Midterm Test Files Flashcards
What is the problem seen with buccal and lingual axial walls? Picture shown.
Over
converged.
What technique is most appropriate for single unit interim crowns?
Direct Technique.
Adequate facial reduction with greater reduction in — than —.
cervical
incisal
Consider indirect vs. direct with PMMA.
Protects pulp from thermal and chemical damage.
T/F Facial proximal and lingual proximal line angles are preserved for resistance.
True (Rotational
on horizontal axis)
Which of the following are not recommended?
Using binoculars.
Long story, patient has rampant caries and plaque; how do your treat?
Patient needs to be
motivated, use amalgam instead, fixed treatment not planned until hygiene under control.
What type of finish line is used on a colarless metal-ceramic?
Shoulder without bevel.
Patient presents with TMJ and muscles problems; how do you treat?
Further evaluate.
Metal-ceramic crown.
Shoulder line supports.
Metal ceramic photo.
Incisive and facial is under reduced.
Patient has occlusal disharmonies; what do you do?
Articulate casts and perform an intra
oral exam.
As wall height decreases, resistance decreases. Arc of rotation happens more in teeth with
wider bases.
Standard not met for occlusion. Excursive movements show marks. Adjacent teeth don’t
hold shim stock.
Occlusal posterior clearance for cast gold (full metal).
1.0-1.5mm
Metal crowns can be used everywhere except where.
Intact facial and lingual. (Sorry, don’t
remember actual wording)
All-ceramic crowns are avoided where?
In occlusal contact in cervical 1/5.
All-ceramic crowns fracture when what is present?
Sharp axial line angles.
Short walls cause inadequate resistance.
Improved with grooves and boxes. (Arc of rotation)
T/F Posterior metal-ceramic occlusal reduction is 1.0mm.
False (1.5 for porcelain and 0.5 for
metal. 2 total)
What has the greatest polymer shrinkage and causes exothermia?
PMMA
Path of insertion is ____
Aligned with long axis, parallel contacts, minimum axial reduction.
T/F Prepare axial with full depth of bur.
False (Will cause a lip)
Photo shown with knife edge finish line. What is wrong?
Inadequate reduction of finish line
Chamfer for a metal crown has an axial depth of?
0.3-0.5mm.
An articulator and face bow are used to?
Closely approximate position of posterior teeth and
record mandibular movements.
Seating groove placed at what angle to Finish line?
90º
What instrument is used to refine internal line angles?
Hatchet
T/F? Incisor occlusal-cervical minimum height is 2mm.
T/F? Occlusal-cervical:Facial-lingual = 0.4.
False, True. (3mm, 0.4)
What is the purpose of a seating groove?
Limits the path of insertion, cast during
cementation, and prevents rotation.
Tooth preparation is done with all of the following except?
Occlusal-cervical:facial-lingual is
0.25.
Lack of inter proximal contacts will cause which of the follow?
Drifting of adjacent teeth and
prepared tooth.
Complete conversion of MMA monomer to PMMA causes.
Increased rigidity and strength.
Incisal reduction of anterior metal ceramic.
2-2.5mm
Why is a chamfer used for a cast metal restoration?
They are easy to form, adequately
distinct on the tooth and die, and provides sufficient space that the metal is adequately rigid.
essay: what was wrong with the prep shown on the interproximal surfaces?
Overconverged
essay: what was wrong with the prep shown on the facial surface?
Cervical not 1.2 and incisal
not 1.5-1.7
short answer: short walls cause loss of resistance. To fix this you
add restorative material or
grooves
essay: what was wrong with the prep shown?
