FREE AGD Operative and Restorative Dentistry Questions and Answers

Question 1

A dentist prepares a conservative, deep Class I occlusal cavity on a mandibular molar for a composite restoration.
What is the primary clinical challenge associated with the high configuration factor (C-Factor) of this preparation?

Accepted Answer

Increased polymerization shrinkage stress on the bonded interfaces.

Answer

Difficulty achieving adequate light polymerization at the pulpal floor.

Answer

Poor wetting of the cavity walls by the adhesive agent.

Answer

Inability to create a well-defined hybrid layer in the deep dentin.

Question 2

A patient presents with a deep carious lesion on tooth #14, approaching the pulp. After caries excavation, you decide to place a liner before the final composite restoration. Which of the following is a primary advantage of using a resin-modified glass ionomer (RMGI) for this purpose?

Accepted Answer

It provides sustained fluoride release and forms a true chemical bond to the tooth structure.

Answer

It provides the highest immediate bond strength to dentin compared to any other material.

Answer

It has a coefficient of thermal expansion identical to that of composite resin.

Answer

It is completely insoluble and resistant to acid degradation from microleakage.

Question 3

When preparing a maxillary molar for a lithium disilicate ceramic onlay that will cover two cusps, which of the following preparation features is most critical for ensuring the long-term fracture resistance of the restoration?

Accepted Answer

Broad, rounded internal line angles and adequate occlusal thickness.

Answer

Axial walls with a minimal taper of 2-4 degrees.

Answer

A sharp, well-defined gingival bevel.

Answer

A deep retentive groove placed at the axio-pulpal line angle.

Question 4

During the application of a total-etch (etch-and-rinse) adhesive system, what is the most significant negative consequence of aggressively air-drying the dentin after the acid-etching and rinsing step?

Accepted Answer

It causes the collapse of the exposed collagen fibril network, preventing hybrid layer formation.

Answer

It prevents the complete removal of the smear layer.

Answer

It hyper-mineralizes the dentin surface, inhibiting resin infiltration.

Answer

It increases the risk of post-operative thermal sensitivity due to open tubules.

Question 5

Which of the following is the primary mechanism by which Silver Diamine Fluoride (SDF) arrests active carious lesions?

Accepted Answer

Forming a silver-protein conjugate that is resistant to acid and enzymatic degradation.

Answer

Stimulating the odontoblasts to form reparative tertiary dentin.

Answer

Creating a hypermineralized layer of fluorapatite that is 10 times harder than hydroxyapatite.

Answer

Physically sealing the dentinal tubules with a glass-like material.

Question 6

A patient calls your office one week after you placed a moderately deep Class II MO composite on tooth #29. They report a sharp, brief pain only when they chew on something hard in that area. The pain disappears immediately upon release. The occlusion was checked and feels fine. What is the most probable cause?

Accepted Answer

A small marginal gap or void at the gingival floor of the preparation.

Answer

An air bubble trapped within the bulk of the composite material.

Answer

A premature contact on the marginal ridge in lateral excursive movements.

Answer

A delayed hypersensitivity reaction to the BIS-GMA resin.