NDEB Study Guide 2026
Everything you need to pass the NDEB exam in one place: the exam format, every topic to study, real practice questions with explanations, flashcards, and full-length practice tests. Free, no sign-up needed.
📋 NDEB Exam Format at a Glance
📚 NDEB Topics to Study (21)
✍️ Sample NDEB Questions & Answers
1. In a child with Turner tooth (enamel hypoplasia of a permanent tooth), what is the most likely cause?
Turner tooth results from periapical infection or trauma to the primary predecessor tooth disrupting enamel formation of the developing permanent tooth.
2. Overjet is defined as:
Overjet is the horizontal (sagittal) distance measured from the labial surface of the mandibular central incisor to the labial surface of the maxillary central incisor.
3. Surface enamel is more highly mineralized than the rest of the enamel because _______:
Explanation: Surface enamel is more highly mineralized than the rest of the enamel because the crystallites are deposited parallel to the surface, resulting in greater mineral density and hardness.
4. A patient with a known allergy to ester-type local anesthetics requires a maxillary infiltration for a restorative procedure. Which of the following local anesthetic agents would be the safest to use?
Lidocaine is an amide-type local anesthetic. Allergies to local anesthetics are more common with the ester class due to their metabolism to para-aminobenzoic acid (PABA). A true allergy to one ester-type anesthetic generally contraindicates the use of all other ester anesthetics (like procaine and tetracaine). While benzocaine is an ester, an allergy to one amide does not rule out the use of another amide, making lidocaine a safe choice in this scenario.
5. Which of the following occlusal schemes is most frequently recommended for complete dentures to enhance stability during parafunctional movements and accommodate patients with resorbed ridges?
Lingualized occlusion is an occlusal scheme where the maxillary lingual cusps articulate with the central fossae of the mandibular teeth. This setup centralizes occlusal forces, minimizes tipping forces, and provides bilateral balance, which is highly advantageous for denture stability, especially in patients with significant ridge resorption. Canine guidance and group function are concepts primarily applied to natural dentition and fixed prosthodontics and can create destabilizing forces in complete dentures.
6. Which bacteria is most associated with the initiation of dental caries?
Streptococcus mutans is the primary cariogenic bacterium, producing lactic acid and colonizing smooth tooth surfaces to initiate decay.