Final Questions Flashcards
Pre-carve burnishing produces denser amalgam at the restoration margins.
True
False
true (Amalgam slide 52)
How many degrees do walls converge or diverge in cavity preparations?
a. 2-3.
b. 3-4.
c. 9-10.
d. 5-7.
5-7
In which area of the tooth do the enamel rods orient themselves apically as they progress from the DEJ to the external tooth surface? Cusp tips. Developmental grooves. Cervical. No enamel rods orient apically.
Cervical
By definition dental amalgam is alloy combined with: Silver Tin Copper Mercury
Mercury
Inhaling mercury vapor can be a health hazard to the dental team because
a. While in the unionized state on blood it can bind to kidney enzymes,reducing the ability of the kidneys to excrete other compounds
b. While in the unionized state it can cross the blood-brain barrier, but when it subsequently becomes ionized it is much less able to do so
c. While in the ionized state it cannot be excreted by the kidneys, so it tends to accumulate in all body tissues and decrease enzyme function
While in the unionized state it can cross the blood-brain barrier, but when it subsequently becomes ionized it is much less able to do so
Dentin is: Formed by ameloblasts. More mineralized than enamel. Capable of self repair. Less permeable than enamel.
Capable of self repair
Identify the primary elements present in each of the following phases of dental amalgam.
- Gamma
- Gamma I
- Gamma II
- Eta
- Gamma _ Ag3Sn
- Gamma I _ Ag2Hg3
- Gamma II _ Sn8Hg
- Eta _ Cu6Sn5
Lactobacilli dominate during the _____of caries.
Onset. (strep. mutans)
Progression.
progression
Once caries reaches the DEJ, it spreads laterally and pulpally.
a. True.
b. False.
true
In explaining the risks of mercury toxicity, it is useful to begin by making the distinction between the three forms of mercury. Which of the following best describes the three forms?
a. Methyl mercury, ethyl mercury, iso-propyl mercury.
b. Elemental; inorganic compounds; organic compounds.
c. Solid mercury; liquid mercury; mercury vapor.
d. Gamma 1, gamma 2, gamma 3
Elemental; inorganic compounds; organic compounds.
What is the GREATEST hazard for mercury toxicity in the dental office? Mercury spills. Mercury vapor inhalation. Skin contact with mercury. Mercury ingestion
Mercury vapor inhalation
With the exception of the mandibular second premolar, the pulpal floor is normally cut at a right angle to the long axis of the tooth placing it perpendicular to the forces of occlusion.
True.
False.
False. (exception of the mandibular first premolar)
After completion of Black’s first step, the proper depth of the pulpal floor for an
amalgam preparation is:
0.25mm beyond the deepest portion of caries.
3mm from a cuspal incline.
1.5m at the central pit.
0.5mm beyond the DEJ.
0.5mm beyond the DEJ
A cavity preparation which involved the distal and incisal surfaces of tooth #23 would be called a \_\_\_\_\_cavity preparation. Class I Class II Class III Class IV Class VI
Class IV
Which phase(s) make up the matrix in a set dental amalgam? Gamma and Gamma I. Gamma and Gamma II. Gamma. Gamma I and Gamma II.
Gamma I and Gamma II
A #34 bur is an example of a(n):
Elliptical bur. (330, 331)
Tapered plain fissure bur (69, 170,171)
Long inverted cone bur. (34 is an inverted cone bur)
Tapered cross-cut fissure bur (699, 700,701)
Long inverted cone bur. (34 is an inverted cone bur)
Enamel dissolution is initiated when the intraoral pH level reaches 3.
True.
False.
False. It’s a pH of around 5.6
What is the PRIMARY source of amalgam retention in a cavity preparation? Vertical preparation walls. Grooves or pins. Mechanical undercuts. Amalgam bonding agents.
Mechanical undercuts. (syllabus #5)
Lactobacilli dominate during the ______of caries.
Onset.
Progression.
Progression
According to the hydrodynamic theory, pain transmission in the tooth:
Results from demineralization of enamel changing the surface topography of the enamel rods.
Occurs due to small, rapid movements of fluid within enamel rods. (w/in dentinal tubules)
Cannot occur because the tooth is mostly inorganic in nature.
None of the above.
None of the above
Amalgam creep occurs during the initial setting reaction of dental amalgam.
True.
False.
false - I’d go with B, at least slide 25 in the “Amalgam 6 & 7” seems to show that creep is a longer term thing after the amalgam has hardened.