Part had supragingival margin and part had
subgingival
picture of knife-edge
axial depth of chamfer should not be wider than half of the depth of the bur used: T/F
T
don’t use full crown if only have moderate caries and good facial/lingual walls Gave
“all of the above are true except:”
rampent caries that can’t get under control,
don’t do fixed prosethetics until they have it
under control
path of insertion should be parallel to the long axis, parallel to proximal contacts, one more
thing
All of the above
preparing without appropriate contact causes
drifting, issues with final restoration,
inflammation
cervical 1/5
don’t want
- preparation in hypo-occlusion:
no problem; interim in hypo-occlusion, final will be in hyper
use — for indirect
bis-acryl
PMMA is most
exothermic and most shrinkage
axial reduction 1.5-2 T/F
false
toxicity and low physical strength with
free monomer
— is termination
eugenol
OC:FL ratio is 0.25: T/F
F
reduction on occlusal for porcelain should be 1 mm: T/F
F
SNM: need shimstock to be on all teeth and black and red don’t match
B and C were correct
wall length too short decreases resistance and seen in teeth with
larger diameters
ideal margin for chamfer depth is
.3-.5
seating groove helps with
stop rotation, parallel to long axis and something else
— is most important for all ceramic
round line angle
grooves should be — degrees to disposing forces
90
forces coming in FL put grooves in
MD
MC with porcelain collar: what finish line do you do?
Shoulder for strength
adequate axial reduction use
2 plane
incisal reduction on the anterior was
2-2.5
if patient is in pain
do further examination
articulator to facebow approximates
posterior contacts in mandibular movement
how to evaluate proper occlusion:
intraoral exams and diagnostic casts
The purpose of a face-bow transfer to a semi-adjustable articulator is to?
The close approximation of posterior determinants for mandibular movement
Occlusal disturbances are evaluated
Intraoral exams
Articulated diagnostic casts
- In the picture to the Right, tipping forces are due to
Resistance
As one axial wall gets shorter as compared to the wall
of the tooth, resistance form ___________ , this happens
most often in teeth with _____________ bases
a. Decreases, larger
The treatment plan for a patient with rampant caries
and plaque
accumulation is
a. To place amalgam restorations to preserve the teeth until the caries/plaque is under control
b. Not doing prosthodontic treatment until the caries/plaque is under
control
c. Motivate the patient to control their oral health and have good oral
hygiene
d. All of the above are true
- If you reduce the facial surface in a one-plane method of metal-ceramic and
all-ceramic crowns, this can cause:
a. Possibility to pulp exposure
c. Bright spots are evident on the porcelain
d. Block like over contoured incisal edge
List two consequences if a metal-ceramic crown preparation is performed without adequate 2
plane reduction
Overcontouring of which regions will cause displacement in the facial
direction?
d. Lingual just above the cingulum
- The facial shoulder on a metal-ceramic crown should
a. Extend lingual to the interproximal contact
- The wall of an anterior tooth preparation should be 2 mm when the TOC is
between 10-12 degrees. The occlusal-cervical : facial-lingual ratio should be 0.4 or higher on all
teeth
c. 1st statement is false, second statement is true
The wall of all teeth besides molars should be 3 mm and molars should be 4 mm. > same
question idea, but was asked in an “in a study all of the following are true about adequate crown
preps EXCEPT” and the incorrect answer was OC/FL ratio is at least 0.25 in all teeth (want 0.4)
The seating groove
a. Prevents rotational movement
b. Limits the path of insertion to 1 direction
c. All of the above are true
- The path of insertion should be
a. Parallel to the long axis of the tooth
b. Parallel to the proximal contact points to allow seating
- Which of the following methods are not used to evaluate the occlusal
convergence
a. Binocular vision through the mirror
- In a FGC, the nonfunctional cusp should be reduced ____ mm and the
functional cusp should be reduced _____ mm
b. 1.0, 1.5
- The chamfer depth on a metal-ceramic crown should be
a. 1.0-1.2mm
- A chamfer margin should be developed by using a —
with the diameter of the desired chamfer depth and you should bring the chamfer to the — of the diamond diameter
tapered diamond bur
full depth
- When a patient exhibits pain or dysfunction
b. Further examine the patient to alleviate pain before you begin treatments
- In a collarless metal ceramic anterior crown (porcelain labial margin) what
type of margin should be used? (Open answer)
a. Radial shoulder at 90 degrees
- With a metal-ceramic crown, which of the following is true concerning the
finish line on the facial surface
A shoulder is used on the facial and a chamfer is used on the lingual
- With all-metal ceramic crown, why is a chamfer used
a. Better able to detect with impressions/dies
b. Uses an acute angle for good closure of the margins and a closer fit
c. Ease of placement
d. All of the above are true
- Margins on cast restorations should be placed
b. On enamel supragingivally
- Which of the following shows a Chamfer - A
- Which of the following shows a Knife edge- D
- Which of the following shows a Beveled shoulder C
- Which of the following shows a Radial shoulder B
22.Open proximal contacts of a temporary restoration can cause
b. Excessive adjustment of the permanent restoration
c. Tooth Migration
i. The proximal contacts has nothing to do with the supra or infraocclusion. It leaves room
between the prep and the adjacent teeth so the prep can migrate before permanent restoration is
installed.
