This forum made possible through the generous support of SDN members, donors, and sponsors. Thank you.


7+ Year Member
Oct 17, 2015
Reaction score
Hello Guys!

I am doing NBDE exam soon and would like to share and discuss questions here.

Anyone is welcome to share their knowledge and post their own questions they doubt.

I will start with few questions now, hopefully we can learn from each other.

Starting with operative now!

Dental amalgams that are made from alloys containing 6 percent copper, compared to those made from alloys containing 13 percent copper

1. have higher concentration of the tin-mercury phase.

2. are more resistant to tarnish and corrosion.

3. demonstrate less creep or flow.

4. generally have lower compressive strength.

5. demonstrate less marginal breakdown in clinical service.

A. (1) (3) (4)

B. (2) (3) (5)

C. (1) and (2)

D. (4) and (5)

E. (1) and (4) .
My ans C

Which of the following would occur if a zinc containing amalgam is contaminated with saliva during condensing?

1. No change in compressive strength but lower tensile strength.

2. Increased expansion.

3. Reduced flow or creep.

4. Increased surface pitting.

A. (1) (2) (3)

B. (1) and (3)

C. (2) and (4)

D. (4) only

E. All of the above.
My ans C. Zine causes delayed expansion, do you think its different than exapnsion as a single term and by that would you choose D.

In cementing a full crown, it is desirable to

A. ****** the set of the cement.

B. apply continuous occlusal loading.

C. have excess cement covering the margins.

D. All of the above.
My ans A theres a lot of debate and controversy of this question!!!

The presence of tin in an amalgam alloy modifies the reaction and physical properties of the amalgam in that it

A. speeds the amalgamation rate.

B. enhances strength.

C. enhances tarnish resistance.

D. reduces flow. .
My ans C

Afterr initial setting, a chemically cured glass ionomer cement restoration should have a coating agent applied to

A. hasten the final set.

B. protect the cement from moisture.

C. ****** the final set.

D. protect the cement from ultraviolet light.

E. create a smooth finish.
My ans B

I need help with these questions, any takers? Bring on your logic and your questions too!

Members don't see this ad.