ABE Endodontic Materials 2

Question 1

Which property of mineral trioxide aggregate (MTA) makes it particularly suitable as a perforation repair material?

Accepted Answer

Excellent biocompatibility and sealing ability in the presence of moisture

Answer

MTA's biocompatibility, ability to set in moisture, and superior marginal seal make it ideal for perforation repair.

Question 2

The International Organization for Standardization (ISO) specification for gutta-percha points requires the taper of standardized cones to be:

Accepted Answer

0.02 mm/mm

Answer

ISO specification 6877 requires standardized gutta-percha cones to have a 0.02 mm/mm taper matching standardized instruments.

Question 3

Calcium hydroxide exerts its antimicrobial effect primarily through:

Accepted Answer

High pH causing protein denaturation and enzyme disruption

Answer

Calcium hydroxide's pH of approximately 12.5 causes protein denaturation and disrupts enzyme activity in bacterial cells.

Question 4

Which endodontic sealer has the lowest shrinkage upon setting among the following options?

Accepted Answer

Resin-based sealers (AH Plus)

Answer

AH Plus epoxy resin sealer exhibits minimal volumetric shrinkage upon polymerization compared to other sealer types.

Question 5

The solvent most commonly used to dissolve gutta-percha during retreatment is:

Accepted Answer

Chloroform

Answer

Chloroform is the most effective solvent for dissolving gutta-percha, though its use is restricted in some countries due to carcinogenicity concerns.

(ABE) American Board of Endodontics Practice Test