100+ Free INBDE Practice Questions

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In ideal Class I molar occlusion, the mesiobuccal cusp of the maxillary first molar occludes with:

The mesiobuccal groove of the mandibular first molar

The central fossa of the mandibular first molar

The mesial marginal ridge of the mandibular second premolar

The distal fossa of the mandibular first molar

to track

2026 Statistics

Key Facts: INBDE Exam

99%+

CODA Student Pass Rate

JCNDE Data

Passing Score

On 49-99 scale

300-500 hrs

Study Time

Recommended

$170,910

Median Dentist Salary

BLS 2024

500

Total Questions

Over 2 days

$890

Exam Fee

JCNDE 2026

The INBDE (Integrated National Board Dental Examination) replaced NBDE Parts I and II as the single national dental licensing exam. It consists of 500 multiple-choice questions administered over 2 days. A scaled score of 75/99 is required to pass. First-attempt pass rates exceed 99% for CODA-accredited students but are 65-75% for international graduates. The exam covers 56 Clinical Content areas and 10 Foundation Knowledge areas. The exam fee is $890 ($1,325 for non-CODA candidates). The median salary for general dentists is $170,910 (BLS 2024).

Sample INBDE Practice Questions

Try these sample questions to test your INBDE exam readiness. Each question includes a detailed explanation. Start the interactive quiz above for the full 100+ question experience with AI tutoring.

1Which cranial nerve provides sensory innervation to the maxillary teeth?

A.Trigeminal nerve (CN V) — maxillary division (V2)

B.Facial nerve (CN VII)

C.Glossopharyngeal nerve (CN IX)

D.Hypoglossal nerve (CN XII)

Explanation: The maxillary division (V2) of the trigeminal nerve provides sensory innervation to the maxillary teeth via the posterior, middle, and anterior superior alveolar nerves. Understanding the branches of CN V is essential for administering dental anesthesia. INBDE tip: Know all three divisions of the trigeminal nerve and their clinical significance.

2The parotid gland duct (Stensen's duct) opens into the oral cavity opposite which tooth?

A.Maxillary first molar

B.Maxillary second premolar

C.Mandibular first molar

D.Mandibular second premolar

Explanation: Stensen's duct (parotid duct) opens into the oral cavity through the buccal mucosa opposite the maxillary second premolar. This is clinically significant when examining for salivary gland pathology or placing intraoral devices. INBDE tip: Know the locations of all major salivary gland duct openings.

3During the bell stage of tooth development, which cells differentiate into ameloblasts?

A.Cells of the outer enamel epithelium

B.Cells of the inner enamel epithelium

C.Cells of the dental papilla

D.Cells of the dental follicle

Explanation: During the bell stage, cells of the inner enamel epithelium differentiate into ameloblasts, which are responsible for enamel formation. The dental papilla gives rise to odontoblasts (dentin formation), and the dental follicle forms the periodontal ligament, cementum, and alveolar bone. Understanding tooth development stages is heavily tested on the INBDE.

4Which muscle is the primary elevator of the mandible during mastication?

A.Lateral pterygoid

B.Masseter

C.Digastric

D.Buccinator

Explanation: The masseter is the primary elevator of the mandible and is the strongest muscle of mastication. The temporalis and medial pterygoid also elevate the mandible. The lateral pterygoid is involved in protrusion and opening, the digastric depresses the mandible, and the buccinator assists in keeping food between the teeth during chewing.

5A patient presents with a lesion on the lateral border of the tongue. Which lymph nodes would be the first to receive drainage from this area?

A.Submental lymph nodes

B.Submandibular lymph nodes

C.Deep cervical lymph nodes

D.Parotid lymph nodes

Explanation: The lateral border of the tongue drains primarily to the submandibular lymph nodes. The tip of the tongue drains to submental nodes, and the posterior third drains to deep cervical nodes. Knowledge of lymphatic drainage is critical for staging oral cancers and understanding metastatic patterns.

6Which enzyme initiates the digestion of starch in the oral cavity?

A.Pepsin

B.Salivary amylase (ptyalin)

C.Lipase

D.Trypsin

Explanation: Salivary amylase (ptyalin) is secreted by the serous cells of the salivary glands and initiates the digestion of starch by breaking down alpha-1,4-glycosidic bonds to produce maltose and dextrins. Its optimal pH is 6.8. Pepsin works in the stomach, trypsin in the small intestine, and lipase breaks down fats.

7Fluoride's primary mechanism for preventing dental caries involves:

A.Killing all bacteria in the oral cavity

B.Enhancing remineralization and forming fluorapatite, which is more resistant to acid dissolution

C.Increasing salivary flow rate

D.Blocking sugar absorption by enamel

Explanation: Fluoride prevents caries primarily by enhancing remineralization of demineralized enamel and forming fluorapatite, which is more resistant to acid dissolution than hydroxyapatite. Fluoride also inhibits bacterial metabolism and reduces acid production. It does not kill all bacteria or block sugar absorption. INBDE tip: Understand both systemic and topical mechanisms of fluoride.

8Which of the following vitamins is essential for collagen synthesis and deficiency leads to scurvy with gingival manifestations?

A.Vitamin A

B.Vitamin B12

C.Vitamin C

D.Vitamin D

Explanation: Vitamin C (ascorbic acid) is essential for collagen synthesis as a cofactor for prolyl hydroxylase and lysyl hydroxylase. Deficiency leads to scurvy, characterized by impaired collagen formation, resulting in gingival bleeding, swollen gums, tooth loosening, and poor wound healing. INBDE tip: Link vitamin deficiencies to their oral manifestations.

