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)
Amalgam chemically bonds to the enamel and dentin of a prepared tooth.
True.
False. (mechanical bond)
False
Write Black’s Six Steps as listed in the syllabus and in the order which he proposed
for them.
- outline form
- resistance and retention form
- convenience form
- removal of remaining decay
- finish enamel walls
- cleanse the preparation
Which of the following will minimize amalgam expansion?
Moisture contamination during condensation.
Increased condensation pressure. (increase trituration time and condensation pressure, alloys with small particle size)
Increased mercury content.
Decreased trituration time.
Increased condensation pressure. (increase trituration time and condensation pressure, allows with small particle size)
The process of mixing the components of dental amalgam for placement into the cavity preparation is called: Spatulation Flagellation Trituration Condensation
Trituration
What is the orientation of the enamel rods in the pits and grooves of the occlusal surfaces?
Converge from DEJ to external tooth surface.
Diverge from DEJ to external tooth surface. (for cusps and ridges)
Converge from DEJ to external tooth surface
Caries involving the cervical third on the facial surface of tooth #22 is: Class I caries. Class II caries. Class III caries. Class V caries.
Class V caries
During Black’s 4th step of cavity preparation, the entire pulpal floor is lowered to the level of the deepest decay.
True.
False.
False. (pulpal floor depth should be established and then further decay removal if needed)
Condensation of dental amalgam is only done in a vertical direction because the amalgam is fluid enough to adapt to the preparation walls without any lateral condensation.
Both parts of the statement are true.
The first part is true, the second is false.
The first part is false, the second is true.
Both parts of the statement are false.
Both parts of the statement are false. (condense floors vertically and walls laterally)
Which of the following is an advantage of amalgam?
Marginal breakdown is common.
Potential for galvanic reaction.
Corrosion causes an effective seal at the tooth-restoration interface.
Public perception of mercury toxicity.
Corrosion causes an effective seal at the tooth-restoration interface.
The only exception to the rule of creating the pulpal floor perpendicular to the long axis of the tooth is: The maxillary first molar The mandibular first molar The mandibular first premolar The mandibular second molar
The mandibular first premolar
The shape and placement of preparation walls that best enables the restoration and tooth to withstand mastication forces without fracture is:
Resistance form.
Retention form.
Resistance form
Compared to low copper alloys, high copper alloys exhibit: More corrosion. Less compressive strength. More tensile strength. Less creep.
Less creep
Which of the following statements is TRUE regarding caries removal on the pulpal floor when preparing a tooth for silver amalgam?
Infected dentin can remain in a prepared tooth.
Only the caries at the DEJ needs to be removed.
Affected dentin can remain in a prepared tooth.
The entire pulpal floor is lowered until all caries is removed.
Affected dentin can remain in a prepared tooth
Which of the following is not one of the disadvantages of the slow speed handpiece? Time consuming Requires heavier force Creates vibration Greater tactile sense
Greater tactile sense
What is the primary determinant of the outline form for a cavity preparation?
Esthetics.
The extent of carious dentin. (primary determinant of the outline form is the extension of the caries)
Anatomy of the tooth.
Type of restorative material planned.
The extent of carious dentin. (primary determinant of the outline form is the extension of the caries)
What is the single most important factor in producing cariogenic plaque? Poor oral hygiene. High sucrose exposure. Genetics. Xerostomia.
High sucrose exposure
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
High copper alloys have lower creep values and better marginal integrity than conventional alloys.
a. True
b. False
True (increase copper -> decrease creep, increase strength)
It is useful to know the diameters and lengths of the burs used in tooth preparation so that they can be used as gauges of depth and distance.
True
False
true
Enamel is: Formed by odontoblasts. Mostly organic. Hardest at the DEJ. Brittle.
Brittle
Which of the following is not a requirement for amalgam preparations?
The cavosurface angle must approach 90o.
The bulk of amalgam must be a 2mm thick.
There must be adequate mechanic retention.
All of the above are requirements for amalgam preparations.
All of the above are requirements for amalgam preparations.
The cavosurface margin is the angle of tooth structure formed by the junction of a prepared wall and the pulpal floor.
True
False
False
. Enamel hardness is lowest at the CEJ.
True.
False.
False. (It’s lowest at the DEJ)
MS and Actinomyces initiate caries in pits and fissures of posterior teeth.
True.
False.
False
Increased setting expansion of a silver amalgam restoration indicates that it was over triturated.
True.
