft tissue mass
D) Mixed radiolucent-radiopaque lesion with a ground-glass appearance
Answer: C
Rationale: Osteoradionecrosis typically presents as irregular radiolucency with sequestra and periosteal reaction
(option A). Option C describes aggressive features such as cortical erosion and soft tissue mass, which suggest
malignancy (e.g., radiation-induced sarcoma) and require biopsy. Option B is characteristic of a cemento-ossifying
fibroma, and option D suggests fibrous dysplasia.
13 A patient undergoing comprehensive treatment planning has a history of bisphosphonate therapy for
osteoporosis. The proposed treatment includes extraction of a periodontally hopeless mandibular molar. Which
of the following risk assessment strategies is most appropriate before proceeding?
A) Check serum calcium and parathyroid hormone levels to assess bone turnover
B) Obtain a panoramic radiograph to evaluate the extent of alveolar bone loss
C) Determine the duration of bisphosphonate therapy and consider a drug holiday of 3 months
D) Perform a cone-beam CT scan to measure cortical thickness and detect subperiosteal resorption
Answer: C
Rationale: The primary risk for medication-related osteonecrosis of the jaw (MRONJ) is the duration of
bisphosphonate therapy (>4 years) and the type of medication. A drug holiday of 3 months is often recommended
before invasive procedures to reduce risk, though evidence is debated. Serum calcium and PTH are not directly
relevant. Panoramic radiograph may show changes but is not a risk assessment tool. CBCT can evaluate existing
lesions but is not standard for risk assessment.
14 A patient presents with a painless, slowly enlarging swelling on the palate that crosses the midline. Computed
tomography reveals a well-defined, expansile, unilocular radiolucency with a thin, intact cortex. Incisional
biopsy shows a lining of non-keratinized stratified squamous epithelium with a fibrous connective tissue wall
containing chronic inflammatory cells and cholesterol clefts. Which of the following diagnoses is most
consistent, and what is the recommended definitive treatment?
A) Nasopalatine duct cyst; enucleation via palatal approach
B) Midline palatal cyst of the incisive canal; marsupialization
C) Surgical ciliated cyst of the palate; complete excision with curettage
D) Globulomaxillary cyst; enucleation and primary closure
Answer: A
Rationale: The nasopalatine duct cyst is the most common non-odontogenic cyst of the palate, often presenting as a
midline radiolucency. Histology shows non-keratinized stratified squamous epithelium with cholesterol clefts and
chronic inflammation. Enucleation is the treatment of choice. Marsupialization is less common for this cyst.
Surgical ciliated cyst is rare and usually lateral. Globulomaxillary cyst is now considered a fissural cyst, but it is
located between maxillary lateral incisor and canine, not midline.
15 In a patient with a history of intravenous drug use and hepatitis C, a routine dental examination reveals multiple
carious lesions and generalized moderate periodontitis. The patient reports no bleeding or bruising issues.
Laboratory results show platelet count of 60,000/mm³, INR of 1.2, and normal liver enzymes. Which of the
following modifications to the treatment plan is most appropriate?
A) Administer prophylactic platelet transfusion prior to any surgical procedure
B) Use local hemostatic agents and avoid inferior alveolar nerve block
C) Prescribe desmopressin 30 minutes before scaling and root planing
