FREE NBDE Ultimate Questions and Answers

Question 1

A patient presents with a white lesions on his buccal mucosa. The lesion is 4mm x 4mm in size and has been present in the patient's mouth for 4 months. Last week it became ulcerated and prompted the patient to see you. What would appropriate management entail?

Accepted Answer

Excisional biopsy

Answer

A white lesion that has been present for 4 months and recently became ulcerated is suspicious for malignancy or a significant pathology. Given its relatively small size (4x4mm), an excisional biopsy is appropriate to completely remove the lesion for definitive diagnosis and simultaneously treat it if benign. This approach provides the most comprehensive diagnostic and therapeutic benefit for suspicious, small lesions.

Question 2

A patients presents with a mandibular first molar that has a failing root canal. Recurrent decay underneath the crown has caused severe damage to the remaining tooth structure and re-infection of the root canal space. Due to remove the tooth.  What nerves would need to be blocked for surgical removal of this tooth?

Accepted Answer

Inferior alveolar, lingual, long buccal

Answer

To extract a mandibular first molar, the inferior alveolar nerve needs to be blocked for pulpal and buccal bone anesthesia. The lingual nerve needs to be blocked for lingual soft tissue anesthesia. Additionally, the long buccal nerve (also known as the buccal nerve) needs to be blocked to anesthetize the buccal soft tissue and periosteum in the molar region, ensuring complete pain control during the procedure.

Question 3

Of the following root fracture possibilities, which has the WORST prognosis?

Accepted Answer

Mobile vertical fracture

Answer

Vertical root fractures, especially when mobile, have the worst prognosis because they often involve the entire length of the root, leading to bacterial contamination of the periodontal ligament and bone. They are difficult to treat and often result in extraction due to irreparable damage and persistent infection. Horizontal fractures generally have a better prognosis, especially if apical or mid-root and non-mobile.

Question 4

You are performing endodontic therapy on an upper first molar, and a file is broken in the distobuccal canal. On radiograph, you discover the fragment is 2.5mm long and is wedged tightly in the apical portion of the root, but not extruding past the foramen. What should you do?

Accepted Answer

Inform the patient, complete the procedure and monitor

Answer

If a file fragment is broken in the apical portion of a canal, is tightly wedged, and not extruded, the best course of action is often to inform the patient, complete the root canal procedure to the level of the fragment, and then monitor the tooth. Attempting to retrieve a tightly wedged, non-extruded fragment can cause more damage (e.g., perforation, further extrusion) and many teeth with retained fragments remain asymptomatic and functional.

Question 5

In adolescents, when minor fractures occur to the permanent teeth, it is prudent to use which type of restoration?

Accepted Answer

Composite resin restorations

Answer

Composite resin restorations are the preferred choice for minor fractures in permanent teeth of adolescents due to their conservative nature and excellent aesthetics. They bond directly to the tooth structure, preserving maximum natural tooth tissue, which is crucial for young permanent teeth that may still have large pulp chambers. Other options like full crowns are more aggressive, and amalgam is less aesthetic.

NBDE - National Board Dental Examination Practice Test

NBDE - National Board Dental Examination Practice Test

FREE NBDE Ultimate Questions and Answers