False.
False. (under trituration leads to grainy, dull, crumbles, inadequate wetting of alloy particles with Hg, rxn doesn’t proceed.
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
Mesial and distal cavo-surface margins should be parallel with the appropriate marginal, transverse or oblique ridges.
a. True
b. False
True
Allowing amalgam waste to enter rivers, streams, lakes and bays is a health risk
because
a. Bacteria in sedimentary sludge can use inorganic mercury compounds tosynthesize organic mercury compounds, which enter the marine food chain,
creating a health hazard for humans
b. Fish can metabolize inorganic compounds of mercury, releasing elemental mercury into the environment, which creates a mercury vapor risk to other life forms including humans
c. Unreacted elemental mercury in amalgam waste can be converted to inorganic mercury compounds by marine invertebrates; the inorganic mercury compounds then enter the food chain, creating a health hazard for humans.
Bacteria in sedimentary sludge can use inorganic mercury compounds to synthesize organic mercury compounds, which enter the marine food chain,
creating a health hazard for humans
When deciphering the difference between enamel and dentin which of the following is TRUE?
Dentin is harder than enamel.
Enamel is more opaque than dentin.
Dentin lightens with age.
Enamel produces a high pitch when an explorer tine passes across it.
Enamel produces a high pitch when an explorer tine passes across it.
When preparing a tooth for a silver amalgam restoration, unsupported enamel does not need to be removed.
True
False
False
Which teeth are the least susceptible to caries? Maxillary molars. Maxillary incisors. Mandibular molars. Mandibular incisors.
Mandibular incisors
When deciphering the difference between enamel and dentin which of the following is TRUE?
Dentin is harder than enamel.
Dentin is more opaque than enamel.
Dentin lightens with age.
Dentin produces a high pitch when an explorer tine passes across it
Dentin is more opaque than enamel
Which of the following is an abbreviation for a Class III preparation? MOD. MIFL. DL. L.
DL
Caries involving the distal surface of tooth #3 is: Class I caries. Class II caries. Class III caries. Class V caries.
Class II caries
Caries involving the mesial surface of tooth #9 is: Class I caries. Class II caries. Class III caries. Class V caries.
Class III caries
The Dovetail spoken of in the syllabus represents which of Black’s Six Steps?
step 2: resistance and retention form
What element is best omitted from the various combinations of alloys used in dental amalgams where it is NOT possible to isolate the restoration from moisture contamination? Sn Hg Ag Cu Zn
Zn (Zinc free amalgam is available for use in restorations where isolation is not possible. )
Which of the following is the most effective action in minimizing the risk of mercury vapor in the dental clinic environment?
a. Use pre-capsulated amalgam
b. Store fragments of old amalgam restorations under water
c. Flush wastewater lines with bleach or chlorine-containing cleaning materials.
d. Use carpet to cover floors around the dental chair.
Use pre-capsulated amalgam
Which of the following IS NOT one of the advantages of amalgam?
a. Durable
b. Esthetic
c. Economical
d. Least technique sensitive of all restorative materials.
esthetic
Ideally, with respect to the reaction, one would prefer it not get to completion, but only progress far enough to generate enough matrix to bind the _ particles together. Gamma I Gamma II Gamma Eta phase
Gamma (Only want the reaction to go far enough to generate adequate matrix (gamma I and II) to hold the unreacted particles (gamma) together.)
It is important to realize that amalgam’s tensile strength is 1/5 to 1/8 that of the compressive strength and that is why amalgam can take straight on or 90 degree
loads better than shearing loads
a. Both statements are true.
b. The first statement is true but the second is false.
c. The first statement is false but the second is true.
d. Both statements are false
Both statements are true.(SA tensile strength is ⅕ to ⅛ its compressive strength
Please list three ways you can minimize mercury vapor in the dental office.
1 using pre-capsulated amalgam_
2 Proper ventilation
3 Use a cover on the triturator_
There are lots different answers to this in the slides. Don’t carpet your office, store scraps in a sealed container, replace cap on amalgam capsule, etc.
Which of the following is not a favorable tooth habitat for pathogenic plaque?
Root surfaces
Pits and fissures
Occlusal/Incisal 1/3 of the buccal/facial surface
Subgingival areas
Occlusal/Incisal 1/3 of the buccal/facial surface
Which of the following is TRUE concerning a post-carve burnish of silver amalgam?
a. It helps to locate margins
b. It is done before the amalgam reaches its initial set.
c. It is only done for restorations that are not smooth.
d. It expresses more free mercury and increases the surface strength.
