Exam questions & answers (Sample 11): Which one of the following is the most important property for dental cement to guarantee long term clinical success?



Download 45.36 Kb.
Date conversion29.01.2017
Size45.36 Kb.
Exam questions & answers (Sample 11):

1. Which ONE of the following is the most important property for dental cement to guarantee long term clinical success?
a. Compressive strength

b. Resistance to solubility and disintegration

c. Low coefficient of thermal expansion

d. Radiopacity similar to tooth structure

e. Setting contraction


2. Microleakage of bacterial endotoxins will result in:
a. Pulpal inflammation

b. Sensitivity

c. Cement dissolution

d. Loss of adhesion to dentin



3. Which one of the following is the reason that dental cement cannot be set by light curing methods alone?
a. Inadequate access

b. Oxygen inhibition of thin films

c. Excessive polymerization shrinkage

d. Visible light heating effects on the pulp

e. Dentin absorption in the visible light range
4. The overall reaction and properties of dental cements are most appropriately analyzed in terms of:
a. Non-crystalline ceramics

b. Non-crystalline polymers



c. Rule-of-mixtures for composites

d. Griffith-Orowan theory

e. Brannstrom theory
5. Which ONE of the following dental cements does NOT contain zinc oxide as part of its powder composition?
a. Zinc phosphate cement

b. Zinc silico-phosphate cement

c. ZOE cement

d. Durelon cement



e. Silicate cement

6. Which ONE of the following dental cements does NOT contain water as part of the composition of the liquid component?
a. Fleck's cement

b. IRM cement

c. Polycarboxylate cement

d. Tenacin cement

e. Geristore cement



7. Eugenol does NOT have which ONE of the following characteristics?
a. Oily liquid

b. Same composition as oil of cloves

c. Aromatic Odor

d. High reactivity toward ZnO

e. Obtundent effect on pulp



8. Phosphoric acid SOLUTIONS which are used as the liquid component of zinc phosphate and silico-phosphate cements have an INITIAL pH value of:
a. 0.1 to 1.0

b. 1.0 to 2.0

c. 2.0 to 3.0

d. 3.0 to 5.0

e. 5.0 to 7.0
9. Which of the cement powders for the following dental cements does NOT have a basic pH value?
a. ZOE cement

b. Zinc phosphate cement

c. Polycarboxylate cement

d. Silicate cement



e. None of the above
10. Which ONE of the following cements uses a liquid that is an aqueous solution of polymer?
a. Zinc phosphate cement

b. ZOE cement



c. Polycarboxylate cement

d. Silico-phosphate cement

e. ZOE reinforced cement
11. Which ONE of the following cements uses a liquid that is an aqueous solution of polymer?
a. Zinc phosphate cement

b. ZOE cement



c. Glass ionomer cement

d. Silicophosphate cement

e. ZOE reinforced cement
12. During the initial setting reaction for dental cements, approximately what percentage of powder is reacted?
a. 10 to 25%

b. 25 to 50%

c. 50 to 75%

d. 75 to 90%

e. 90 to 100%
13. Approximately what LEVEL of cement setting reaction is complete after the first hour?
a. 0-25%

b. 25-50%

c. 50-75%

d. 75-90%

e. 90-100%


14. What is the method of determining the SETTING TIME for dental cement reactions?
a. Peak exotherm of the reaction

b. Time interval to 150 psi strength



c. Large Gilmore needle

d. Loss of gloss

e. None of the above
15. The SETTING TIME is defined in which one of the following ways?
a. Elapsed time from the start of mixing to the completion of setting.

b. Elapsed time from the start of mixing to the start of setting.

c. The interval from the start of setting to the completion of setting.

d. The interval from the start of working to the completion of setting.

e. Elapsed time from the start of working to the completion of setting.
16. Which ONE of the following variables is VERY important for the mixing of ZOE cements?
a. Mixing temperature

b. Percent relative humidity

c. Mixing time

d. Method of spatulation

e. Method of powder addition


17. Which ONE of the following cements should be mixed on a chilled glass slab?
a. ZOE cement

b. ZOE reinforced cement

c. ZOE-EBA cement

d. Zinc phosphate cement

e. Polycarboxylate cement


18. Which ONE of the following cements should be mixed as quickly as possible?
a. Zinc phosphate cement

b. ZOE cement

c. ZOE-EBA cement

d. Silicophosphate cement



e. Polycarboxylate cement
19. Which ONE of the following cement mixtures is the least sensitive to temperature effects during mixing?
a. Polycarboxylate cement

b. ZOE cement

c. Zinc phosphate cement

d. Glass ionomer cement

e. Silicophosphate cement


20. For which ONE of the following dental cement types is the incremental addition of powder to the liquid extremely important during the mixing of the cement?
a. Dycal cement

b. Durelon cement



c. Tenacin cement

d. IRM cement

e. ZOE cement

21. Which ONE of the following dental cements requires catalysis for the setting to occur?
a. ZOE cement

b. Zinc phosphate cement

c. Silicophosphate cement

d. Polycarboxylate cement

e. Resin hybrid glass ionomer cement
22. Which ONE of the following dental cement phases is NOT CRYSTALLINE?
a. Zinc eugenolate