9The Krebs cycle (citric acid cycle) takes place in which cellular compartment?

A.Cytoplasm

B.Mitochondrial matrix

C.Endoplasmic reticulum

D.Cell nucleus

Explanation: The Krebs cycle occurs in the mitochondrial matrix, where acetyl-CoA is oxidized to CO2, generating NADH, FADH2, and GTP. Glycolysis occurs in the cytoplasm, and the electron transport chain occurs in the inner mitochondrial membrane. Understanding cellular metabolism is foundational for INBDE biochemistry questions.

10A patient with uncontrolled diabetes mellitus is at increased risk for which of the following oral conditions?

A.Enamel hypoplasia

B.Periodontal disease with accelerated bone loss

C.Dental fluorosis

D.Amelogenesis imperfecta

Explanation: Patients with uncontrolled diabetes mellitus have an increased risk of periodontal disease with accelerated alveolar bone loss. Hyperglycemia impairs neutrophil function, increases collagenase activity, promotes formation of advanced glycation end products (AGEs), and disrupts the host immune response. Periodontal disease is considered the sixth complication of diabetes.

About the INBDE Exam

The INBDE is the comprehensive dental licensing exam that replaced NBDE Parts I and II. With 500 questions over 2 days, it integrates biomedical sciences with clinical dentistry. CODA-accredited program students have a 99%+ first-attempt pass rate, but the exam demands thorough preparation across all dental disciplines.

Questions

500 scored questions

Time Limit

2 days (12 hours 30 minutes total)

Passing Score

75 (on a 49-99 scale)

Exam Fee

$890 (JCNDE (ADA))

INBDE Exam Content Outline

30%

Diagnosis and Treatment Planning

Patient assessment, radiographs, treatment sequencing, risk assessment, prognosis

40%

Oral Health Management

Restorative, endodontics, periodontics, prosthodontics, oral surgery, orthodontics, pediatrics

10%

Practice and Profession

Ethics, infection control, radiation safety, evidence-based dentistry, HIPAA

10%

Foundation Knowledge — Biomedical Sciences

Anatomy, biochemistry, physiology, microbiology, pathology, pharmacology

10%

Foundation Knowledge — Dental Sciences

Dental anatomy, occlusion, dental materials, biomechanics

How to Pass the INBDE Exam

What You Need to Know

Passing score: 75 (on a 49-99 scale)
Exam length: 500 questions
Time limit: 2 days (12 hours 30 minutes total)
Exam fee: $890

Keys to Passing

Complete 500+ practice questions
Score 80%+ consistently before scheduling
Focus on highest-weighted sections
Use our AI tutor for tough concepts

INBDE Study Tips from Top Performers

1Focus on Oral Health Management (40% of exam) — master restorative, endodontics, periodontics, and prosthodontics first

2Study case-based questions that integrate multiple disciplines, mimicking the actual INBDE format

3Know your pharmacology cold — drug interactions, maximum doses of local anesthetics, and antibiotic prophylaxis guidelines

4Complete at least 3,000 practice questions and track your performance by topic area

5Use our AI tutor to work through clinical scenarios and understand the reasoning behind treatment decisions

Frequently Asked Questions

What is the INBDE pass rate?

The INBDE has a 99%+ first-attempt pass rate for students from CODA-accredited dental programs (only 0.8-1.3% fail rate). However, international dental graduates face a more challenging 65-75% pass rate. The exam uses a scaled score of 49-99, with 75 as the minimum passing score. With comprehensive preparation, you can join the vast majority who pass on their first attempt.

How is the INBDE different from the old NBDE?

The INBDE replaced NBDE Parts I and II with a single integrated exam. Unlike the separate basic science (Part I) and clinical science (Part II) format, the INBDE integrates biomedical and clinical knowledge in every question. It uses more case-based and patient-centered questions, emphasizing clinical application rather than rote memorization of isolated facts.

How many questions are on the INBDE?

The INBDE has 500 multiple-choice questions administered over 2 days. Not all questions are scored — some are experimental pretest questions used to evaluate items for future exams. The exam includes both standalone questions and case-based question sets with dental charts and patient information. Total testing time is 12 hours and 30 minutes including breaks.

What topics are tested on the INBDE?

The INBDE covers 56 Clinical Content areas grouped into Diagnosis & Treatment Planning (30%), Oral Health Management (40%), and Practice & Profession (10%), plus 10 Foundation Knowledge areas in Biomedical Sciences (10%) and Dental Sciences (10%). The highest-yield topics include restorative, endodontics, periodontics, pharmacology, and oral pathology.

How long should I study for the INBDE?

Plan for 300-500 hours of study over 3-6 months while in dental school. Most students begin focused preparation 3-4 months before the exam. Allocate 40% of study time to clinical sciences, 30% to diagnosis/treatment planning, 20% to biomedical foundations, and 10% to practice/profession topics. Complete at least 3,000 practice questions.

Can international dental graduates take the INBDE?

Yes, international dental graduates can take the INBDE. They must have their educational credentials evaluated by ECE (Educational Credential Evaluators), pay an additional $435 processing fee (total $1,325), and obtain a Certification of Eligibility Form. Many international graduates also enroll in Advanced Standing Programs at CODA-accredited schools to strengthen their preparation.

What is the career outlook for dentists?

The BLS projects 4% employment growth for dentists from 2023-2033, with approximately 5,100 job openings per year. The median annual salary for general dentists is $170,910 (BLS 2024), with specialists earning significantly more. There are approximately 162,000 dentist jobs in the U.S., and demand continues to grow as the population ages.