It expresses more free mercury and increases the surface strength. (syllabus #7)
As the number of blades or flutes on a bur decreases, efficiency is decreased but a smooth cut is achieved.
True.
False.
False
Which of the following is an example of resistance form for an amalgam cavity preparation? Grooves. (retention) 90 degree cavosurface angle Pins. (retention) Occlusal dovetails. (retention)
90 degree cavosurface angle
Since the operator has only 5-7 minutes to complete condensation, he/she should always use the large end the amalgam carrier to deliver the most amalgam possible to the preparation and decrease the amount of time spent condensing.
True.
False.
False
Natural ridges, free of defective grooves can usually be preserved and should not be included within cavity preparations unless less than 1 mm of sound supported tooth structure remains.
True.
False.
True
The third number in a four number formula hand instrument specifies:
a. The angle of the cutting edge from the long axis of the shaft.
b. The width of the blade in millimeters.
c. The length of the blade in millimeters.
d. The angle of the shank to the handle
the length of the blade in millimeters
In an amalgam preparation, what is the proper depth of the pulpal floor before caries is removed? 1.0mm into the DEJ. 3mm from a cuspal incline. 1.5mm at the central pit. 0.5mm into the DEJ.
0.5mm into the DEJ
If the defect due to decalcification is greater than 1/3 of the thickness of enamel,the area in question should be included within the preparation outline design and
not removed by enamoplasty.
a. True
b. False
true
The high speed handpiece is ideal for high tactile sensitivity and smoothness of the finish on the preparation walls.
True
False
False
longer one takes to condense the amalgam, the greater the chances of having a restoration with a greater than 1:1 mercury to alloy ratio.
True
False
true
During periods of remission in the caries process, bacteria are decreasing in metabolic activity, teeth are remineralizing and the pH of the oral environment is decreasing.
True.
False.
False. (pH will be increasing)
Which of the following statements about amalgam strength is FALSE?
Voids in dental amalgam decrease strength.
Amalgam strength is greatest 1 hour after placement.
High copper alloys are stronger.
Under trituration of amalgam decreases strength.
Amalgam strength is greatest 1 hour after placement.
The condensation pressure delivered to the amalgam during condensation is directly proportional to the area of the face of the nib.
True
False
False (inversely related with the area of the nib; larger nib= less pressure delivered to the amalgam so you would need more condensation force)
A twelve bladed finishing bur is more efficient for cutting tooth structure than the standard round bur but the surface finish is rougher.
Both statements are true.
The first statement is true but the second is false.
The first statement is false and the second is true.
Both statements are false.
Both statements are false.
Which elements compose the gamma phase in the setting reaction for silver amalgam? Silver and Mercury. Copper and Tin. Tin and Mercury. Silver and Tin.
Silver and Tin. (gamma = Ag3Sn)
Which of the following factors DOES NOT contribute to increased expansion of amalgam? a. Too high Hg/alloy ratio. b. Undertrituration. c. Overtrituration. d. Moisture contamination
overtrituration
Class II caries penetrates enamel as a cone with the apex oriented toward the DEJ and penetrates the dentin as a cone with the apex oriented pulpally.
True.
False.
True
The advantage of carbon steel used in handheld instruments designed for cutting tooth structure intraorally is that it will not rust or corrode.
True
False
False
Round burs are primarily used for caries removal in a high speed handpiece.
True.
False.
False (slow speed)
Most dental burs have a: Positive rake angle. Radial rake angle. Negative rake angle. Neutral rake angle.
Negative rake angle.
. Secondary dentin lacks dentinal tubules and continues deposition throughout the life of the tooth.
True.
False.
False. (Secondary dentin tubules are irregular, and continues deposition throughout the life of the tooth)
Which of the following is FALSE concerning condensation of dental amalgam?
The operator applies 6-10 pounds of thrust.
The operator has about 5-7 minutes to complete condensation. (false)
The technique must be orderly, stepwise, and overlapping.
Overpacking is done to ensure the removal of the mercury rich surface during carving.
The operator has about 5-7 minutes to complete condensation
MS and Actinomyces initiate caries in pits and fissures of posterior teeth.
True.
False.
false
Name the three most common types of amalgam alloy based on particle geometry and size.
_Lathe cut- irregular shaped
_Spherical
_Admixed (⅔ lathe cut, ⅓ spherical)