b. Tertiary zinc phosphate

c. Zinc oxide

d. Magnesium oxide



e. Zinc polyacrylate
23. The reaction product matrix of ZOE-EBA cement is primarily composed of:
a. Crystalline zinc eugenolate

b. Zinc ethoxybenzoate

c. Polymer reinforcement

d. Alumina

e. Zinc polyacrylate gel


24. EBA-HV cements do NOT contain which of the following:
a. Ethoxybenzoic acid

b. Hexylvanillate

c. Zinc oxide

d. Alumina



e. Eugenol
25. Which ONE of the following ZINC PHOSPHATE cement COMPONENTS primarily CONTROLS the reactivity of the powder and the liquid during mixing?
a. Zinc oxide powder particle size

b. Magnesium oxide additives

c. Aluminum phosphate buffers

d. Zinc phosphate buffers



e. Water content of the liquid
26. Which ONE of the following mixing methods is correct for zinc phosphate cement

manipulation?
a. 6 incremental additions of P over 90-120 sec with stropping on chilled glass slab.

b. 3 incremental additions of P over 90-120 sec using a chilled glass slab.

c. Rapid combination of all P into all L at the outset.

d. 3 incremental additions over 120 sec using a paper mixing pad.

e. None of the above.
27. Which ONE of the following methods is acceptable for retarding the

polycarboxylate cement reaction during mixing?
a. Use a chilled glass slab

b. Use chilled components

c. Add water to the liquid components

d. Decrease the powder-to-liquid ratio

e. Use incremental addition of powder to liquid


28. The setting reaction of IRM dental cement creates which ONE of the following reaction products in the matrix?
a. Zinc ethoxybenzoate

b. Zinc eugenolate

c. Tertiary zinc phosphate

d. Zinc polyacrylate gel

e. Calcium phosphate


29. The setting reaction of Fleck's Mizzy dental cement creates which ONE of the following reaction products in the matrix?
a. Zinc ethoxybenzoate

b. Zinc eugenolate



c. Tertiary zinc phosphate

d. Zinc polyacrylate gel

e. Calcium phosphate

30. Fluoride release from silicate cement involves:
a. Fluoride ion dissolution from particles and diffusion through the matrix

b. Fluoride uptake from saliva and re-release at other times

c. Hydrogen ion substitution from saliva for fluoride ion in the matrix

d. Visible light acceleration of ionization of components in residual powder

e. Precipitation of fluoride by calcium ions in saliva
31. The setting reaction of Durelon dental cement creates which ONE of the following reaction products in the matrix?
a. Zinc ethoxybenzoate

b. Zinc eugenolate

c. Tertiary zinc phosphate

d. Zinc polyacrylate gel

e. Calcium phosphate


32. Which one of the following acids have not been copolymerized into PCC liquid?
a. Acrylic acid

b. Maleic acid

c. Itaconic acid

d. Tartaric acid



e. Phthallic acid
33. Traditional glass ionomer cements are a hybrid of:
a. ZP and PCC

b. SC and SPC

c. ZOE-EBA and SC

d. SC and PCC

e. HV-EBA and ZP


34. The final reaction product matrix of GI cement is composed of:
a. Ca acrylate gel

b. Al acrylate gel

c. Tertiary zinc phosphate

d. Crystalline zinc ethoxybenzoate

e. BIS-GMA polymer


35. Fluoride is released from glass ionomer cement by:
a. Saliva reaction with residual glass particles

b. The same mechanism as silicate cement

c. Ion exchange reactions with matrix polymer

d. Secondary chemcial reactions of saliva with the matrix

e. Dissolution of fluoroapatite filler particles in the cement


36. Which one of the following is true of a resin hybrid GI?
a. Higher fluoride release

b. Lower compressive strength than traditional GI

c. Only light cured

d. Increased adhesion to dentin



e. Higher coefficient of thermal expansion
37. Which ONE of the following is a key example of reinforced ZOE?
a. IRM

b. Fleck's

c. Durelon

d. Geristore

e. Dycal
38. Which ONE of the following is a key example of PCC?
a. IRM

b. Fleck's



c. Durelon

d. Geristore

e. Dycal
39. Which ONE of the following is a key example of a resin hybrid GI?
a. IRM

b. Fleck's

c. Durelon

d. Geristore

e. Dycal
40. Which ONE(S) of the following properties of dental cements is(are) affected by the P/L ratio?


a. Dimensional change on setting

b. Intraoral solubility

c. Compressive strength

d. Thermal conductivity



e. All of the above
41. Which ONE of the following is the predominant reason for early clinical failure of dental cements?
a. Improper choice of commercially competitive products

b. Improper mixing and/or manipulation of materials

c. Inadequate cement strength



d. Inadequate solubility resistance

e. All of the above


The database is protected by copyright ©dentisty.org 2016
send message

    Main page