Lab Station Exam Flashcards
Alignate impression mixing time:
45-60 sec
Time available from start of mixing time to final time at which impression can be seated without distortion:
Working time
Time required for solution to gel reaction:
Setting time
Setting time may also be called:
Gelation
Setting time for alginate impression:
3-4 minutes
What should the thickness of uniform distribution of an alginate impression material be:
2-6mm
Describe how to remove an impression from patients mouth:
Sharp snapping action after breaking border seal, do not twist or rock
Criteria for accurate casts:
- Free of _____/____
- Surface should be ___, ___ & free from ____
- Should extend to all ____
- Base should be ____ thick at thinnest place
- Base should be ____
- Base should not interfere with ______
- Casts should have a horizontal land area of _____ at the _____
- Side walls of the base should be trimmed ____
- Should be accurate & in _____; otherwise remake
- Should appear ___ & free from any ___ & ____
- voids/nodules
- hard, dense; grinding sludge
- required areas
- 10-15mm thick
- Flat
- articulation
- 2-3mm; periphery of vestibule
- vertical
- MIP
- clean; debris or sludge
Label A-D:
a) Facebow
b) Index/levels
c) Transfer assembly
d) Orbital pointer
The type of facebow used in lab:
Arbitrary type: Denar slidematic facebow
What is the purpose of a facebow:
Record spatial relationship of maxillary arch to anatomic reference points
How do we determine the third point of reference?
43mm from maxillary incisor incisal edge
The third point of reference should be:
Repeatable & reproducible
Label A-E:
a) upper member
b) lower member
c) anterior/incisal pin
d) mounting ring
e) condylar mechanism
What type of articulator is an Arcon?
Semi-adjustable
Describe an Arcon Semi-adjustable articulator:
Condyles in lower member & condylar inclination in upper member
The purpose of an articulator is:
A mechanical device that simulates mandibular movements of condyles in their fossa
When articulating the lower cast, adjust the incisal guide pin to ____ & use:
0 degrees; 2-step mounting technique
Tooth dependent position which is independent of condylar position:
Maximum intercuspation
Describe MI:
Maximum intercuspation- tooth dependent position independent of condylar position
TMJ dependent position which is independent of tooth position:
Centric relation
Describe CR:
Centric relation- Condyles in most anterior-superior position, independent of tooth position
Important for deprogramming muscles of mastication to achieve and successfully record CR:
Anterior Deprogrammer
Anterior deprogrammer is important for ____ to achieve & successfully record _____
Deprogramming muscles of mastication; CR
What is this device & describe its function:
Anterior deprogrammer: important for deprogramming muscles of mastication & to achieve & record CR
What is this device & describe its function:
Leaf Gauge- finds the first point of contact in CR
A leaf gauge finds the _____ in _____
First point of contact; CR
Label A-E:
a) functional cusp bevel
b) retention groove
c) axial reduction
d) chamfer margin
e) morphologic occlusion reduction
On a #19 full gold crown prep reduction:
a) Functional cusp bevel:
b) Retention groove:
c) Axial-depth reduction
d) Chamfer margin
e) Functional cusp:
f) Central foss
g) Non-functional cusps
a) 1.5 and tapers to 1.0mm
b) full depth of 170L bur
c) 0.5 to 1.0mm
d) 0.5mm
e) 1.5mm
f) 1.5mm
g) 1.0mm
The morphologic occlusal reduction includes the reduction of:
Functional cusps, central fossa & non-functional cusps
On a #19 full gold crown prep what is reduced further, the functional or non-functional cusp?
Functional cusp
What is used for the preliminary crown impression?
Reduction index (Putty matrix)
What is the purpose of the reduction index made from putty matrix?
Evaluate occlusal reduction
29 All ceramic crown preparation guidelines:
a) occlusal reduction:
b) axial reduction:
c) occlusal convergence:
d) cervical finish line:
e) ______ line angles
f) occlusocervical length:
a) 1.5-2.0 mm
b) 1.5 mm
c) 6-10 degrees
d) 1.0 mm
e) rounded
f) greater than 3 mm
Posterior crown reduction criteria:
_____mm margin
_____ mm axial
_____ mm occlusal
______ internal/external line angles
____ shoulder margin design or ____
1.0-1.2mm margin
1.5mm axial
1.5-2.0mm occlusal
Rounded internal/external line angles
Modified shoulder margin design or heavy chamfer
A cerec crown can be made of:
- Zirconium
- Glass ceramic
- Ceramo-metal
A Cerec crown compared to a full gold crown requires:
More rounded & reduction of prep is needed
What are the steps to Cerec crown preparation:
- Scan
- Mill
- Stain
- Glaze
- Fire
The first step in making a custom anterior guide table:
Mix monomer (liquid) and Duralay- Methyl Methacrylate Resin (powder)
When making a custom anterior guide table, what is the liquid? What is the powder?
