ABE Endodontic Materials 3

Question 1

EDTA is used as an endodontic irrigant primarily for its ability to:

Accepted Answer

Remove the smear layer by chelating calcium from dentin

Answer

Kill anaerobic bacteria in the root canal

Answer

Dissolve pulp tissue remnants

Answer

Bleach intrinsically stained dentin

Question 2

The working length of a nickel-titanium rotary file is typically confirmed using:

Accepted Answer

Electronic apex locators and radiographic confirmation

Answer

Periapical radiographs alone

Answer

Tactile sensation only

Answer

Cone beam CT scan

Question 3

Which irrigant is most effective at dissolving necrotic pulp tissue in the root canal?

Accepted Answer

Sodium hypochlorite 5.25%

Answer

Chlorhexidine 2%

Answer

EDTA 17%

Answer

Citric acid 10%

Question 4

Biodentine differs from ProRoot MTA primarily in its:

Accepted Answer

Much faster setting time due to calcium chloride accelerator

Answer

Calcium silicate chemistry

Answer

Biocompatibility with periapical tissues

Answer

Ability to set in a moist environment

Question 5

The alpha phase of gutta-percha differs from the beta phase in that it:

Accepted Answer

Is found in the naturally occurring form in the Palaquium tree

Answer

Is used for thermoplastic obturation techniques

Answer

Has a lower melting point and greater brittleness

Answer

Contains a higher percentage of zinc oxide filler

Question 6

When mixing zinc oxide eugenol cement for an interim restoration, increasing the powder-to-liquid ratio will result in:

Accepted Answer

Shorter setting time and increased compressive strength

Answer

Longer working time and decreased strength

Answer

Increased eugenol release and cytotoxicity

Answer

No change in setting time but reduced viscosity

Question 7

The primary function of the smear layer removal protocol (NaOCl followed by EDTA) in endodontics is to:

Accepted Answer

Improve sealer penetration into dentinal tubules

Answer

Increase the pH of the root canal system

Answer

Eliminate all biofilm from the root canal

Answer

Prevent post-operative pain after obturation