- It is desirable to convert all of the free monomer into polymer because
a. Unreacted monomer is toxic
b. Better mechanical properties
- Metal ceramic restorations are indicated in all of the following except
c. Moderate carious lesions
- All-ceramic crowns should not be used on anterior teeth if
a. Opposing contact is on the cervical 1/5
- Which of the following do NOT decrease the likelihood of fracture in
all-ceramic crowns
a. Sharp line angles*
- Which of the following should not be used to polish/contour acrylic resins
a. Diamond points on high speed
- Occlusal prematurities/eccentric stops are detrimental to molars because
a. Off-axial loading due to the closeness of the muscles of
mastication
- When you start to make an anterior all ceramic preparation,
a. Axial wall depth grooves cut on the facial
- A groove placed in a preparation should
a. Be 90 degrees to the axial wall
- On a metal-ceramic crown
c. The mesial and distal walls should be perfectly parallel
i. Ideal incisal reduction is 2.0-2.5mm.
ii. The mesial and distal walls should be relatively close to parallel but they should still be a
little converged. > “in a clinical study it was shown that adequate axial cervical reduction for a
MCC prep can safely be placed at a depth of 2.0-2.5mm without risking exposure of the pulp”
True/ False
True
- To increase resistance to faciolingual horizontal dislodgment, where should
you place grooves
b. Mesial & distal surfaces
- In a posterior metal ceramic crown preparation 1.00 mm occlusal reduction
should be reached when the occlusal surface is being restored with porcelain
T/F
b. False Want 2mm
- Why is a chamfer margin recommended for a metal crown margin?
a. Allows for clean margin finishing
b. Easy to place and identify on a die
c. Allows for a thin margin while maintaining adequate bulk of metal
Nearby
d. All of the above
- What problem is visible with the axial walls in this preparation (open
answer)
- Assuming the bur is held parallel to the long axis of the tooth, what problem
is present? (Open answer)
- Inadequate axial reduction on this tooth resulted in a thin margin pictured,
what type of margin is this?
The purpose of a face-bow transfer to a semi-adjustable articulator is to?
b. The close approximation of posterior determinants for mandibular
movement
Occlusal disturbances are evaluated
a. Intraoral exams
In the picture to the Right, tipping forces are due to
a. Resistance
The treatment plan for a patient with rampant caries and plaque accumulation is
a. To place pin-retained amalgam restorations until the caries/plaque is under
control
b. Not doing prosthodontic treatment until the caries/plaque is under control
c. Motivate the patient to control their oral health and have good oral hygiene
d. All of the above are true
- If you reduce the facial surface in a one-plane method of metal-ceramic and all-
ceramic crowns, this can cause:
a. Possibility to pulp exposure
Overcontouring of which regions will cause displacement in the facial direction?
