INBDE Cariology & Operative Dentistry practice questions

Question 1

A 22-year-old patient presents with a deep carious lesion on the occlusal surface of tooth #19. Radiographically, the decay is close to the pulp, but there is a 1.0 mm thickness of remaining dentin (RDT) and no history of spontaneous pain. Which pulp protection protocol is most appropriate before placing a composite restoration?

Accepted Answer

Resin-Modified Glass Ionomer (RMGI) base only

Answer

Calcium hydroxide liner followed by Resin-Modified Glass Ionomer (RMGI) base

Answer

Zinc Oxide Eugenol (ZOE) base

Answer

No liner or base; direct application of bonding agent and composite

Question 2

During a dietary analysis, a dentist explains to a patient that the critical pH at which enamel hydroxyapatite begins to demineralize is approximately 5.5. How does the incorporation of fluoride into the enamel surface change this process?

Accepted Answer

It lowers the critical pH to approximately 4.5, making the tooth more resistant to acid.

Answer

It raises the critical pH to 6.7, making demineralization happen sooner.

Answer

It increases the solubility of the enamel crystals in the presence of lactic acid.

Answer

It prevents the diffusion of calcium and phosphate ions out of the enamel entirely.

Question 3

A practitioner is preparing a narrow, deep Class I occlusal cavity for a composite resin. Which of the following statements regarding the 'C-factor' for this preparation is most accurate?

Accepted Answer

The C-factor is high (5), increasing the risk of bond failure and marginal leakage.

Answer

The C-factor is low (0.2), resulting in minimal polymerization stress.

Answer

The C-factor is high (5), which helps the composite adapt better to the walls.

Answer

The C-factor is low (1), as only the pulpal floor is a bonded surface.

Question 4

Glass ionomer restoratives bond to tooth structure through which primary mechanism?

Accepted Answer

Chemical chelation between carboxyl groups of the polyacrylic acid and calcium in the tooth

Answer

Micromechanical interlocking into acid-etched enamel rods

Answer

Covalent bonding to the organic collagen matrix of the dentin

Answer

Purely physical adhesion through van der Waals forces

Question 5

A patient presents with a lesion on the cusp tip of tooth #5 and the incisal edge of #8, but nowhere else. According to Black's Classification of cavities, these are categorized as:

Accepted Answer

Class VI

Answer

Class IV

Answer

Class V

Answer

Class I

Question 6

When comparing the Coefficient of Thermal Expansion (CTE) of dental materials to human enamel and dentin, which of the following is true?

Accepted Answer

Composite resin has a CTE 2 to 3 times higher than tooth structure.

Answer

Amalgam has a CTE nearly identical to tooth structure.

Answer

Unfilled resins have a lower CTE than tooth structure.

Answer

Glass ionomer has the highest CTE of all restorative materials.

Question 7

Fluoride is known to have an antibacterial effect. Which specific bacterial enzyme is inhibited by fluoride, thereby disrupting glycolysis?

Accepted Answer

Enolase

Answer

Glucosyltransferase

Answer

Lactate dehydrogenase

Answer

Dextransucrase

Question 8

In a deep carious lesion where a small (less than 1mm) mechanical exposure of the pulp occurs in a tooth with no prior symptoms, a direct pulp cap is performed. Which material is considered the gold standard for this procedure due to its superior sealing and dentin bridge formation?

Accepted Answer

Mineral Trioxide Aggregate (MTA)

Answer

Zinc Phosphate cement

Answer

Resin-modified glass ionomer

Answer

Bonding agent and flowable composite

Question 9

A dentist is using a 6th-generation 'self-etch' adhesive system. Which of the following best describes the management of the smear layer with this system?

Accepted Answer

The smear layer is modified and incorporated into the hybrid layer.

Answer

The smear layer is completely removed by 37% phosphoric acid.

Answer

The smear layer is rinsed away with a water-air spray prior to priming.

Answer

The smear layer is thickened to improve bond strength to the dentin.

Question 10

When preparing a Class II cavity for dental amalgam, the 'resistance form' is primarily achieved by which of the following features?

Accepted Answer

Creating a flat pulpal floor and rounded internal line angles.

Answer

Placing occlusal dovetails to prevent proximal displacement.

Answer

Creating convergent buccal and lingual walls.

Answer

Adding retentive grooves in the axio-buccal and axio-lingual line angles.

INBDE Cariology & Operative Dentistry practice questions

During a dietary analysis, a dentist explains to a patient that the critical pH at which enamel hydroxyapatite begins to demineralize is approximately 5.5. How does the incorporation of fluoride into the enamel surface change this process?

A practitioner is preparing a narrow, deep Class I occlusal cavity for a composite resin. Which of the following statements regarding the 'C-factor' for this preparation is most accurate?

Glass ionomer restoratives bond to tooth structure through which primary mechanism?

A patient presents with a lesion on the cusp tip of tooth #5 and the incisal edge of #8, but nowhere else. According to Black's Classification of cavities, these are categorized as:

When comparing the Coefficient of Thermal Expansion (CTE) of dental materials to human enamel and dentin, which of the following is true?

Fluoride is known to have an antibacterial effect. Which specific bacterial enzyme is inhibited by fluoride, thereby disrupting glycolysis?

In a deep carious lesion where a small (less than 1mm) mechanical exposure of the pulp occurs in a tooth with no prior symptoms, a direct pulp cap is performed. Which material is considered the gold standard for this procedure due to its superior sealing and dentin bridge formation?

A dentist is using a 6th-generation 'self-etch' adhesive system. Which of the following best describes the management of the smear layer with this system?

When preparing a Class II cavity for dental amalgam, the 'resistance form' is primarily achieved by which of the following features?

The first 10 are free. 6 more below.

Which property of dental amalgam is responsible for its long-term success in sealing margins even if the initial adaptation was imperfect?

A 45-year-old patient requires a Class II composite restoration on tooth #3. To ensure an anatomically correct proximal contact and minimize food impaction, which matrix system is most recommended?

What is the primary reason for performing an indirect pulp cap rather than completing a full caries excavation that would likely result in pulpal exposure?

A patient presents with 'white spot lesions' on the cervical thirds of several maxillary teeth. If these lesions are smooth and shiny upon drying, what is the most likely clinical interpretation?

Which of the following describes the 'hybrid layer' in dentin bonding?

A 10-year-old child lives in an area with non-fluoridated water. The dentist prescribes a fluoride supplement. What is the most important mechanism of systemic fluoride before the teeth erupt?