Amalgam Quiz Flashcards
What brand of amalgam do we use in lab?
permite c
extended carving time
What type of amalgam is permite c extended carving time?
high copper, admix (spherical + lathe cut)
Zn containing (0.2%)
Name the tooth surfaces of a Class V preparation
axial floor
gingival wall
incisal wall
ALL MY DEAD FERRET LOVES ONION CHIP PARTIES
Axial Mesial Distal Facial Lingual Occlusal/Incisal Cervical/Gingival Pulpal
What is the purpose of a matrix band?
isolate the preparation
condense amalgal against band
restore proximal contact and contour
What is the purpose of a dental wedge?
separate teeth to allow width of matrix band (tight contact)
seal gingival margin of proximal box
prevent overhang
How many wedges do you use for a MOD preparation?
2
one distally and one mesially
bot inserted from lingual embrasure
How long should you wait to polish an amalgam resotration
wait until amalgam has fully set (24 hours after placement)
What is the 2-2-2-2 rule
for pin placement
2mm pin hole depth
2 drill diameters inwards from DEJ
2 mm pin length
2 mm amalgam above pin
When is it necessary to place a pin?
when a cusp is missing or removed due to caries
2/3rds rule applies for this^
When is a cusp missing or removed due to caries?
2/3rds rule!
if 2/3 cusp tip to cusp tip
if 2/3 from central groove to cusp tip
must do a pin placement
What type of pins do we use in lab?
minim silver
THREADED TYPE
self shearing
What size PIN DRILL did we use in lab?
0.021/0.53 inch/mm
What size PIN did we use in lab?
0.024/0.61 inch/mm
How should the pill drill be oriented when placing a pin channel in a tooth?
parallel with root surface
to prevent pulping or damage to external tooth
Where should pins be located?
2 pin diameters inward from DEJ
at the line angle associated with the missing cusp
Mesiobuccal cusp taken off…. the pin is plcaed at the ___ line angle
mesiobuccal line angle
Ideal pulpal depth is ____
0.5mm into DEJ (into dentin)
but need 1.5mm for adequate amalgam condensing
Ideal axial depth for class II prep is ___
0.5-0.75mm into DEJ
but need at least 1.0mm to properly condense in proximal box
Where do caries occur on the proximal surface of a posterior tooth?
gingival to the proximal contact
This is why we can see them radiographically and not clinically
List sequence of materials for minimal caries
RDT more than 2mm
LINER (copal varnish) –> Amalgam
List sequence of materials for moderate caries
RDT is 0.5 - 2mm
Base (GI) –> LINER (copal varnish) –> Amalgam
List sequence of materials for asymptomatic deep caries
RDT is less than 0.5 mm
Near pulp exposure (indirect pulp capping)
Liner (Dycal, CaOH) -> Base (GI) -> Liner (copal varnish) -> Amalgam
List sequence of materials for deep caries with questionable pulp status
RDT is less than 0.5mm
Liner (Dycal, CaOH) -> Conditioner -> Base (RMGI) -> Liner (copal varnish) -> Amalgam
What is the mixing/trituration time for amalgam
7 seconds
What is the working time of amalgam
5 minutes
What is the carving time of amalgam
7 minutes
Describe an open margin in restoration
catches explorer both directions
caused by overcontouring or inadequate condensing
restoration must be replaced
Describe flash in a restoration
catches explorer tooth to amalgam
excess material will chip off and undermine restoration if mixed
flash must be carved flush with cavosurface margin of prep
Describe submarginal margin in restoration
catches explorer amalga to tooth
caused by overcarving
if less than 0.2 mm -> enameloplasty
if more than 0.2mm -> replace restoration
What happens if you increase trituration time of amalgam?
soup consistancy
sets prematurely
What happens if you decrease trituration time of amalgam?
dull, grainy/crumbly appearance
difficult to work with
decreased strength
What is the weakest phase in low copper amalgam
gamma 2
results in low corrosion resistance leading to marginal breakdown