Lingual just above the cingulum
The facial shoulder on a metal-ceramic crown should
a. Extend lingual to the interproximal contact
- The wall of an anterior tooth preparation should be 2 mm when the TOC is between
10-12 degrees. The occlusal-cervical : facial-lingual ratio should be 0.4 or higher on
all teeth
c. 1 st statement is false, second statement is true
- The seating groove
a. Prevents rotational movement
b. Limits the path of insertion to 1 direction
c. All of the above are true
- The path of insertion should be
a. Parallel to the long axis of the tooth
b. Parallel to the proximal contact points to allow seating
Which of the following methods are not used to evaluate the occlusal convergence
a. Binocular vision through the mirror
- In a FGC, the nonfunctional cusp should be ____ mm and the functional cusp should
be _____ mm
b. 1.0, 1.5
- The chamfer depth on a metal-ceramic crown should be
a. 0.3-0.5 mm
Open proximal contacts of a temporary restoration can cause
b. Excessive adjustment of the permanent restoration
c. Tooth Migration
d. B and C are true
- It is desirable to convert all of the free monomer into polymer because
a. Unreacted monomer is toxic
b. Better mechanical properties
c. A and B are true
- Eugenol will cause
a. Termination
- Which of the following is the best for direct technique and over-matrix method
c. Bis-acryl resin
- When using PMMA, a reason that you would want to choose the indirect over direct
technique is
a. Protection of the tissues and pulp from heat/chemicals
- Metal ceramic restorations are indicated in all of the following except
c. Moderate carious lesions
- All-ceramic crowns should not be used on anterior teeth if
a. Opposing contact is on the cervical 1/5
- Which of the following do NOT decrease the likelihood of fracture in all-ceramic
crowns
a. Sharp line angles
- Which of the following should not be used to polish/contour acrylic resins
a. Diamond points on high speed
- Occlusal prematurities/eccentric stops are detrimental to molars because
a. Off-axial loading due to the closeness of the muscles of mastication
- When you start to make an anterior all ceramic preparation,
a. Axial wall depth grooves cut on the facial
- A groove placed in a preparation should
a. Be 90 degrees to the axial wall
- On a metal-ceramic crown
a. Approaches the pulp quickly if the reduction is greater than 1.2-1.5 mm
1.) All of the following are okay in all ceramics except:
Sharp line angles
Rationale for facebow with semi adjustable-
close approx. of post determinants
Pic with oblique force and tipping-short walls are bad for:
resistance
Label pic of knife vs radial shoulder vs chamfer vs shoulder bevel (this was 4 different questions)
Why chamfer is indicated:
(all of the above: acute angle with metal, ease of ability etc).
What finishing bur not for acrylic?
diamond point on highspeed
2 mm wall ok (false) and oc: cl .4 or greater
(true?)-
w/o proximal contact in provisional: what happens:
food impaction/perioinflamm and mesial
drift leading to more final adjustments or remake needed
eugenol leads to:
termination
reason for indirect provisional:
protection of pulp from exothermic heat
why you want monomer fully reacted:
toxic, stronger physical properties
final properties of polymer or something like that
what to do when pt exhibts tmj/occlusal problems:
further exam
what to do to evaluate occlusion:
intraoral exam, diagnostic casts
how NOT to view undercuts:
bioccular vision
groove helps with
path of insertion, proper seating, resistance to rotation,
ant ceramic-unfavorable with
occlusal contact in cervical 1/5
where to start when making an anterior PFM or all ceramic prep:
axial wall depth
grooves cut on facial
finish line placement for gold:
supragingival and on enamel
consequence of one plane (versus 2 plane) reduction from gingival
headlight from
opaque porcelain and block like over contouredincisal edge
porcelain coping on pfm best margin:
shoulder
best part of resistance on all ceramic:
cingulum– get facial dislodgement is over reduce
the lingual cingulum
path of insertion – determine by:
long axis of the tooth, parallel to the proximal contact
– complete when groove is placed???
FGC –
functional cusp reduction – 1.5mm, non-functional cusp reduction – 1.0mm
Rampant caries –
motivate pt to have good oral hygiene and control ds, no fixed tx
under under control, amalgam with pin
Eccentric contacts – premature molar contacts - ??
possible answers had to do with axial
and non-axial loading
How far do you extend the facial shoulder on metal ceramic crown –
all the way past
interproximal contacts – onto the lingual
Groove – want — degrees to axial wall
90
Best material for temp crown for direct, over matrix method:
bis-acryl resin
On pediatric patient which is ok -
2mm reduction on incisal or 1.5 mm axial
reduction? [not sure which is correct]
On PFM, where does shoulder meet with chamfur?
Lingual to proximal.
Clinical studies which provides better seating of porcelain crown: answer:
beveled shoulder. [is this correct?]
