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