Which of the following is NOT an example of resistance form for an amalgam cavity preparation?
Flat pulpal floor.
Restricting the extension of external walls.
Converging walls under cusps. (retention form)
Proper amalgam bulk.
Converging walls under cusps
When using amalgam carving strokes that are perpendicular to the preparation margin, the carver is always moved from enamel to amalgam.
True. Yeah I agree, definitely true.
False.
True
In a tooth preparation, a line angle whose apex points away from the tooth is defined as an internal line angle.
True.
False.
False
Which of the following is an abbreviation for a Class I preparation? MO. MI. DL. OL.
OL
In which area of the tooth do the enamel rods orient themselves apically as they progress from the DEJ to the external tooth surface? Cusp tips Developmental grooves Cervical No enamel rods orient apically.
Cervical
What is the highest pH at which enamel begins to demineralize?
a. 3.0 b. 4.5 c. 5.5 d. 6.5
5.5
When carving a Class I silver amalgam restoration, what is the first step that is done following the pre-carve burnish? Form grooves. Place cuspal inclines. Locate margins. The tooth is rinsed with water.
Locate margins
An external line angle is a line angle whose apex points into the tooth.
True.
False. (internal)
False
Please list 2 reasons for polishing silver amalgam restorations.
1 complete carving
2 refine anatomy, contours, and marginal integrity
3 enhance surface texture of restoration
Just FYI, this question is not on the new study guide.
A Class I lesion should not be prepared to receive a restoration until it is visible on a radiograph.
True.
False.
False
All accumulations of plaque are pathogenic. This statement is an example of:
Nonspecific Plaque Hypothesis.
Specific Plaque Hypothesis.
Nonspecific Plaque Hypothesis
Place the following in the order in which they would appear on a standard three- number formula dental hand instrument.
a. Length of the blade in millimeters.
b. Width of the blade in tenths of millimeters.
c. Number-angle of the blade from the long axis of the shaft in centigrade or hundredths of a circle.
b. Width of the blade in tenths of millimeters.
a. Length of the blade in millimeters.
c. Number-angle of the blade from the long axis of the shaft in centigrade or hundredths of a circle.
Identify which bacterium is primarily involved in each of the caries processes listed below:
_ a. Actinomyces
_ b. Streptococcus Mutans
_ c. Lactobacilli
a. Initiation of caries - MS
b. Progression of caries - Lactobacilli
c. Root surface caries - MS and Actinomyces (Caries slide 14); but mainly MS (syllabus #2)
An admixed amalgam contains both lathe-cut particles and spherical particles.
True.
False.
True
Amalgam should never be placed in patients where moisture control is difficult.
True.
False.
False
In comparison with a plain fissure bur, a crosscut fissure bur cuts:
Faster.
Smoother. (Cross-cut fissure burs leave a roughly cut surface (due to cross-cuts) that needs to be refined)
Faster
The cavosurface margin is the angle of tooth structure formed by the junction of a prepared wall and the external surface of the tooth.
True.
False.
True
Both convergence and divergence occur in the walls of a properly prepared Class I amalgam preparation in a mandibular first molar.
True
False
True
High copper alloys:
Are stronger than low copper alloys.
Are more brittle than low copper alloys.
Have higher creep values than low copper alloys.
Have higher corrosion values than low copper alloys.
Are stronger than low copper alloys. (increase copper -> increase strength, decrease creep and corrosion)
Using the four number formula for dental hand instruments define what dimensions about the instrument each number represents. Use the numbers 15-98-10-14.
15= width of the blade in tenths of a mm (in this case 1.5mm wide) 98= primary cutting edge angle measured from a parallel line with the long axis of the handle in a clockwise direction. 10= blade length in mm 14= Angle of the working end of the instrument measured from long axis of the handle in a clockwise direction.
The presence of zinc in dental amalgam:
Suppresses oxidation of the key elements in the alloy.
Can lead to delayed expansion if contaminated with moisture after setting.
Can lead to the production of hydrogen gas if contaminated with moisture after setting.
All of the above are true.
All of the above are true
Rank the following components of a dental amalgam according to strength with the strongest being number 1: gamma, gamma I, gamma II
- Gamma
- Gamma I
- Gamma II
Dead tracts extend from external dentin to the pulp and are sealed off at the pulp by secondary dentin.
True.
False. (tertiary dentin)
False. (tertiary dentin)