Liquid= monomer
Powder= Duralay (methyl methacrylate resin)
When making a custom anterior guide table, the casts will be in:
MIP
When making a custom anterior guide table, the upper member of articulator should:
Open/close WITHOUT interferences
When making a custom anterior guide table, there should be a _____ of the incisal pin as it _____
There should be a clear undisrupted view of the incisal pin as it contacts the custom table
When making a custom anterior guide table, the pin should be contacting the table during:
Excursive movements
When making a custom anterior guide table, the pin should be contacting the table throughout excursive movements, and the anterior teeth:
Should be in contact throughout the movement as well
When we waxed crowns #6 & #8, we set the stone casts to ______ & evaluated _____ & _____
MIP; Right lateral excursive & protrusive
When we waxed crowns #28, #29 & #30, we used _____ to check for interocclusal contact
Delar powdered wax
When we waxed crowns #28, #29 & #30 the Delar powdered wax was used to check:
Interocclusal contacts
When we waxed crowns #28, #29 & #30, the stone casts were set to _____
MIP
In posterior teeth:
Functional cusp=
Nonfunctional cusp=
Functional cusp= buccal
Nonfunctional cusp= lingual
When we waxed crowns #28, #29 & #30 we evaluated what movements?
Excursive & Protrusive
When we waxed crowns #28, #29 & #30
The ML cusp of the maxillary first molar should contact:
Central fossa of #30
When we waxed crowns #28, #29 & #30
The _____ of _____ should contact the central fossa of #30
ML cusp of the maxillary first molar
One cusp occluding in three different areas of opposing tooth:
Tripodization
When we waxed crowns #28, #29 & #30
The distal cusp tip of #30 should contact:
Distal fossa of maxillary first molar (only cusp that does not occlude with the opposing fossa)
Shim stock is used to evaluate:
Occlusal contacts
Used to evaluate where occlusal adjustments need to be made:
Articulating paper
Describe ideal contacts of posterior teeth:
Posterior teeth should have multiple, even, B/L &b simultaneous occlusal contacts
Describe ideal contacts of anterior teeth:
Anterior teeth should have lighter occlusal contacts when posterior teeth are in MIP
Why should anterior teeth have lighter occlusal contacts when teeth are in MIP:
Because anterior teeth are not axially loaded
In MIP the desired outcome=
Centric stops
Describe the desired outcome of MIP (centric stops) (3):
-Atleast three maxillary & three mandibular teeth in each quadrant are contacting
-Most of the anterior teeth are contacting
-Anterior teeth exhibit lighter contacts than posterior teeth
It is recommended to adjust _____ vs. _____
Adjust the enamel layer of maxillary lingual fossa vs. adjusting the incisal edges
Why is it recommended to adjust the enamel layer of maxillary lingual fossa vs. incisal edges when possible:
To avoid altering esthetics
Describe working side interference during lateral excursive movements:
Inner inclines of maxillary buccal cusps & outer inclines of mandibular buccal cusps
Describe non-working or balancing interference during lateral excursive movements:
Inner includes of maxillary lingual cusps & inner inclines of mandibular buccal cusps
Working side interferences or non-working or balancing interferences occur during:
Lateral excursive movements
Interferences during protrusive movements:
Anterior guidance should be present during ____
Excursive movements
During excursive movements, anterior teeth should:
Disclude the posterior teeth during excursive movements
Maxillary arch working cusps:
Lingual cusp (6)
Maxillary arch non-working cusps:
Buccal cusp (6)
Mandibular arch working cusps:
Buccal cusp (7)
Mandibular arch non-working cusps:
Lingual cusp (6)
How many centric occlusal contacts should be present per side in the maxillary arch:
6 per side
(Maxillary Arch) Describe protrusive pathway:
From centric occlusion contact –> mesial
(Maxillary Arch) Describe working pathway:
From centric occlusion contact –> mesial/buccal
(Maxillary Arch) What side is the working side during a right lateral shift:
Right side
(Maxillary Arch) What side is the working side during a left lateral shift:
Left side
(Maxillary Arch) Describe the non-working pathway:
From centric occlusion –> lingual
(Maxillary Arch) What side is the non-working side during a right lateral shift:
Left side
(Maxillary Arch) What side is the non-working side during a left lateral shift:
Right side
In the mandibular arch, how many centric occlusion contacts are present per side?
5 per side
In the mandibular arch, describe protrusive pathway:
From centric occlusion contact –> distal
In the mandibular arch, describe working pathway:
Fron centric occlusion contact –> lingual
In the mandibular arch, what side is the working side during a right lateral shift?
Right
In the mandibular arch, what side is the working side during a left lateral shift?
Left
In the mandibular arch, describe the non-working pathway:
From centric occlusion contact –> distal/buccal
In the mandibular arch, what side is the non-working side during a right lateral shift?
Left
In the mandibular arch, what side is the non-working side during a left lateral shift?
Right
What is the purpose of an occlusal guard?
Improve muscular pain condition & protect teeth & support structures
How does an occlusal guard improve muscular pain conditions?
By altering sensory input to CNS
What does an occlusal guard protect teeth/supportive structures from?
Abnormal occlusal forces
A stabilization appliance is usually for:
Maxillary arch
The purpose of a stabilization appliance is to:
Eliminate orthopedic instability between occlusal position & joint position
Treat muscle pain disorders
In a stabilization appliance, the condyles will be:
In most stable musculoskeletal position the same time as teeth are contacting evenly/simultaneously
